Glacial Lake Outburst

Definition

“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 hydrometeorological induced floods, with an exceptional erosion/transport potential; therefore, they can turn into flow-type movements, e.g. GLOF-induced debris flows (Emmer).

Facts and figures

A GLOF may have diverse causes and subsequent mechanisms, for example accordingly on 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 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 ; however, systematic investigation of the causes and mechanisms of GLOF, as well as database construction, are required in order to better understand the complex processes and, in turn, provide more effective hazard and risk management (Emmer).

 

The following direct causes of glacial lake outburst floods were documented:

  • Rapid slope movement into the lake
  • Heavy rainfall/snowmelt
  • Cascading processes (flood from a lake situated upstream)
  • Earthquake
  • Melting of ice incorporated in dam/forming the dam (including volcanic activity-triggered jökulhlaups)
  • Blocking of subsurface outflow tunnels (applies only to lakes without surface outflow or lakes with a combination of surface and subsurface outflow)
  • Long-term dam degradation (Emmer).

UN-SPIDER Regional Support Offices with hazard-specific expertise

Related content on the Knowledge Portal

  • The government-owned Landsat 7 was successfully launched on April 15, 1999, from the Western Test Range of Vandenberg Air Force Base, California, on a Delta-II expendable launch vehicle. The Earth observing instrument on Landsat 7, the Enhanced Thematic Mapper Plus (ETM+), replicates the capabilities of the highly successful Thematic Mapper instruments on Landsats 4 and 5.
    Landsat 7 is the most accurately calibrated Earth-observing satellite, i.e., its measurements are extremely accurate when compared to the same measurements made on the ground.  Landsat 7’s sensor has been called “the most stable, best characterized Earth observation instrument ever placed in orbit.”  Landsat 7’s rigorous calibration standards have made it the validation choice for many coarse-resolution sensors.
    Considered a calibration-triumph, the Landsat 7 mission went flawlessly until May 2003 when a hardware component failure left wedge-shaped spaces of missing data on either side of…

    read more
    15/04/1999
  • The satellites SPOT 4 (Satellite Probatoire de l'Observation de la Terre) was a second generation of SPOT earth observation satellite operated by Spot Image.

    SPOT 4 used the improved bus design, which differed from the earlier SPOT series by having an increased lifetime of five years instead of three, a new extended platform design and service module, which can accommodate twice the payload. The propulsion module consists of a frame made of aluminum bars and two capillary tanks holding 158 kg of hydrazine.

    The prime imaging instrument was HRVIR (High-Resolution Visible and Infrared sensor), which consisted of two pushbroom imaging units, an improved version of HRV. The two spectral modes are panchromatic and multispectral. The panchromatic band had a resolution of 10 meters, and the three multispectral bands (G,R,NIR) have resolutions of 20 meters.

    An additional sensor for SPOT-4, called Vegetation or VMI (Vegetation Monitoring Instrument), with a ground…

    read more
    24/03/1998
  • The satellites SPOT 1, 2 and 3 (Satellite Probatoire de l'Observation de la Terre) were the first generation of SPOT earth observation satellites operated by Spot Image.

    The first generation SPOT satellites were built on the SPOT Mk.1 bus with a lifetime of three years.

    The SPOT satellites were identical, with each carrying two identical HRV (High Resolution Visible) imaging instruments that were able to operate in two modes, either simultaneously or individually. The two spectral modes are panchromatic and multispectral. The panchromatic band had a resolution of 10 meters, and the three multispectral bands (G,R,NIR) have resolutions of 20 meters.

    SPOT 3 was orbited on 26 September 1993 on an Ariane-40 H10 rocket. It ended operations in November 1996 due to problems with its stabilization system.

    Instruments: 2 HRVs
    - 4 spectral bands (1 panchromatic, 3 multispectral)
    - imaging swath: 60km x 60km to 80km

    26/09/1993
  • The satellites SPOT 1, 2 and 3 (Satellite Probatoire de l'Observation de la Terre) were the first generation of SPOT earth observation satellites operated by Spot Image.

    The first generation SPOT satellites were built on the SPOT Mk.1 bus with a lifetime of three years.

    The SPOT satellites were identical, with each carrying two identical HRV (High Resolution Visible) imaging instruments that were able to operate in two modes, either simultaneously or individually. The two spectral modes are panchromatic and multispectral. The panchromatic band had a resolution of 10 meters, and the three multispectral bands (G,R,NIR) have resolutions of 20 meters.

    SPOT-2 was launched on 22 January 1990, on an Ariane-40 H10 rocket. It operated until July 2009. Its orbit was lowered to ensure reentry within 25 years.

    Instruments: 2 HRVs
    - 4 spectral bands (1 panchromatic, 3 multispectral)
    - imaging swath: 60km x 60km to 80km

    22/01/1990
  • The satellites SPOT 1, 2 and 3 (Satellite Probatoire de l'Observation de la Terre) were the first generation of SPOT earth observation satellites operated by Spot Image.

    The first generation SPOT satellites were built on the SPOT Mk.1 bus with a lifetime of three years.

    The SPOT satellites were identical, with each carrying two identical HRV (High Resolution Visible) imaging instruments that were able to operate in two modes, either simultaneously or individually. The two spectral modes are panchromatic and multispectral. The panchromatic band had a resolution of 10 meters, and the three multispectral bands (G,R,NIR) have resolutions of 20 meters.

    SPOT 1 was launched with the last Ariane-1 rocket on 22 February 1986. At the end of operations in 2003, the orbit was lowered to gradually lose altitude until reentry.

    Instruments: 2 HRVs
    - 4 spectral bands (1 panchromatic, 3 multispectral)
    - imaging swath: 60km x 60km to 80km…

    22/02/1986
  • Landsat 5 was launched from Vandenberg Air Force Base in California on March 1, 1984, and like Landsat 4, carried the Multispectral Scanner (MSS) and the Thematic Mapper (TM) instruments. Landsat 5 delivered Earth imaging data nearly 29 years - and set a Guinness World Record For 'Longest Operating Earth Observation Satellite', before being decommissioned on June 5, 2013.
    The Landsat 5 satellite orbited the the Earth in a sun-synchronous, near-polar orbit, at an altitude of 705 km (438 mi), inclined at 98.2 degrees, and circled the Earth every 99 minutes.  The satellite had a 16-day repeat cycle with an equatorial crossing time: 9:45 a.m. +/- 15 minutes.  Landsat 5 data were acquired on the Worldwide Reference System-2 (WRS-2) path/row system, with swath overlap (or sidelap) varying from 7 percent at the Equator to a maximum of approximately 85 percent at extreme latitudes. 
    Landsat 5 long outlived its original three-year design life. Developed by NASA and launched in…

    read more
    01/03/1984
  • The Copernicus DEM is a Digital Surface Model (DSM) which represents the surface of the Earth including buildings, infrastructure, and vegetation. The Copernicus DEM is provided in 3 different instances. Two worldwide coverages at 90m (GLO-90) and 30m (GLO-30) resolution are openly available to the public for download via the PANDA Catalogue and FTP. A further European coverage (EEA-10) is provided at 10m resolution, but data is restricted to eligible users who meet required access rights.
  • The Copernicus DEM is a Digital Surface Model (DSM) which represents the surface of the Earth including buildings, infrastructure, and vegetation. The Copernicus DEM is provided in 3 different instances. Two worldwide coverages at 90m (GLO-90) and 30m (GLO-30) resolution are openly available to the public for download via the PANDA Catalogue and FTP. A further European coverage (EEA-10) is provided at 10m resolution, but data is restricted to eligible users who meet required access rights.
  • Facebook Connectivity Lab in collaboration with the Center for International Earth Science Information Network (CIESIN) at Colombia University combines machine vision AI with satellite imagery and census information to create population density maps. With the integration of demographic information, specifically related to age and gender, these maps collectively provide information on both the location and the demographic of a population in a certain country. The population density maps cover the majority of countries around the world.
  • Facebook Connectivity Lab in collaboration with the Center for International Earth Science Information Network (CIESIN) at Colombia University combines machine vision AI with satellite imagery and census information to create population density maps. With the integration of demographic information, specifically related to age and gender, these maps collectively provide information on both the location and the demographic of a population in a certain country. The population density maps cover the majority of countries around the world.

Term Parents

UN-SPIDER Regional Support Offices with hazard-specific expertise