Glacier Retreat and Glacial Lake Outburst Floods (GLOFs)
Glacier Retreat and Glacial Lake Outburst Floods (GLOFs)
- Adam EmmerAdam EmmerCharles University in Prague, Czech Academy of Sciences
Glacier retreat is considered to be one of the most obvious manifestations of recent and ongoing climate change in the majority of glacierized alpine and high-latitude regions throughout the world. Glacier retreat itself is both directly and indirectly connected to the various interrelated geomorphological/hydrological processes and changes in hydrological regimes. Various types of slope movements and the formation and evolution of lakes are observed in recently deglaciated areas. These are most commonly glacial lakes (ice-dammed, bedrock-dammed, or moraine-dammed lakes).
“Glacial lake outburst flood” (GLOF) is a phrase used to describe a sudden release of a significant amount of water retained in a glacial lake, irrespective of the cause. GLOFs are characterized by extreme peak discharges, often several times in excess of the maximum discharges of hydrometeorologically induced floods, with an exceptional erosion/transport potential; therefore, they can turn into flow-type movements (e.g., GLOF-induced debris flows). Some of the Late Pleistocene lake outburst floods are ranked among the largest reconstructed floods, with peak discharges of up to 107 m3/s and significant continental-scale geomorphic impacts. They are also considered capable of influencing global climate by releasing extremely high amounts of cold freshwater into the ocean. Lake outburst floods associated with recent (i.e., post-Little Ice Age) glacier retreat have become a widely studied topic from the perspective of the hazards and risks they pose to human society, and the possibility that they are driven by anthropogenic climate change.
Despite apparent regional differences in triggers (causes) and subsequent mechanisms of lake outburst floods, rapid slope movement into lakes, producing displacement waves leading to dam overtopping and eventually dam failure, is documented most frequently, being directly (ice avalanche) and indirectly (slope movement in recently deglaciated areas) related to glacial activity and glacier retreat. Glacier retreat and the occurrence of GLOFs are, therefore, closely tied, because glacier retreat is connected to: (a) the formation of new, and the evolution of existing, lakes; and (b) triggers of lake outburst floods (slope movements).
- Glacial Lake Outburst (GLOFs)
Climate change, driven by natural and anthropogenic factors (see Crowley, 2000; Hansen et al., 1998; Stoffel et al., 2015), and its consequences have become a major issue in science (IPCC, 2013). Glacier ice loss—direct evidence of changing climatic conditions—is observed in the vast majority of glacierized areas around the world, including both high-latitude (arctic) and high-altitude (mountainous) regions (Barry, 2006; Overpeck et al., 1997). Glacier ice loss (glacier retreat) is accompanied by various processes, such as the formation and evolution of glacial lakes and lake outburst floods (Clague et al., 2012; Evans & Clague, 1994; O’Connor & Costa, 1993). Glacial lakes and glacial lake outburst floods (GLOFs) are attracting substantial scientific attention, for the following reasons: (a) erosion-accumulation interactions and sediment dynamics affect various spatial and temporal scales (Maizels, 1997; Morche et al., 2007; O’Connor et al., 2015); (b) they may provide a proxy data source for palaeoenvironmental reconstructions (Bauer et al., 2004; Carrivick & Tweed, 2013; Margold et al., 2011; O’Connor & Costa, 2004); and (c) they may represent a threat to society in settled areas (Carey, 2005; Carey et al., 2015; Carrivick & Tweed, 2016; Haeberli & Whiteman, 2015; Hewitt, 2016; Reynolds, 2003). Accordingly, Emmer et al. (2016a) showed an annual nonlinear increase in the number of scientific publications focusing on GLOFs recently.
For a comprehensive reference-style overview of the relation between glacier retreat and GLOFs, especially in the context of recent (post-Little Ice Age) climate change, special attention has to be given to the causes and mechanisms of lake outburst floods from different subtypes of glacial lakes, their hydrological and geomorphological significance, and their societal impacts.
Table 1. Definition of Terms
Lake outburst flood (LOF)
Sudden release of (part of) retained water from the lake
Glacial lake outburst flood (GLOF)
Lake outburst flood originating from any subtype of glacial lake
GLOF originating from ice-dammed lake
Volcanic activity-induced GLOF (release of water melted by volcanic activity)
Richardson and Reynolds (2000a)
Cause of GLOF
Direct trigger of GLOF (see “Causes and Mechanisms of GLOFs”)
Emmer and Cochachin (2013)
Mechanism of GLOF
The way of water release from the lake (see “Causes and Mechanisms of GLOFs”)
Emmer and Cochachin (2013)
Recent Glacier Retreat and Formation of Lakes
Climate Oscillations, Glaciation Cycle and Recent Glacier Retreat: An Overview
The Quaternary Context
The Quaternary period (2.588 million years ago to present—BP; Gibbard et al., 2010) is characterized by numerous climate alterations: ice ages (glacial periods) and interglacial events (Hewitt, 2000). In general, colder glacial periods are characterized globally by a larger glacierized area, while during interglacial events, the ice extent is lesser. Based on marine oxygen-isotope stages (MIS), over a hundred alternations of warmer and cooler paleoclimates occurred during the Quaternary period (see also Bintanja et al., 2005; Lisiecki & Raymo, 2005). The last glacial period occurred from approximately 110,000 to 11,700 BP; later on, the interglacial Holocene epoch began. The Holocene epoch is also characterized by climate conditions variable in space and time (Mayewski et al., 2004) and by the corresponding response of glaciers (Davis et al., 2009).
The Little Ice Age (LIA) and post-LIA Glacier Retreat
The last of the cooler periods in the Holocene (the Little Ice Age, LIA) occurred from 1400 to 1700 ad, with the greatest cooling over the extratropical Northern Hemisphere (Mann et al., 2009). Post-LIA climate change, glacier ice loss, and glacier retreat have been documented in most high-altitude (mountainous) and high-latitude (arctic) regions (Barry, 2006; Overpeck et al., 1997). It was shown by Zemp et al. (2006) that Alpine glaciers lost 35% of their area between 1850 and the 1970s and almost 50% between 1850 and 2000. An estimated two thirds of glacier ice were lost from Alpine glaciers during this period. Numerous studies focus on estimation of recent glacier changes in a regional context, for example in the Alps (Paul et al., 2004), the Andes (Vuille et al., 2008), and the Himalayas (Bolch et al., 2012).
Formation and Evolution of Glacial Lakes
Glacier ice loss and retreat (see the section “Climate Oscillations, Glaciation Cycle and Recent Glacier Retreat: An Overview”) are often accompanied by the formation and evolution of various subtypes of glacial lakes (Benn et al., 2012; Carrivick & Tweed, 2013; Heckmann et al., 2016; Hutchinson, 1957; Kalff, 2002; Komori, 2008). The subtypes include ice-dammed lakes, moraine-dammed lakes, and bedrock-dammed lakes. Emmer et al. (2015a) showed that, from a long-term perspective, moraine- and bedrock-dammed lakes evolve in relation to glacier retreat from the proglacial phase (direct contact with the mother glacier tongue), through the glacier-detached phase (no direct contact, some glaciers in the catchment), to the nonglacial phase (no glaciers in the catchment). In general, these phases have a relation to the hazardousness of a given lake—lake outburst floods. Lake outburst floods (see the section “Glacial Lake Outburst Floods”) are considered to be a specific evolutionary pattern that may occur never, once, or repeatedly during the evolution of the lake (Carrivick & Tweed, 2016; Duissaillant et al., 2010; Kropáček et al., 2015), while various subtypes of glacial lakes (see Figure 1) are susceptible to different causes and subsequent mechanisms of lake outbursts (see “Causes and Mechanisms of GLOFs”). Carrivick and Tweed (2016) showed that the majority of recorded GLOFs (70%) originated from ice-dammed lakes.
Ice-dammed lakes are all situated on glaciers (supraglacial lakes; see Figure 1A), within glaciers (englacial lakes), underneath glaciers (subglacial lakes), or at the margins of glaciers (Benn & Evans, 1998). Formation of ice-dammed lakes was shown to be related to changing climatic conditions, glacier ice loss (Carrivick & Tweed, 2013), and surge-type glacier activity. Surge-type glaciers are characterized by periodic large flow accelerations, usually accompanied by terminus advance (Harrison et al., 2015), possibly leading to the blocking of a valley and lake formation: that is, blocking of a main valley by a surging glacier situated in a side valley, or blocking of a side valley by a surging glacier situated in the main valley (Costa & Schuster, 1988). Repeated surging-induced formation of ice-dammed lakes and subsequent outburst flooding has been documented (Anacona et al., 2015a; Haemming et al., 2014).
Ice-dammed lakes vary in size from small ponds, with volumes up to 103 m3, to extremely large lakes with volumes larger than 1012 m3 (Hutchinson, 1957). Large ice-dammed lakes dominate in flat topographical conditions (especially high-latitude regions). Formation of small supraglacial lakes and their subsequent merging often precedes the formation of a glacial lake of another subtype (moraine- or bedrock-dammed lake) in suitable topographical conditions (see Frey et al., 2010). On the one hand, ice dams generally have short longevity, and ice-dammed lakes are often susceptible to producing outburst floods by releasing (part of) the retained water (Costa & Schuster, 1988; Korup & Tweed, 2007). Ice-dammed lakes are susceptible to both mechanisms of water release—dam overtopping and dam failure (see “Causes and Mechanisms of GLOFs”). On the other hand, with stable climatic conditions, large ice-dammed lakes may persist even for millennia (Clarke et al., 2004).
Moraine-dammed lakes are those retained by moraines (see Figure 1B), irrespective of the moraine type. Costa and Schuster (1988) showed that moraine-dammed lakes may form in various topographical positions relative to damming moraines. Moraine-dammed lakes are typically found in mountainous areas, where they can reach a volume of up to 109 m3 (Kalff, 2002). It was shown that moraine-dammed lakes typically form in the initial phases of glacier retreat, when glaciers are retreating from their maximum positions delimited by moraines, e.g., LIA-moraine-dammed lakes dammed by moraines formed during the Little Ice Age (see “The Little Ice Age (LIA) and Post-LIA Glacier Retreat”; Clague & Evans, 2000; Emmer et al., 2015a). In some cases, moraine-dammed lakes may also form due to the melting of buried (dead) ice, e.g., the formation and evolution of Lake Imja in the 1980s and 1990s (Watanabe et al., 1995). Moraine-dammed lakes are susceptible both to dam overtopping and dam failure (see “Causes and Mechanisms of GLOFs”) and the majority of GLOFs occur in the early (proglacial) phases of lake evolution, when lakes are exposed to calving processes and impact (displacement) waves (Clague & Evans, 2000; Emmer & Cochachin, 2013).
Bedrock-dammed glacial lakes (embedded lakes; see Figure 1C) occupy depressions excavated by glacial activity (Kalff, 2002). Bedrock dams are composed of solid rocks and are considered stable (Huggel, 2004; Mergili & Schneider, 2011). Therefore, dam overtopping is the only mechanism of lake outburst floods from this glacial lake subtype (see “Causes and Mechanisms of GLOFs”). In the observed post-LIA patterns of glacier retreat, the formation of moraine-dammed lakes dominates in the initial phases (retreat of the glaciers from their maximum extent, i.e., LIA moraines), while the formation of bedrock-dammed lakes dominates in later stages (LIA cirques located further upstream and bedrock overdeepenings; see Figure 2). Like moraine-dammed lakes, bedrock-dammed lakes are most susceptible to producing outburst floods in the young proglacial phase, when they are exposed to calving processes (Emmer et al., 2015a; see “Future Perspectives”).
Post-LIA glacier ice loss and retreat has been documented in the most of the mountain ranges worldwide (see “The Little Ice Age (LIA) and Post-LIA Glacier Retreat”) and this trend is expected to continue or even accelerate in the 21st century (Zemp et al., 2015). Glacier bed overdeepenings are modeled in order to identify locations that will host new, potentially hazardous lakes in future (Allen et al., 2016a; Haeberli et al., 2016a, 2016b; Linsbauer et al., 2016) in order to enhance GLOF risk management (see “Hazard Identification, Delimitation of Potentially Affected Areas and Elements at Risk”). Existing lakes change their susceptibility to outburst flood triggered by ice avalanche/calving processes in reaction to ongoing glacier retreat. The volume of water in them may also significantly change over time. Emmer et al. (2015a) showed that glacial lakes are generally most susceptible to producing an outburst flood at the end of their proglacial phase (Phase I) when they are exposed to calving processes and ice avalanches and lake volume is high, while they are less susceptible during the glacier-detached phase (Phase II), when susceptibility is decreased by fewer glaciers in the catchment and there is only residual susceptibility from other causes (e.g., impact waves from slope movements as a consequence of permafrost degradation), as expected in the stable nonglacial phase (Phase III; see Figure 3).
Glacial Lake Outburst Floods
Glacial lake outburst flood (GLOF) is a set phrase used to describe a sudden release of water (or parts thereof) retained in the glacial lake, irrespective of glacial lake subtype, cause, or mechanism (Benn & Evans, 1998; Clague & Evans, 2000; Clague & O’Connor, 2015). GLOFs are complex processes with various possible causes and mechanisms of origin (see “Causes and Mechanisms of GLOFs”) and have significant hydrological (see “Hydrological Significance”), geomorphological (see “Geomorphological Significance”), and possibly even societal impacts (see “Societal Impacts”).
Causes and Mechanisms of GLOFs
A GLOF may have diverse causes and subsequent mechanisms (how water is released). Specific causes are related to specific mechanisms and not all their combinations are realistic scenarios. Moreover, specific subtypes of glacial lakes (see “Formation and Evolution of Glacial Lakes”) are susceptible to specific causes and subsequent mechanisms of outburst floods. Numerous studies have investigated the causes of lake outburst floods for specific lake subtypes and regions (see Table 2); however, systematic investigation of the causes and mechanisms of GLOF, as well as database construction, are required (see Emmer et al., 2016a; Wirt et al., 2014) in order to better understand the complex processes and, in turn, provide more effective hazard and risk management (see “GLOF Risk Management”).
Table 2. Examples of Studies Focusing on Analysis of the Causes and Mechanisms of Glacial Lake Outburst Floods (based partly on Emmer et al., 2016a)
Anacona et al. (2015a)
Chilean and Argentinean Andes
Clague and Evans (2000)
Emmer and Cochachin (2013)
Cordillera Blanca (Peru), Himalaya, North American Cordillera
Ding and Liu (1992)
Harrison et al. (2006)
Ives et al. (2010)
Hindu Kush-Himalaya region
O’Connor et al. (2001)
North American Cordillera
Richard and Gay (2004)
Europe (GLACIORISK project)
Walder and Costa (1996)
Xu et al. (2015)
Notes: MDL= moraine-dammed lakes; BDL= bedrock-dammed lakes; IDL= ice-dammed lakes.
* While great attention is paid to moraine-dammed and ice-dammed lakes, bedrock-dammed lakes are often neglected.
Based on a literature review (Clague & Evans, 2000; Costa & Schuster, 1988; Emmer & Cochachin, 2013; Grabs & Hanisch, 1993; Mergili & Schneider, 2011; Richardson & Reynolds, 2000a; Zapata, 2002), the following direct causes of glacial lake outburst floods (C1–C7; see Table 3 and Figure 4) were documented:
Rapid slope movement into the lake(C2)
Cascading processes (flood from a lake situated upstream)(C4)
Melting of ice incorporated in dam/forming the dam (including volcanic activity-triggered jökulhlaups)(C6)
Blocking of subsurface outflow tunnels (applies only to lakes without surface outflow or lakes with a combination of surface and subsurface outflow)(C7)
Long-term dam degradation.
Table 3. Causes (C4) to (C7) and Relevant Specific Glacial Lake Subtypes
Relevant glacial lake subtype
Melting of ice incorporated in dam/forming the dam (C5)
IDL, Ice-cored MDL
Blocking of subsurface outflow tunnels (C6)
IDL, MDL with subsurface outflow tunnels
Long-term dam degradation (C7)
Note: MDL = moraine-dammed lakes; IDL= ice-dammed lakes.
In terms of mechanisms of GLOFs (how water is released; see Figure 5), two are distinguished:
Dam overtopping by a displacement wave (major part of released water flows over the dam without significant damage to the dam itself). Dam overtopping is a possible mechanism for all glacial lake subtypes and the only possible mechanism for bedrock-dammed lakes.(M2)
Dam failure (a major part of the water is released by failure of the dam, including: direct rupture of the dam, incision and breaching, and piping and seepage). Dam failure is possible only for moraine- and ice-dammed lakes.
Obviously, not all direct causes (C1–C7) are tied to both mechanisms (M1–M2) of GLOFs (see Table 4). Moreover, different mechanisms involve different glacial lake subtypes. While dam overtopping is the only possible GLOF mechanism for bedrock-dammed lakes, dam failure is possible for only moraine- and ice-dammed lakes. In some specific cases, dam overtopping is followed by dam failure (dam overtopping-induced dam failure; Kershaw et al., 2005). An example is the two-phase outburst flood from the moraine-dammed Queen Bess Lake in British Columbia, Canada. An ice avalanche into the lake caused dam overtopping (first phase) and increased discharge later on caused erosion of the surface outflow channel, its incision, and consequently dam failure (second phase). The majority of the flood volume was released during the overtopping phase (Kershaw et al., 2005).
Table 4. Matrix of Potential Causes and Possible Mechanisms of Glacial Lake Outburst Floods
Rapid slope movement into the lake (C1)
Heavy rainfall/snowmelt (C3)
Melting of ice incorporated in/forming the dam (C4)
R, B, P
Cascading processes (C5)
Blocking of subsurface outflow tunnels (C6)
R, B, P
Long term dam degradation (C7)
R, B, P
Notes: Dam overtopping: N/A = nonrealistic scenario for the given cause; D = dam overtopping by displacement wave(s); O = dam overtopping by new lake outflow(s) (not in the form of displacement wave). Dam failure: R = direct rupture; B = incision and breaching; P = piping and seepage.
Rapid Slope Movement into the Lake (C1)
When they hit the lake, various types of fast slope movements (slides, falls, avalanches, and flows; see Figure 6) may cause a lake outburst flood. Fast slope movement into the lake produces displacement wave(s) (Richardson & Reynolds, 2000a) which, in turn, may: overtop the dam (all glacial lake subtypes) or cause direct rupture of the dam (moraine and ice dams). Various types of fast slope movements (especially ice avalanches) were shown to be the most frequent documented cause of GLOFs from moraine- and bedrock-dammed lakes in the Himalayas and Andes (Anacona et al., 2015a; Emmer & Cochachin, 2013; Richardson & Reynolds, 2000a).
By analyzing 2002 GLOFs from Lake Safuna Alta, Cordillera Blanca, Peru, Hubbard et al. (2005) showed that displacement waves may overflow the dam despite tens of meters of dam freeboard (80 m in this case). Numerous examples of rapid slope movements causing GLOFs have been documented from all around the world (Emmer & Cochachin, 2013). In the face of climate change (see “Recent Glacier Retreat and Formation of Lakes”), slope movements are considered to have increased in high mountain regions (see Dietrich & Krautblatter, 2016; Haeberli et al., 2016a; Huggel et al., 2012; Stoffel & Huggel, 2012). These are slope movements directly related to glacier ice loss—ice avalanches and ice/rock avalanches (see Alean, 1985; Richardson & Reynolds, 2000a; see Figure 3A); diverse types of slope movements associated with permafrost degradation (Haeberli, 2013; Haeberli et al., 2016a); landslides in recently deglaciated moraine slopes that have lost the support of the glacier, which subsequently downwasted and retreated (Klimeš et al., 2016; see Figure 3B); and debutressing-induced rockfall/rockslide (Cossart et al., 2008; Evans & Clague, 1994; McColl, 2012).
Heavy Rainfall/Snowmelt (C2)
Increased water inflow into a lake caused by heavy rainfall or intense snowmelt (or a combination thereof) causes increased discharge (outflow) from the lake. In the case of moraine-dammed lakes (and possibly also ice-dammed lakes), increased discharge may lead to increased erosion and incision of the outflow channel into the dam body, which in turn may lead to increased discharge and dam failure (positive feedback; Yamada, 1998). Several GLOFs from British Columbia in Canada and the Cascade Range in the United States are attributed to heavy rainfall, such as the GLOF from Tide Lake in the 1920s (Clague & Evans, 2000) and that from the lake beneath Dellier glacier (O’Connor et al., 2001). The 2013 GLOF from Lake Chorabari, Garhwal Himalaya, India (Kedarnath disaster) was also caused by heavy rainfall (Allen et al., 2016b; Dobhal et al., 2013; see also “Societal Impacts”). Heavy rainfall may also act as an indirect trigger of GLOFs when rainfall triggers slope movement into the lake (Emmer & Cochachin, 2013).
Cascading Processes (Flood from a Lake Situated Upstream; C3)
Within individual valleys, glacial lakes are often grouped into cascading systems (Hutchinson, 1957; Kalff, 2002). GLOFs originating in upstream lakes may, in turn, cause GLOFs in lakes downstream. Downstream lakes may amplify the intensity and magnitude of a flood further downstream (increase the flood volume by releasing retained water), or they may mitigate the intensity and magnitude of the flood (reduce the flood volume by retention capacity; see Emmer & Juřicová, in print). These complex chain process interactions, which are predicted to increase their frequency in future, have recently attracted significant scientific attention (Haeberli et al., 2016b; Mergili et al., forthcoming; Westoby et al., 2014; Worni et al., 2014).
The direct mechanism of earthquake-triggered lake outburst floods is dam rupture (moraine or ice dam), or earthquake-induced piping and subsequent dam failure (moraine dams; Lliboutry et al., 1977). A limited number of earthquake-triggered lake outburst floods are documented in the literature (Emmer & Cochachin, 2013). A well-known example of an earthquake-triggered lake outburst flood is the GLOF from Lake Safuna Alta, Cordillera Blanca, Peru. A heavy earthquake on May 31, 1970, changed the internal structure of the dam and piping occurred (Lliboutry et al., 1977). The lake water level decreased by 38 m, with release of a major part of the 4.9 ∙ 106 m3 of water retained in the lake at that time. Another example is the Late Pleistocene earthquake-triggered moraine dam failure and outburst flood from Lake Zurich, Switzerland; however, in this case, it is not clear whether the lake outburst flood was caused directly by an earthquake or indirectly by earthquake-triggered slope movement(s) into the lake (for more details, see Strasser et al., 2003). Besides earthquake-triggered slope movements into the lake, another possibility for indirect earthquake-triggered lake outburst floods is earthquake-induced blockage of outflow tunnels, subsequent water level increase, and failure due to the increased hydrostatic pressure or overtopping. The Gorkha earthquake in Nepal in 2015 (M = 7.8), however, documented that not every strong earthquake in high mountain areas necessarily leads to lake outburst floods (Kargel et al., 2016). Earthquake-triggered GLOFs are, actually, quite rare compared to GLOFs with other documented triggers (see Emmer & Cochachin, 2013).
Melting of Ice Incorporated in Dam/Forming the Dam (Including Volcanic Activity-Triggered Jökulhlaups; C5)
The C5 trigger occurs in ice-dammed lakes, possibly in moraine-dammed lakes if the dam contains an ice lens (so called “buried” or “dead” ice; e.g., Kruger & Kjaer, 2000; Schomacker, 2008), and in lakes dammed in an arid permafrost environment (e.g., lakes dammed by rock glaciers). Permafrost thawing and degradation may, therefore, play an important role in lake evolution and also in the occurrence of outburst flood due to permafrost degradation-induced slope movements (Haeberli, 2013; Haeberli et al., 2016a; see “Rapid Slope Movement into the Lake (C1)”). Walder and Costa (1996) showed that flooding from ice-dammed lakes is associated with drainage through a tunnel incised into the basal ice, ice-marginal drainage with mechanical failure of part of the ice dam, or a combination of the two. A specific type of outburst flood related to volcanic activity is called jökulhlaup (volcanic activity-induced lake outburst flood, see Table 1; Bjornsson, 2001; Tweed & Russel, 1999). In the case of a lake dammed by an ice-cored moraine, the melting of the ice cores may lead to structural disintegration of the dam body and piping, or dam subsidence, with formation of new surface outflow(s), and incision and breaching (see Richardson & Reynolds, 2000b).
Blocking of Subsurface Outflow Tunnels (C6)
Emmer and Cochachin (2013) showed that glacial lakes with subsurface outflow (only possible for moraine- or ice-dammed lakes) are susceptible to blocking of the outflow tunnels by: (a) sediment brought into the lake by its tributaries, (b) slope movements (e.g., slopes on the inner slopes of moraine dams), (c) freezing of outflow channels (O’Connor et al., 2001), and (d) change in the internal structure of the dam caused by an earthquake (Lliboutry et al., 1977). If the subsurface outflow tunnel(s) are blocked, the level of the lake starts to rise, which may, in turn, lead to dam rupture triggered by increased hydrostatic pressure (Richardson & Reynolds, 2000a), or dam overtopping, incision, and failure. An example of failure caused by blocking of subsurface outflow tunnels is the moraine dam failure event at Lake Zhangzhanbo in Tibet on July 11, 1981 (Ding & Liu, 1992; Yamada, 1998).
Long-Term Dam Degradation (C7)
Spontaneous moraine (icy) dam failure without any evident (dynamic) cause may be explained as a co-action of long-term degrading processes (i.e., dam self-destruction; Yamada, 1998; Emmer & Cochachin, 2013), such as successive changes in the internal structure of the dam leading to piping and failure or hydrostatic pressure. Several GLOFs from the Hindu-Kush Himalaya region have been attributed to this cause (Ives et al., 2010; Yamada, 1998), such as the GLOF from Lake Lugge Tsho, Bhutan Himalaya, in 1994, which was caused by increased hydrostatic pressure induced by basal ice melting that resulted in deepening of the lake (Watanabe & Rothacher, 1996).
GLOFs represent extreme hydrological processes in terms of flood volume (V), peak discharge (Qmax), and the ratio of peak discharge to mean flow rate (Clague & O’Connor, 2015). The flood volume has exceeded thousands of cubic kilometers in reconstructed paleo-GLOFs, such as the 3,000 km3 outburst of the ice-dammed Lake Vitim in Siberia (Margold et al., 2011). Floods with volumes on the order of several km3 have recently occurred, such as the 3.2 km3 jökulhlaup from the subglacial Lake Grímsvötn in Iceland in 1997 (Gudmundsson et al., 1997), or the 0.23 km3 outburst from the moraine-dammed Laguna del Cerro Largo (Chile) in 1989 (Hauser, 1993), which is considered to be the largest documented GLOF originating from a moraine-dammed lake (Clague & Evans, 2000).
In terms of peak discharge, documented/reconstructed GLOFs are ranked among the world’s largest floods (O’Connor & Costa, 2004). Examples are Late Pleistocene GLOFs from ice-dammed lakes, such as the GLOF from Lake Kuray (Altai, Russia), with a peak discharge of 1.8 · 107 m3 s−1 (Baker et al., 1993), or the GLOF from Lake Missoula (United States), with a peak discharge of 1.7 · 107 m3 s−1 (O’Connor & Baker, 1992). An outburst flood from Lake Agassiz with a discharge of 1.2 · 106 m3 s−1 (Smith & Fischer, 1993) is considered to be one of the largest floods in the Holocene (O’Connor & Costa, 2004). Peak discharges from recent (post-LIA) GLOFs have been documented up to 105 m3 s−1 in some cases (Walder & O’Connor, 1997) and up to 3 · 105 m3 s−1 in the case of recent jökulhlaups (e.g., Katla jökulhlaup in 1918; Tomasson, 1996). Peak discharge is often estimated using lake-volume-based empirical equations (Costa, 1985; Huggel et al., 2004); it is, however, also strongly influenced by the mechanism of the outburst flood (Haeberli, 1983), the topography, and the distance from the lake (Costa, 1985; Schwanghart et al., 2016), which directly influences downstream hazard of GLOF (see “GLOF Risk Management”).
GLOFs are also characterized by an extremely high ratio of peak discharge to mean flow rate (Clague & Evans, 2000; Smith et al., 2014), which may be many times greater than the peak discharge of “normal” rainfall/snowmelt-induced floods. Cenderelli and Wohl (2001) showed that the peak discharges of lake outburst floods in the Mt. Everest region were up to 60 times greater than seasonal high-flow floods. Due to the extreme peak discharges, GLOFs are also characterized by extremely high erosion and transportation potential (see “Geomorphological Significance”). Lake outburst floods may, therefore, easily transform into flow-type movement, such as debris flows (O’Connor et al., 2001) with a density of approximately 1.5 t/m3 (Yamada, 1998) and an extraordinary damage potential (see “Societal Impacts”).
Possible Impacts of Major GLOFs on the Circulation of the Oceans and Global Climate
Major paleolake outburst floods from ice-dammed lakes into oceans are considered able to change circulation patterns and, in turn, influence the global climate (Barber et al., 1999; Bond et al., 1992; Clarke et al., 2004; Hemming, 2004). It has been shown that a sudden release of an extremely large amount of cold freshwater into the ocean (a so-called Heinrich event; Hemming, 2004) correlated well with global-scale climate changes in the Late Pleistocene and Holocene. A well-known example is the major outburst flood from the ice-dammed Lake Agassiz into the Labrador Sea, 8,200 BP (Bauer et al., 2004; Clarke et al., 2004), which reduced the salinity of the surface layer of the northern Atlantic Ocean and subsequently altered ocean circulation. This event is considered to have initiated the most abrupt cold event in the Holocene (Barber et al., 1999; Clark et al., 2001; Teller et al., 2002).
Reflecting hydrological significance of GLOFs, it was shown by Evans and Clague (1994), Costa and O’Connor (1995), Richardson (2010), and Clague et al. (2012) that GLOFs are among the most significant geomorphological processes in high mountain areas during periods of glacier ice loss. Geomorphological impacts are directly tied to the stream power of floods (Benito, 1997; Desloges & Church, 1992; Krapesch et al., 2011). Baker et al. (1993) estimated that the stream power per unit area of the Late Pleistocene flood in Altay, Russia, was 105 W m−2 for subcritical flow and 106 W/m2 for supercritical flow. Cenderelli and Wohl (2003) estimated that the stream power of the recent Himalayan GLOFs was up to 5 · 104 W m−2. GLOFs, therefore, have significant potential to influence erosion-accumulation interactions and sediment dynamics on various spatial scales (Cenderelli & Wohl, 2003; Morche & Schmidt, 2012). Late Pleistocene outburst floods from ice-dammed lakes (such as Lake Missoula; Baker & Bunker, 1985) have had significant continental-scale geomorphic impacts (Mangerud et al., 2004), which are identifiable in the field even after tens of thousands of years (Baker et al., 1993).
Recent (post-LIA) GLOFs are characterized by a reach of up to hundreds of kilometers in some cases, with rapidly decreasing geomorphological impacts with increasing distance from the lake and strong attenuation of peak discharge (Anacona et al., 2015b; Cenderelli & Wohl, 2003; Hewitt, 2016; Richardson & Reynolds, 2000a). Erosional symptoms and landforms related to GLOFs are typically bank and depth erosion of the stream/river channel, meander shift, and, in some cases, replacement of existing channels and formation of new ones (accompanied by the formation of abandoned channels) or formation of erosional terraces (Robitaille & Dubois, 1995; Thorndycraft et al., 2016; see Figure 7). Failed moraine dams are also considered to be specific landforms associated with GLOFs (Clague & Evans, 2000).
Richardson and Reynolds (2000a) showed that recent GLOFs are capable of transporting boulders with diameters of up to several meters and an estimated mass of 200 tons. Entrainment in the order of 108 m3 has been documented, as in the 1996 Grimsvötn (Iceland) GLOF, while the mean specific sediment yield may reach 107 t/km2/yr for a short time (Korup, 2012; Stefánsdottir & Gíslason, 2005). Korup (2012) further showed that extreme specific sediment yields (> 107 t/km2/yr) in mountain environments are typically linked to extreme events, such as volcanic eruptions, mass movements, or lake outburst floods. Accumulational landforms vary from interchannel sand bars and bank boulder accumulation to outwash fans covering large piedmont areas (Bernard et al., 2006; Robitaille & Dubois, 1995; see Figure 8). By analyzing the 2012 GLOF from lake No. 513 (Peru), Vilímek et al. (2015) showed that the geomorphological consequences of GLOFs vary significantly across the longitudinal valley profile, reflecting general topographical conditions and the amount and grain size of sediment available for entrainment.
Carrivick and Tweed (2016) compiled a world inventory of the societal impacts (deaths and property and infrastructure destruction and disruption) of documented GLOFs (1,348 individual events from 332 sites). It was shown that, for 36% of the sites, a GLOF had some societal effects, and the overall number of fatalities exceed 12,000, of which most were in South America (Peru) and Central Asia (Nepal and India). It was further shown that high-magnitude GLOFs are quite rare, but may have disastrous consequences if they occur in settled areas. Two examples of significant post-LIA GLOFs are the Lake Palcacocha moraine dam failure in 1941 (Cordillera Blanca, Peru) and the Lake Chorabari moraine dam failure (Kedarnath GLOF disaster) in 2013 (Garhwal Himalaya, India). According to Carrivick and Tweed (2016), these two events are responsible for 88% of the fatalities caused by documented GLOFs.
Lake Palcacocha (December 13, 1941)
Lake Palcacocha (9°23′52′′ S, 77°22′52′′ W) is situated at the head of the Cojup valley, beneath the southern slopes of the Palcaraju massif (6,274 m a.s.l.) and western slopes of the Pucaranra massif (6,156 m a.s.l.), Cordillera Blanca, Peru (see Figure 9). Dam failure occurred at 6:45 a.m. on December 13, 1941 (Zapata, 2002). Oppenheim (1946) mentioned two alternative causes: seepage-induced dam failure, and an ice avalanche into the lake initiating breaching; however, no direct evidence for either of these potential causes was recorded. The pre-failure lake water level elevation was 4,610 m a.s.l., which decreased by 47 m during the event (i.e., 47 m breach depth). Material eroded from the dam formed a 300-m wide and 1,080-m long fan (see Figure 9B and 9C).
The volume of released water was estimated to be between 8 ∙ 106 m3 (Evans & Clague, 1994) and 10 ∙ 106 m3 (Vilímek et al., 2005). The outburst flood following the failure of the Lake Palcacocha dam subsequently caused failure of the dam on landslide-dammed Lake Yircacocha situated in the valley 8.2 km downstream, increasing the overall flood volume by approximately 2.0 to 3.0 ∙ 106 m3. The resulting flood affected the valley floor of Cojup stream over a width of up to 200 m (topographically limited in the upper parts) and up to 500 m in the lower part (alluvial fan on the confluence with Santa River) and transported an overall volume of 4 ∙ 106 m3 of material (Zapata, 2002). The event destroyed almost one third of the city of Huaráz (23 km away, elevation difference 1,550 m, mean slope of the valley 3.9°), claimed thousands of fatalities (Oppenheim, 1946), and is considered to be one of the worst natural dam failures ever documented. After the moraine dam failure, Lake Palcacocha was replaced by a small (about 0.5 ∙ 106 m3) remnant lake dammed by a basal moraine. This lake has ubdergone rapid growth due to glacier retreat. Its current volume is greater than it had been before 1941 (UGRH, 2015), putting the lake’s safety into question (see Somos-Valenzuela et al., 2016).
Lake Chorabari (June 16–17, 2013)
Lake Chorabari (30°44'51" N, 79°03'39" W) was situated in the Kedarnath (Mandakini) valley, Garhwal Himalaya, India, beneath the southern slopes of the Kedarnath massif (6,940 m a.s.l.). A seasonal lake without any surface outflow was dammed by the distal face of the right lateral moraine of the Chorabari glacier, situated 3,850 m a.s.l. Moraine dam failure occurred on June 17, 2013, and was caused by enhanced spring snowmelt combined with heavy rainfall (Dobhal et al., 2013; Ray et al., 2015). It was shown that the cumulative rainfall was more than 390 mm over a 7-day period (Allen et al., 2016b). The heavy rainfall claimed about 5,000 fatalities in Uttarakhand, most of which were caused by the Lake Chorabari event (Ray et al., 2015).
The volume of water released from Lake Chorabari was estimated to be 0.43 ∙ 106 m3. The resulting flood wave caused intense entrainment of loose sediment, transforming the outburst flood into debris flow movement (Das et al., 2015), which traveled downstream to the village of Kedarnath, situated 1,500 m from the lake (300 m vertical difference). Besides the numerous fatalities (Das et al., 2015), the event had significant impacts in the village of Kedarnath, an important holy site. The northwest part of the village was directly affected by the GLOF-induced debris flow and suffered the heaviest damage; 138 of the 259 structures were obliterated and 56 structures were damaged. Only one quarter of the village was not affected. In addition, indirect economic losses due to decreased tourism were registered.
GLOF Risk Management
In the basic concept of natural hazards and risks, the risk of a GLOF is explained as a result of: hazard of GLOF (probability of the occurrence of the flood described by specific characteristics, such as flood volume, peak discharge, spatial extent, etc.), and the vulnerability of elements in potentially affected areas. This concept has been modified in various ways in relation to GLOFs or GLOF-induced debris flows, by Ciurean et al. (2016), Emmer et al. (2014), Fuchs (2008), Hegglin and Huggel (2008), Huggel et al. (2004), Richardson (2010), and Shrestha (2010). Effective GLOF risk management includes two general steps: hazard identification and delimitation of potentially affected areas, including identification of elements at risk; and risk minimization by hazard reduction and vulnerability reduction.
Hazard Identification and Delimitation of Potentially Affected Areas and Elements at Risk
The first step in GLOF risk management is reliable identification of hazardous lakes, i.e., lakes susceptible to producing lake outburst floods (Haeberli & Whiteman, 2015; Kääb et al., 2005). Unlike “classical” hydrometeorologically induced floods, GLOFs are rarely repeated events and their occurrence usually cannot be derived from return periods; furthermore, the hazard changes over time, reflecting the evolution of a given lake (see “Future Perspectives”). To identify hazardous lakes, a number of predominantly remotely sensed data-based methods were developed for diverse environments. Reflecting the different dominant causes of GLOFs in different environments (Emmer & Cochachin, 2013), regionally based methods seem to provide the most plausible solution. Examples are methods designed for the Hindu Kush-Himalaya region (Ives et al., 2010; Rounce et al., 2016; Wang et al., 2011; Wang & Jiao, 2015), Tien Shan (Bolch et al., 2011; Zaginaev et al., 2016), Pamir (Gruber & Mergili, 2013; Mergili & Schneider, 2011), the Cordillera Blanca, Peru (Emmer & Vilímek, 2014; Reynolds, 2003), British Columbia (McKillop & Clague, 2007a,b), and the Swiss Alps (Huggel et al., 2002, 2004). All the methods are based on assessment of selected characteristics indicating increased likelihood of lake outburst floods (see Emmer & Vilímek, 2013, 2014), which might be grouped according to: dam characteristics (e.g., dam type, dam freeboard, dam geometry), lake characteristics (e.g., lake area, lake volume), and characteristics of lake surrounding (e.g., characteristics of the glaciers and characteristics of slopes facing the lake, such as presence and condition of permafrost).
Delimitation of potentially affected areas and subsequent identification of elements at risk are usually based on various modeling approaches, use of digital elevation models, and predefined scenarios of triggering events (e.g., slope movement of a given volume into the lake), as well as validation on previous GLOFs (Anacona et al., 2015b; Carey et al., 2012; Kropáček et al., 2015; Pitman et al., 2013; Somos-Valenzuela et al., 2016; Westoby et al., 2015; Worni et al., 2014; Zhang & Liu, 2015). Once hazardous lakes are identified and potentially affected areas are delimited, elements at risk are revealed. Naturally, these approaches usually have a degree of uncertainty as well as potential drawbacks (Mergili, 2016; Westoby et al., 2014); however, they prove to be useful tools in GLOF risk management (Anacona et al., 2015b; Huggel et al., 2004; Kääb et al., 2005). Consequently, GLOF risk mitigation is generally feasible through the application of hazard and vulnerability reduction.
Hazard and Vulnerability Reduction
GLOF hazard and vulnerability reduction (risk mitigation) is a highly challenging task, because GLOFs may have exceptional peak discharge and stream power (see “Hydrological Significance”), as well as erosion and transport potential (see “Geomorphological Significance”). Diverse structural GLOF hazard mitigation measures have been applied at selected lakes around the world: in the Swiss Alps (Haeberli et al., 2001; Lichtenhahn, 1971), Scandinavia (Grabs & Hanisch, 1993), Hindu Kush-Himalaya region (Ives, 1986; Kattelmann, 2003; Richardson, 2010), and the Cordillera Blanca, Peru (Carey, 2005; Emmer et al., 2016b; Portocarrero, 2014; Reynolds et al., 1998). Measures aimed at the prevention or mitigation of the magnitude of the flood (dam remediation; e.g., artificial dams, tunnels, open cuts, concrete outflows; see Emmer et al., 2016b) and measures aimed at diverting the flood wave from vulnerable areas (downstream flood-protection measures, such as flood-protection walls; see Figure 10A) are generally distinguished. Vulnerability in areas potentially affected by GLOFs (or GLOF-induced debris flows) is reduced by diverse measures, which are generally divided into structural measures (e.g., construction improvements increasing the resilience of elements at risk) and nonstructural measures, such as early warning systems (see Figure 10B), information campaigns, insurance, etc. (Ciurean et al., 2016; Fuchs, 2008; Hegglin & Huggel, 2008; Shrestha, 2010). The increased vulnerability of communities in high mountains areas (e.g., Andes, Hindu Kush-Himalaya region) is often linked to low adaptive capacity (Berkes, 2007; Carey et al., 2015; Cutter et al., 2008; Hewitt, 2016).
Conclusions and Hindsight
Glacier ice loss and retreat driven by climate change have become a broadly studied topic in different environments throughout the world because glacier retreat is frequently accompanied by the formation and evolution of lakes, most commonly glacial lakes (ice-dammed lakes, moraine-dammed lakes, and bedrock-dammed lakes). A significant number of glacial lakes have formed within areas that have become deglaciated since the end of the Little Ice Age—the period of the last significant glacier advance. Such lakes are commonly dynamically evolving entities, generally with relatively short longevity (Costa & Schuster, 1988). GLOFs are a specific evolutionary pattern of a glacial lake; they involve the sudden release of (a part of) the retained water from a lake, irrespective of the cause, mechanism, and glacial lake subtype involved (Korup & Tweed, 2007).
GLOFs are highly complex phenomena, which may be triggered by diverse processes (causes): (C1) rapid slope movement into the lake; (C2) heavy rainfall/snowmelt; (C3) cascading processes (flood from a lake situated upstream); (C4) earthquake; (C5) melting of ice incorporated in the dam/forming the dam (including volcanic activity-triggered jökulhlaups); (C6) blocking of subsurface outflow tunnels (only in the case of lakes with subsurface outflow); (C7) long-term dam degradation (Clague & Evans, 2000). Causes (C1) and (C5) are both directly or indirectly linked to glacier retreat. Causal processes are potentially followed by two diverse mechanisms of water release (lake outburst flood)—dam overtopping by a displacement wave (where the majority of the released water flows over the dam without damaging it) and dam failure (where the majority of the water is released by failure of the dam, including direct rupture of the dam, incision and breaching, piping and seepage). Specific causes are linked to specific mechanisms, and, moreover, specific glacial lake subtypes, and even triggering events of relatively small magnitudes may lead to significant and destructive processes.
GLOFs are characterized by hydrological significance—peak discharges of GLOFs can be far higher than those of hydrometeorologically induced floods, resulting in exceptional erosion and transport potentials; therefore, they often transform into flow-type movement (e.g., debris flow) if erodible material is available. The documented major GLOFs also caused significant geomorphological changes. Due to these characteristics, GLOFs clearly may also have catastrophic societal impacts, if they affect settled areas. Fatal GLOFs have been documented in the Andes and in the Hindu Kush-Himalaya region (Carrivick & Tweed, 2016). With ongoing climate change, the risk of GLOFs has been predicted to increase, due to the formation and evolution of different subtypes of new, potentially hazardous, glacial lakes, often hand in hand with both the increasing vulnerability of the elements at risk and low adaptive capacity.
The author thanks the Grant Agency of Charles University (GAUK project No. 70 613 and GAUK project No. 730 216), the Mobility Fund of Charles University, the AKTION Austria–Czech Republic project “Currently forming glacial lakes: potentially hazardous entities in deglaciating high mountains,” provided by the OeAD-GmbH and the Ministry of Education, Youth and Sports of the Czech Republic within the framework of the National Sustainability Programme I (NPU I), and Grant No. LO1415 for the continuous long-term support of research on glacial lake outburst floods.
- Alean, J. (1985). Ice avalanches—Some empirical information about their formation and reach. Journal of Glaciology, 31(109), 324–333.
- Allen, S. K., Linsbauer, A., Randhawa, S. S., Huggel, C., Rana, P., & Kumari, A. (2016a). Glacial lake outburst flood risk in Himachal Pradesh, India: An integrative and anticipatory approach considering current and future threats. Natural Hazards, 84(3), 1741–1763.
- Allen, S. K., Rastner, P., Arora, M., Huggel, C., & Stoffel, M. (2016b). Lake outburst and debris flow disaster at Kedarnath, June 2013: Hydrometeorological triggering and topographic predisposition. Landslides, 13(6), 1479–1791.
- Anacona, P. I., Mackintosh, A., & Norton, K. P. (2015a). Hazardous processes and events from glacier and permafrost areas: Lessons from the Chilean and Argentinean Andes. Earth Surface Processes and Landforms, 40(1), 2–21.
- Anacona, P. I., Mackintosh, A., & Norton, K. (2015b). Reconstruction of a glacial lake outburst flood (GLOF) in the Engano Valley, Chilean Patagonia: Lessons for GLOF risk management. Science of the Total Environment, 527, 1–11.
- Baker, V. R., Benito, G., & Rudoy, A. N. (1993). Paleohydrology of Late Pleistocene superflooding, Altay Mountains, Siberia. Science, 259, 348–350.
- Baker. V. R., & Bunker, R. C. (1985). Cataclysmic Late Pleistocene flooding from glacial Lake Missoula—A review. Quaternary Science Reviews, 4(1), 1–41.
- Barber, D. C., Dyke, A., Hillaire-Marcel, C., Jennings, A. E., Andrews, J. T., Kerwin, M. W., . . . Gagnon, J. M. (1999). Forcing of the cold event of 8,200 years ago by catastrophic drainage of Laurentide lakes. Nature, 400(6742), 344–348.
- Barry, R. G. (2006). The status of research on glaciers and global glacier recession: A review. Progress in Physical Geography, 30(3), 285–306.
- Bauer, E., Ganopolski, A., & Montoya, M. (2004). Simulation of the cold climate event 8200 years ago by meltwater outburst from Lake Agassiz. Paleocenography, 19(3), PA3014.
- Benito, G. (1997). Energy expenditure and geomorphic work of the cataclysmic Missoula flooding in the Columbia River Gorge, USA. Earth Surface Processes and Landforms, 22(5), 457–472.
- Benn, D., & Evans, D. J. A. (1998). Glaciers and glaciation. London: Hodder Arnold Publication.
- Benn, D. I., Bolch, T., Hands, K., Gulley, J., Luckmanm A., Nicholson, L. I., . . . Wiseman, S. (2012). Response of debris-covered glaciers in the Mount Everest region to recent warming, and implications for outburst flood hazards. Earth-Science Reviews, 114(1–2), 156–174.
- Berkes, F. (2007). Understanding uncertainty and reducing vulnerability: Lessons from resilience thinking. Natural Hazards, 41(2), 283–295.
- Bernard, P. L., Owen, L. A., & Finkel, R. C. (2006). Quaternary fans and terraces in the Khumbu Himal south of Mount Everest: Their characteristics, age and formation. Journal of the Geological Society, 163, 383–399.
- Bintanja, R., van de Wal, R. S. W., & Oerlemans, J. (2005). Modelled atmospheric temperatures and global sea levels over the past million years. Nature, 437(7055), 125–128.
- Bjornsson, H. (2001). Subglacial lakes and jokulhlaups in Iceland. Global and Planetary Change, 35(3–4), 255–271.
- Bolch, T., Kulkarni, A., Kääb, A., Huggel, C., Paul, F., Cogley, J. G., . . . Stoffel, M. (2012). The state and fate of Himalayan glaciers. Science, 336(6079), 310–314.
- Bolch, T., Peters, J., Yegorov, A., Pradhan, B., Buchroithner, M., & Blagoveshchensky, V. (2011). Identiﬁcation of potentially dangerous glacial lakes in the northern Tien Shan. Natural Hazards, 59(3), 1691–1714.
- Bond, G., Heinrich, H., Broecker, W., Labeyrie, L., McManus, J., Andrews, J., . . . Ivy, S. (1992). Evidence for massive discharges of icebergs into the North-Atlantic Ocean during the last glacial period. Nature, 360(6401), 245–249.
- Carey, M. (2005). Living and dying with glaciers: People’s historical vulnerability to avalanches and outburst floods in Peru. Global and Planetary Change, 47(2–4), 122–134.
- Carey, M., Huggel, C., Bury, J., Portocarrero, C., & Haeberli, W. (2012). An integrated socio-environmental framework for glacial hazard management and climate change adaptation: Lessons from Lake 513, Cordillera Blanca, Peru. Climatic Change, 112(3–4), 733–767.
- Carey, M., McDowell, G., Huggel, C., Jackson, J., Portocarrero, C., Reynolds, J. M., & Vicuña, L. (2015). Integrated approaches to adaptation and disaster risk reduction in dynamic socio-cryospheric systems. In W. Haeberli & C. Whiteman (Eds.), Snow and ice-related hazards, risks, and disasters (pp. 219–261). Amsterdam, The Netherlands: Elsevier.
- Carrivick, J. L., & Tweed, F. S. (2013). Proglacial lakes: Character, behaviour and geological importance. Quaternary Science Reviews, 78, 34–52.
- Carrivick, J. L., & Tweed, F.S. (2016). A global assessment of the societal impacts of glacier outburst floods. Global and Planetary Change, 144, 1–16.
- Cenderelli, D. A., & Wohl, E. E. (2001). Peak discharge estimates of glacial-lake outburst floods and “normal” climatic floods in the Mount Everest region, Nepal. Geomorphology, 40(1–2), 57–90.
- Cenderelli, D. A., & Wohl, E. E. (2003). Flow hydraulics and geomorphic effects of glacial-lake outburst floods in the Mount Everest region, Nepal. Earth Surface Processes and Landforms, 28(4), 385–407.
- Ciurean, R. L., Hussin, H., van Westenm C. J., Jaboyedoff, M., Nicolet, P., Chen, L., . . . Glade, T. (2016). Multi-scale debris flow vulnerability assessment and direct loss estimation of buildings in the Eastern Italian Alps. Natural Hazards, 85(2), 939–957.
- Clague, J. J., & Evans, S. G. (2000). A review of catastrophic drainage of moraine-dammed lakes in British Columbia. Quaternary Science Reviews, 19(17–18), 1763–1783.
- Clague, J. J., Huggel, C., Korup, O., & McGuire, B. (2012) Climate change and hazardous processes in high mountains. Revista de la Asociación Geológica Argentina, 69(3), 328–338.
- Clague, J. J., & O’Connor, J. E. (2015). Glacier-related outburst floods. In W. Haeberli & C. Whiteman (Eds.), Snow and ice-related hazards, risks, and disasters (pp. 487–519). Amsterdam, The Netherlands: Elsevier.
- Clark, P. U., Marshall, S. J., Clarke, G. K. C., Hostetler, S. W., Licciardi, J. M., & Teller, J. T. (2001). Freshwater forcing of abrupt climate change during the last glaciation. Science, 293(5528), 283–287.
- Clarke, G. K. C., Leverington, D. W., Teller, J. T., & Dyke, A. S. (2004). Paleohydraulics of the last outburst flood from glacial Lake Agassiz and the 8200 BP cold event. Quaternary Science Reviews, 23(3–4), 389–407.
- Cossart, E., Braucher, R., Fort, M., Bourles, D. L., & Carcaillet, J. (2008). Slope instability in relation to glacial debuttressing in alpine areas (Upper Durance catchment, southeastern France): Evidence from field data and (10)Be cosmic ray exposure ages. Geomorphology, 95(1–2), 3–26.
- Costa, J. E. (1985). Floods from dam failures. Denver, CO: U.S. Geological Survey.
- Costa, J. E., & O’Connor, J. E. (1995). Geomorphically effective floods. In J. E. Costa et al. (Eds.), Natural and anthropogenic influences in fluvial geomorphology (pp. 45–56). Vancouver, WA: U.S. Geological Survey.
- Costa, J. E., & Schuster, R. L. (1988). The formation and failure of natural dams. Geological Society of America Bulletin, 100(7), 1054–1068.
- Crowley, T. J. (2000). Causes of climate change over the past 1000 years. Science, 289(5477), 270–277.
- Cutter, S. L., Barnes, L., Berry, M., Burton, C., Evans, E., Tate, E., & Webb, J. (2008). A place-based model for understanding community resilience to natural disasters. Global Environmental Change-Human and Policy Dimensions, 18(4), 598–606.
- Das, S., Kar, N. S., & Bandyopadhyay, S. (2015). Glacial lake outburst flood at Kedarnath, Indian Himalaya: A study using digital elevation models and satellite images. Natural Hazards, 77(2), 769–786.
- Davis, P. T., Menounos, B., & Osborn, G. (2009). Holocene and latest Pleistocene alpine glacier fluctuations: A global perspective. Quaternary Science Reviews, 28(21–22), 2021–2033.
- Desloges, J. R., & Church, M. (1992). Geomorphic implications of glacier outburst flooding—Noeick River Valley, British Columbia. Canadian Journal of Earth Sciences, 29(3), 551–564.
- Dietrich, A., & Krautblatter, M. (2016). Evidence for enhanced debris-flow activity in the Northern Calcareous Alps since the 1980s (Plansee, Austria). Geomorphology.
- Ding, Y., & Liu, J. (1992). Glacial lake outburst flood disasters in China. Annals of Glaciology, 16(1), 180–185.
- Dobhal, D. P., Gupta, A. K., Mehta, M., & Khandelwal, D. D. (2013). Kedarnath disaster: Facts and plausible causes. Current Science, 105(2), 171–174.
- Duissaillant, A., Benito, G., Buytaert, W., Carling, P., Meier, C., & Espinoza, F. (2010). Repeated glacial-lake outburst floods in Patagonia: An increasing hazard? Natural Hazards, 54(2), 469–481.
- Emmer, A., & Cochachin, A. (2013). Causes and mechanisms of moraine-dammed lake failures in Cordillera Blanca (Peru), North American Cordillera and Central Asia. AUC Geographica, 48, 5–15.
- Emmer, A., & Juřicová, A. (2017). Inventory and typology of landslide-dammed lakes of the Cordillera Blanca (Peru). WLF4—Landslides in Different Environments. Berlin: Springer.
- Emmer, A., Loarte, E., Klimeš, J., & Vilímek, V. (2015b). Recent evolution and degradation of bent Jatunraju glacier (Cordillera Blanca, Peru). Geomorphology, 228, 345–355.
- Emmer, A., Merkl, S., & Mergili, M. (2015a). Spatio-temporal patterns of high-mountain lakes and related hazards in western Austria. Geomorphology, 246, 602–616.
- Emmer, A., & Vilímek, V. (2013). Lake and breach hazard assessment for moraine-dammed lakes: An example from the Cordillera Blanca (Peru). Natural Hazards and Earth System Sciences, 13(6), 1551–1565.
- Emmer, A., & Vilímek, V. (2014). New method for assessing the susceptibility of glacial lakes to outburst floods in the Cordillera Blanca, Peru. Hydrology and Earth System Sciences, 18, 3461–3479.
- Emmer, A., Vilímek, V., Huggel, C., Klimeš, J., & Schaub, Y. (2016a). Limits and challenges to compiling and developing a database of glacial lake outburst floods. Landslides, 13(6), 1579–1584.
- Emmer, A., Vilímek, V., Klimeš, J., & Cochachin, A. (2014). Glacier retreat, lakes development and associated natural hazards in Cordillera Blanca, Peru. In W. Shanet al. (Eds.), Landslides in cold regions in the context of climate change, environmental science and engineering (pp. 231–252). Wallingford, U.K.: Springer.
- Emmer, A., Vilímek, V., & Zapata, M. L. (2016b). Hazard mitigation of glacial lake outburst floods in the Cordillera Blanca (Peru): The effectiveness of remedial works. Journal of Flood Risk Management.
- Evans, S. G., & Clague, J. J. (1994). Recent climatic change and catastrophic processes in mountain environments. Geomorphology, 10, 107–128.
- Frey, H., Haeberli, W., Linsbauer, A., Huggel, C., & Paul, F. (2010). A multi-level strategy for anticipating future glacier lake formation and associated hazard potentials. Natural Hazards and Earth System Sciences, 10(2), 339–352.
- Fuchs, S. (2008). Vulnerability to torrent processes. Transactions on Information and Communication Technologies, 39, 289–298.
- Gibbard, P. L., Head, M. J., Walkers, M. J. C., & Subcommission Quaternary Stratigra. (2010). Formal ratification of the Quaternary System/Period and the Pleistocene Series/Epoch with a base at 2.58 Ma. Journal of Quaternary Science, 25(2), 96–102.
- Grabs, W. E., & Hanisch, J. (1993). Objectives and prevention methods for glacier lake outburst floods (GLOFs). In G. J. Young (Ed.), Snow and glacier hydrology (proceedings of the Kathmandu Symposium, November 1992) (pp. 341–352). Great Yarmouth, U.K.: International Association of Hydrological Sciences (IAHS).
- Gruber, F. E., & Mergili, M. (2013). Regional-scale analysis of high-mountain multi-hazard and risk indicators in the Pamir (Tajikistan) with GRASS GIS. Natural Hazards and Earth System Sciences, 13(11), 2779–2796.
- Gudmundsson, M. T., Sigmundsson, F., & Bjornsson, H. (1997). Ice-volcano interaction of the 1996 Gjalp subglacial eruption, Vatnajokull, Iceland. Nature, 389(6654), 954–957.
- Haeberli, W. (1983). Frequency characteristics of glacier floods in the Swiss Alps. Annals of Glaciology, 4, 85–90.
- Haeberli, W. (2013). Mountain permafrost—Research frontiers and a special long-term challenge. Cold Regions Science and Technology, 96, 71–76.
- Haeberli, W., Buetler, M., Huggel, C., Lehmann Friedli, T., Schaub, Y., & Schleiss, A. J. (2016b). New lakes in deglaciating high-mountain regions—opportunities and risks. Climatic Change, 139, 201–214.
- Haeberli, W., Kääb, A., Mühll, D. V., & Teysseire, P. (2001). Prevention of outburst floods from periglacial lakes at Grubengletscher, Valais, Swiss Alps. Journal of Glaciology, 47(156), 111–122.
- Haeberli, W., Schaub, Y., & Huggel, C. (2016a). Increasing risks related to landslides from degrading permafrost into new lakes in de-glaciating mountain ranges. Geomorphology.
- Haeberli, W., & Whiteman, C. (2015). Snow and ice-related hazards, risks, and disasters. Amsterdam: Elsevier.
- Haemming, C., Huss, M., Keusen, H., Hess, J., Wegmuller, U., Ao, Z. G., & Kulubayi, W. (2014). Hazard assessment of glacial lake outburst floods from Kyagar glacier, Karakoram mountains, China. Annals of Glaciology, 55(66), 34–44.
- Hansen, J. E., Sato, M., Lacis, A., Ruedy, R., Tegen, I., & Matthews, E. (1998). Climate forcings in the industrial era. Proceedings of the National Academy of Sciences of the USA, 95(22), 12753–12758.
- Harrison, S., Glasser, N. F., Winchester, V., Haresign, E., Warren, C., & Jansson, K. (2006). A glacial lake outburst flood associated with recent mountain glacier retreat, Patagonian Andes. The Holocene, 16(4), 611–620.
- Harrison, W. D., Osipova, G. B., Nosenko, G. A., Espizua, L., Kääb, A., Fischer, L., . . . Lai, A. W. (2015). Glacier surges. In W. Haeberli & C. Whiteman (Eds.), Snow and Ice-related Hazards, Risks and Disasters (pp. 437–485). Amsterdam: Elsevier.
- Hauser, A. (1993). Remociones en masa en Chile. Servicio Nacional de Geologı ́a y Mineria de Chile Boletín, 45, 1–75.
- Heckmann, T., McColl, S., & Morche, D. (2016). Retreating ice: Research in pro-glacial areas matters. Earth Surface Processes and Landforms, 41(2), 271–276.
- Hegglin, E., & Huggel, C. (2008). An integrated assessment of vulnerability to glacial hazards: A case study in the Cordillera Blanca, Peru. Mountain Research and Development, 28(3–4), 299–309.
- Hemming, S. R. (2004). Heinrich events: Massive Late Pleistocene detritus layers of the North Atlantic and their global climate imprint. Reviews of Geophysics, 42(1), RG1005.
- Hewitt, G. (2000). The genetic legacy of the Quaternary ice ages. Nature, 405(6798), 907–913.
- Hewitt, K. (1982). Natural dams and outburst floods of the Karakoram Himalaya. In J. W. Glen (Ed.), Hydrological aspects of alpine and high mountain areas (pp. 259–269). International Association of Hydrological Sciences (IAHS).
- Hewitt, K. (2016). The human ecology of disaster risk in cold mountainous regions. In S. L. Cutter (Ed.), Oxford Research Encyclopedia—Natural Hazard Science. Oxford: Oxford University Press.
- Hubbard, B., Heald, A., Reynolds, J. M., Quincey, D., Richardson, S. D., Zapata, M. L., . . . Hambrey, M. J. (2005). Impact of a rock avalanche on a moraine-dammed proglacial lake: Laguna Safuna Alta, Cordillera Blanca, Peru. Earth Surface Processes and Landforms, 30, 1251–1264.
- Huggel, C., Clague, J. J., & Korup, O. (2012). Is climate change responsible for changing landslide activity in high mountains? Earth Surface Processes and Landforms, 37(1), 77–91.
- Huggel, C., Haeberli, W., Kääb, A., Bieri, D., & Richardson, S. (2004). An assessment procedure for glacial hazards in the Swiss Alps. Canadian Geotechnical Journal, 41(6), 1068–1083.
- Huggel, C., Kaab, A., Haeberli, W., Teysseire, P., and Paul, F. (2002). Remote sensing based assessment of hazards from glacier lake outbursts: a case study in the Swiss Alps. Canadian geotechnical journal, 39(2), 316–330.
- Hutchinson, E. G. (1957). Treatise on limnology. Volume I—Geography, physics and chemistry. New York: Wiley.
- Intergovernmental Panel on Climate Change (IPCC). (2013). Climate change 2013: The physical science basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). Cambridge, U.K.: Cambridge University Press.
- Ives, J. D. (1986). Glacial lake outburst floods and risk engineering in the Himalaya. Kathmandu, Nepal: International Centre for Integrated Mountain Development (ICIMOD).
- Ives, J. D., Shrestha, B. R., & Mool, P. K. (2010). Formation of glacial lakes in the Hindu Kush-Himalayas and GLOF risk assessment. Kathmandu, Nepal: International Centre for Integrated Mountain Development (ICIMOD).
- Kääb, A., Huggel, C., Fischer, L., Guex, S., Paul, F., Roer, I., . . . Weidmann, Y. (2005). Remote sensing of glacier- and permafrost-related hazards in high mountains: An overview. Natural Hazards and Earth System Sciences, 5(4), 527–554.
- Kalff, J. (2002). Limnology: Inland water ecosystems. Upper Saddle River, NJ: Prentice Hall.
- Kargel, J. S., Leonard, G. J., Shugar, D. H., Haritashya, U. K., Bevington, A., Fielding, E. J., … Young, N. (2016). Geomorphic and geologic controls of geohazards induced by Nepal’s 2015 Gorkha earthquake. Science, 351(6269), 140.
- Kattelmann, R. (2003). Glacial lake outburst floods in the Nepal Himalaya: A manageable hazard? Natural Hazards, 28, 145–154.
- Kershaw, J. A., Clague, J. J., & Evans, S. G. (2005). Geomorphic and sedimentological signature of a two-phase outburst flood from moraine-dammed Queen Bess Lake, British Columbia, Canada. Earth Surface Processes and Landforms, 30, 1–25.
- Klimeš, J., Novotný, J., Novotná, I., de Urries, B. J., Vilímek, V., Emmer, A., . . . Frey, H. (2016). Landslides in moraines as triggers of glacial lake outburst floods: Example from Palcacocha Lake (Cordillera Blanca, Peru). Landslides, 13(6), 1461–1477.
- Komori, J. (2008). Recent expansions of glacial lakes in the Bhutan Himalayas. Quaternery International, 184, 177–186.
- Korup, O. (2012). Earth’s portfolio of extreme sediment transport events. Earth-Science Reviews, 112(3–4), 115–125.
- Korup, O., & Tweed, F. (2007). Ice, moraine, and landslide dams in mountainous terrain. Quaternary Science Reviews, 26, 3406–3422.
- Krapesch, G., Hauer, C., & Habersack, H. (2011). Scale orientated analysis of river width changes due to extreme flood hazards. Natural Hazards and Earth System Sciences, 11(8), 2137–2147.
- Kropáček, J., Neckel, N., Tyrna, B., Holzer, N., Hovden, A., Gourmelen, N., . . . Hochschild, V. (2015). Repeated glacial lake outburst flood threatening the oldest Buddhist monastery in north-western Nepal. Natural Hazards and Earth System Sciences, 15(10), 2425–2437.
- Kruger, J., & Kjaer, K. H. (2000). De-icing progression of ice-cored moraines in a humid, subpolar climate, Kotlujokull, Iceland. Holocene, 10(6), 737–747.
- Lichtenhahn. C. (1971). Zwei Stollenbauten: Stollen im Eis zur Verhinderung von Ausbruchen eines Sees im Grubengletschergebiet (Wallis) und Stollen im Felsen zur unterirdischen Entwässerung des Rutschgebietes von Camp Vallemaggia (Tessin). Interprevent, 3, 465–475.
- Linsbauer, A., Frey, H., Haeberli, W., Machguth, H., Azam, M. F., & Allen, S. (2016). Modelling glacier-bed overdeepenings and possible future lakes for the glaciers in the Himalaya–Karakoram region. Annals of Glaciology, 57(71), 119–130.
- Lisiecki, L. E., & Raymo, M. E. (2005). A Pliocene-Pleistocene stack of 57 globally distributed benthic delta O-18 records. Paleoceanography, 20(1), PA1003.
- Lliboutry, L., Morales, B. A., Pautre, A., & Schneider, B. (1977). Glaciological problems set by the control of dangerous lakes in Cordillera Blanca, Peru. I. Historical failures of moranic dams, their causes and prevention. Journal of Glaciology, 18(79), 239–254.
- Mangerud, J., Jakobsson, M., Alexanderson, H., Astakhov, V., Clarke, G. C. K., Henriksen, M., … Svendsen, J. I. (2004). Ice-dammed lakes and rerouting of the drainage of northern Eurasia during the last glaciation. Quaternary Science Reviews, 23(11–13), 1313–1332.
- Mann, M. E., Zhang, Z. H., Rutherford, S., Bradley, R. S., Hughes, M. K., Shindell, D., . . . Ni, F. B. (2009). Global signatures and dynamical origins of the Little Ice Age and medieval climate anomaly. Science, 326(5957), 1256–1260.
- Maizels, J. (1997). Jokulhlaup deposits in proglacial areas. Quaternary Science Reviews, 16(7), 793–819.
- Margold, M., Jansson, K. N., Stroeven, A. P., & Jansen, J. D. (2011). Glacial Lake Vitim, a 3000-km3 outburst flood from Siberia to the Arctic Ocean. Quaternary Research, 76(3), 393–396.
- Mayewski, P. A., Rohling, E. E., Stager, J. C., Karlen, W., Maasch, K. A., Meeker, L. D., . . . Stieg, E. J. (2004). Holocene climate variability. Quaternary Research, 62(3), 243–255.
- McColl, S. (2012). Paraglacial rock-slope stability. Geomorphology, 153–154, 1–16.
- McKillop, R. J., & Clague, J. J. (2007a). Statistical, remote sensing-based approach for estimating the probability of catastrophic drainage from moraine-dammed lakes in Southwestern British Columbia. Global and Planetary Change, 56(1–2), 153–171.
- McKillop, R. J., & Clague, J. J. (2007b). A procedure for making objective preliminary assessments of outburst flood hazard from moraine-dammed lakes in southwestern British Columbia. Natural Hazards, 41(1), 131–157.
- Mergili, M. (2016). Observation and spatial modeling of snow- and ice-related mass movement hazards. In S. L. Cutter (Ed.), Oxford Research Encyclopedia—Natural Hazard Science. Oxford: Oxford University Press.
- Mergili, M., Emmer, A., Juřicová, A., Cochachin, A., Fischer, J.-T., Huggel, C., & Pudasaini, S. P. (forthcoming). Can we simulate complex hydro-geomorphic process chains? The 2012 multi-lake outburst flood in the Santa Cruz Valley (Cordillera Blanca, Perú). Earth Surface Processes and Landsforms.
- Mergili, M., & Schneider, F. (2011). Regional-scale analysis of lake outburst hazards in the southwestern Pamir, Tajikistan, based on remote sensing and GIS. Natural Hazards and Earth System Sciences, 11(5), 1447–1462.
- Morche, D., & Schmidt, K. H. (2012). Sediment transport in an alpine river before and after a dambreak flood event. Earth Surface Processes and Landforms, 37(3), 347–353.
- Morche, D., Schmidt, K. H., Heckmann, T., & Hass, F. (2007). Hydrology and geomorphic effects of a high-magnitude flood in an alpine river. Geografiska Annaler Series A-Physical Geography, 89A(1), 5–19.
- O’Connor, J. E., & Baker, V. R. (1992). Magnitude implications of peak discharges from glacial lake Missoula. Geological Society in America Bulletin, 104, 267–279.
- O’Connor, J. E., & Costa, J. E. (1993). Geologic and hydrologic hazards in glacierized basins in North America resulting from 19th and 20th century global warming. Natural Hazards, 8, 121–140.
- O’Connor, J. E., & Costa, J. E. (2004). The world’s largest floods, past and present: Their causes and magnitudes. Reston, VA: U.S. Geological Survey.
- O’Connor, J. E., Duda, J. J., & Grant, G. E. (2015). 1000 dams down and counting. Science, 348(6263), 496–497.
- O’Connor, J. E., Hardison, J. H., & Costa, J. E. (2001). Debris flows from failures of neoglacial-age moraine dams in the Three Sisters and Mount Jefferson Wilderness Areas, Oregon. Reston, VA: U.S. Geological Survey.
- Oppenheim, V. (1946). Sobre las Lagunas de Huaraz. Boletin de la Sociedad Geologica del Peru, 19, 68–80.
- Overpeck, J., Hughen, K., Hardy, D., Bradley, R., Case, R., Douglas, M., . . . Zielenski, G. (1997). Arctic environmental change of the last four centuries. Science, 278(5341), 1251–1256.
- Paul, F., Kääb, A., Maisch, M., Kellenberger, T., & Haeberli, W. (2004) Rapid disintegration of Alpine glaciers observed with satellite data. Geophysical Research Letters, 31(21), L21402.
- Pitman, E. B., Patra, A. K., Kumar, D., Nishimura, K., & Komori, J. (2013). Two phase simulations of glacier lake outburst flows. Journal of Computational Science, 4(1–2), 71–79.
- Portocarrero, C. A. (2014). Reducing the risk of dangerous lakes in the Peruvian Andes: A handbook for glacial lake management. Washington, DC: US Agency for International Development.
- Ray, P. K., Chattoraj, S. L., Bisht, M. P. S., Kannaujiya, S., Pandey, K., & Goswami, A. (2015). Kedarnath disaster 2013: Causes and consequences using remote sensing inputs. Natural Hazards, 81(1), 227–243.
- Reynolds, J. M. (2003). Development of glacial hazard and risk minimisation protocols in rural environments: Methods of glacial hazard assessment and management in the Cordillera Blanca, Peru. Flintshire, U.K.: Reynolds Geo-Sciences Ltd.
- Reynolds, J. M., Dolecki, A., & Portocarrero, C. (1998). Construction of a drainage tunnel as a part of glacial lake hazard mitigation at Hualcán, Cordillera Blanca, Peru. In J. G. Maund & M. Eddleston (Eds.), Geohazards in engineering geology (pp. 41–48). London: Geological Society.
- Richard, D., & Gay, M. (2004). GLACIORISK final report: Survey and prevention of extreme glaciological hazards in European mountainous regions. Brussels: European Commission.
- Richardson, S. D. (2010). Remote sensing approaches for early warning of GLOF hazard in the Hindu Kush—Himalayan region. Kathmandu, Nepal: United Nations International Strategy for Disaster Reduction (UN/ISDR).
- Richardson, S. D., & Reynolds, J. M. (2000a). An overview of glacial hazards in the Himalayas. Quaternary International, 65/66, 31–47.
- Richardson, S. D., & Reynolds, J. M. (2000b). Degradation of ice-cored moraine dams: Implications for hazard development. In M. Nakawo et al. (Eds.), Debris-covered glaciers (pp. 187–197). Proceedings of a workshop held in Seattle, Washington, USA, September 2000. Wallingford, U.K.: International Association of Hydrological Sciences (IAHS).
- Robitaille, A., & Dubois, J. M. M. (1995). Identification of characteristics features associated with glacial outburst. Geographie Physique et Quaternaire, 49(3), 435–457.
- Rounce, D. R., McKinney, D. C., Lala, J. M., Byers, A. C., & Watson, C. S. (2016). A new remote hazard and risk assessment framework for glacial lakes in the Nepal Himalaya. Hydrology and Earth System Sciences, 20(8), 3455–3475.
- Schomacker, A. (2008). What controls dead-ice melting under different climate conditions? A discussion. Earth-Science Reviews, 90(3–4), 103–113.
- Schwanghart, W., Worni, R., Huggel, C., Stoffel, M., & Korup, O. (2016). Uncertainty in the Himalayan energy–water nexus: Estimating regional exposure to glacial lake outburst floods. Environmental Research Letters, 11.
- Shrestha, A. B. (2010). Managing flash flood risk in Himalayas—Informational sheet #1/10. Kathmandu, Nepal: International Centre for Integrated Mountain Development (ICIMOD).
- Smith, D. G., & Fischer, T. G. (1993). Glacial Lake Agassiz—The Northwestern outlet and paleoflood. Geology, 21(1), 9–12.
- Smith, M. W., Carrivick, J. L., Hooke, J., & Kirkby, M. J. (2014). Reconstructing flash flood magnitudes using “structure-from-motion”: A rapid assessment tool. Journal of Hydrology, 519, 1914–1927.
- Somos-Valenzuela, M. A., Chisolm, R. E., Rivas, D. S., Portocarrero, C., & McKinney, D. C. (2016). Modeling glacial lake outburst flood process chain: The case of Lake Palcacocha and Huaraz, Peru. Hydrology and Earth System Sciences, 20(6), 2519–2543.
- Stefánsdottir, M. B., & Gíslason, S. R. (2005). The erosion and suspended matter/seawater interaction during and after the 1993 outburst flood from the Vatnajökull Glacier, Iceland. Earth and Planetary Science Letters, 237, 433–452.
- Stoffel, M., & Huggel, C. (2012). Effects of climate change on mass movements in mountain environments. Progress in Physical Geography, 36(3), 421–439.
- Stoffel, M., Khodri, M., Corona, C., Guillet, S., Poulain, V., Bekki, S., . . . Masson-Delmotte, V. (2015). Estimates of volcanic-induced cooling in the Northern Hemisphere over the past 1,500 years. Nature Geoscience, 8(10), 784–788.
- Strasser, M., Schindler, C., & Anselmetti, F. S. (2003). Late Pleistocene earthquake-triggered moraine dam failure and outburst of Lake Zurich, Switzerland. Journal of Geophysical Research-Earth Surface, 113(F2), F02003.
- Teller, J. T., Leverington, D. W., & Mann, J. D. (2002). Freshwater outbursts to the oceans from glacial lake Agassiz and their role in climate change during the last deglaciation. Quaternary Science Reviews, 21(8–9), 879–887.
- Thorndycraft, V. R., Cripps, J. E., & Eades, G. L. (2016). Digital landscapes of deglaciation: Identifying Late Quaternary glacial lake outburst floods using LiDAR. Earth Surface Processes and Landforms, 41(3), 291–307.
- Tomasson, H. (1996). The jokulhlaup from Katla in 1918. Annals of Glaciology, 22, 249–259.
- Tweed, F. S., & Russel, A. J. (1999). Controls on the formation and sudden drainage of glacier-impounded lakes: Implications for jokulhlaup characteristics. Progress in Physical Geography, 23(1), 79–110.
- Yamada, T. (1998). Glacier lake and its outburst flood in the Nepal Himalaya. Tokyo: Japanese Society of Snow and Ice.
- UGRH (2015). Consolidado de Actividades Realizadas en el Año 2015 Por la Unidad de Glaciología y Recursos Hídricos. Huaráz, Peru: Autoridad Nacional del Agua (ANA), Unidad de Glaciología y Recursos Hídricos (UGRH).
- Vilímek, V., Klimeš, J., Emmer, A., & Benešová, M. (2015). Geomorphologic impacts of the glacial lake outburst flood from lake no. 513 (Peru). Environmental Earth Sciences, 73(9), 5233–5244.
- Vilímek, V., Zapata, M. L., Klimeš, J., Patzelt, Z., & Santillán, N. (2005). Influence of glacial retreat on natural hazards of the Palcacocha Lake area, Peru. Landslides, 2, 107–115.
- Vuille, M., Francou, B., Wagnon, P., Juen, I., Kaser, G., Mark, B. G., & Bradley, R. S. (2008). Climate change and tropical Andean glaciers: Past, present and future. Earth-Science Reviews, 89(3–4), 79–96.
- Walder, J. S., & Costa, J. E. (1996). Outburst floods from glacier-dammed lakes: The effect of mode of lake drainage on flood magnitude. Earth Surface Processes and Landforms, 21(8), 701–723.
- Walder, J. S., & O’Connor, J. E. (1997). Methods for predicting peak discharge of floods caused by failure of natural and constructed earthen dams. Water Resources Research, 33(10), 2337–2348.
- Wang, S. J., & Jiao, S. T. (2015). Evolution and outburst risk analysis of moraine-dammed lakes in the central Chinese Himalaya. Journal of Earth System Science, 124(3), 567–576.
- Wang, W. C., Yao, T. D., Gao, Y., & Yang, X. X. (2011). A first-order method to identify potentially dangerous glacial lakes in a region of the southeastern Tibetan plateau. Mountain Research and Development, 31(2), 122–130.
- Watanabe, T., Kameyama, S., & Sato, T. (1995). Imja glacier dead-ice melt rates and changes in a supra-glacial lake, 1989–1994, Khumbu-Himal, Nepal—Danger of lake drainage. Mountain Research and Development, 15(4), 293–300.
- Watanabe, T., & Rothacher, D. (1996). The 1994 Lugge Tsho glacial lake outburst flood, Bhutan Himalaya. Mountain Research and Development, 16, 77–81.
- Westoby, M. J., Glasser, N. F., Brasington, J., Hambrey, M. J., Quincey, D. J., & Reynolds, J. M. (2014). Modelling outburst floods from moraine-dammed glacial lakes. Earth-Science Reviews, 134, 137–159.
- Westoby, M. J., Brasington, J., Glasser, N. F., Hambrey, M. J., Reynolds, J. M., Hassan, M.A.A.M., & Lowe, A. (2015). Numerical modelling of glacial lake outburst floods using physically based dam-breach models. Earth Surface Dynamics, 3(1), 171–199.
- Wirtz, A., Kron, W., Low, P., & Steuer, M. (2014). The need for data: Natural disasters and the challenges of database management. Natural Hazards, 70(1), 135–157.
- Worni, R., Huggel, C., Clague, J. J., Schaub, Y., & Stoffel, M. (2014). Coupling glacial lake impact, dam breach, and flood processes: A modeling perspective. Geomorphology, 224, 161–176.
- Xu, M. Z., Bogen, J., Wang, Z. Y., Bonsnes, T. E., & Gytri, S. (2015). Pro-glacial lake sedimentation from jokulhlaups (GLOF), Blamannsisen, northern Norway. Earth Surface Processes and Landforms, 40(5), 654–665.
- Zaginaev, V., Ballesteros-Canvas, J. A., Erokhin, S., Matov, E., Petrakov, D., & Stoffel, M. (2016). Reconstruction of glacial lake outburst floods in northern Tien Shan: Implications for hazard assessment. Geomorphology, 269, 75–84.
- Zapata, M. L. (2002). La dinamica glaciar en lagunas de la Cordillera Blanca. Acta Montana (ser. A Geodynamics), 19(123), 37–60.
- Zemp, M., Haeberli, W., Hoelzle, M., & Paul, F. (2006). Alpine glaciers to disappear within decades? Geophysical Research Letters, 33(13), L13504.
- Zemp, M., Frey, H., Gärtner-Roer, I., Nussbaumer, S. U., Hoelzle, M., Paul, F., Haeberli, W., . . . Vincent, C. (2015). Historically unprecedented global glacier decline in the early 21st century. Journal of Glaciology, 61(228), 745.
- Zhang, X. J., & Liu, S. Y., (2015). A framework of numerical simulation on moraine-dammed glacial lake outburst floods. Journal of Arid Land, 7(6), 728–740.