11-Feb-2023: Glacial Lake Outburst Flood (GLOF) threatens the future of millions of people worldwide
Key highlights and facts from a recent study on Glacial Lake Outburst Floods (GLOFs):
Global Risk of GLOF
- Up to 15 million people are at risk.
- Greatest threat is estimated in mountainous regions of Asia and South America.
- 9.3 million (62%) people are exposed in High Mountain Asia (HMA).
- 1 million people live within the 10 kms of a glacial lake in Asia.
- India, Pakistan, Peru, and China account for over half of those at risk globally.
Most Dangerous Basins
- Pakistan (Khyber Pakhtunkhwa basin), Peru (Santa basin), and Bolivia (Beni basin). 1.2 million, 0.9 million, and 0.1 million people are respectively at risk.
Rapid Glacial Melt
- Glaciers across the Andes have undergone rapid deglaciation in the last 20 years.
- 25 glacial lakes in the Himalayas have seen an increase in water spread area since 2009.
- 40% increase in water spread in India, China, and Nepal.
Impact and Threat
- GLOFs can catastrophically threaten lives, livelihoods, and infrastructure.
- Floods can destroy vital infrastructure.
- Populations within 10-15 km of the source lake may not have sufficient time to evacuate.
Suggestions for Action
- Urgent need for improved Early Warning Systems.
- Evacuation drills and community outreach needed for rapid warnings and emergency action in highly exposed areas.
The Moment Magnitude Scale (MMS) is a logarithmic scale used to measure the magnitude of earthquakes. It was developed in the 1970s by seismologists Thomas Hanks and Hiroo Kanamori as a replacement for the Richter magnitude scale, which was found to be inadequate for measuring larger earthquakes.
The MMS is based on the seismic moment of an earthquake, which is a measure of the total energy released during an earthquake. It takes into account the size of the fault that ruptured, the amount of slip on the fault, and the rigidity of the rock in the fault zone. The seismic moment is calculated using seismograms recorded at seismic stations, and the resulting value is used to determine the earthquake's magnitude.
The MMS is expressed in whole numbers and decimal fractions, with each whole number representing a tenfold increase in the amplitude of ground motion and a 32-fold increase in energy release. For example, an earthquake with a magnitude of 7.0 releases 32 times more energy than an earthquake with a magnitude of 6.0.
The MMS has become the standard measure of earthquake magnitude and is used by seismologists worldwide. It provides a more accurate and consistent measure of earthquake size, particularly for larger earthquakes, and is also more suitable for use in earthquake hazard assessment and engineering design.
30-Jan-2023: Extremely cold weather in Asia is linked to Polar Vortex
Polar Vortex
- Refers to an expanse of cold air that circles the Arctic
- Occasionally shifts south from the North Pole, causing extremely cold weather
- Vortex: counterclockwise flow of air that keeps colder air near the Poles
- Exists near poles, weakens in summer, strengthens in winter
- Lack of consensus, but believed to become more frequent and pronounced with a warming planet