visualizing Nepal’s earthquake disaster: reblogs & links

Nepal earthquake on the radar

On 25 April, a 7.8-magnitude earthquake struck Nepal, claiming over 5000 lives and affecting millions of people. Satellite images are being used to support emergency aid organisations, while geo-scientists are using satellite measurements to analyse the effects of the earthquake on the land.

Radar imagery from the Sentinel-1A satellite shows that the maximum land deformation is only 17 km from Nepal’s capital, Kathmandu, which explains the extremely high damage experienced in this area.

By combining Sentinel-1A imagery acquired before and after the quake, changes on the ground that occurred between the two acquisition dates lead to rainbow-coloured interference patterns in the combined image, known as an ‘interferogram’, enabling scientists to quantify the ground movement.

Nepal_earthquake

Nepal_earthquake_deformation

Scientists are measuring the Nepal earthquake by bouncing radar beams off Kathmandu from space

The ground has shifted beneath Nepal’s feet, and space agencies around the globe are rushing to measure it…Using satellites that bounce radar waves off the earth and listen to the echo, scientists are able to calculate the distance between those satellites and the earth. Comparing the measured distances before and after the earthquake shows how much the earth has changed shape.

nepal_displacement_germans_004

Data collected by the European Space Agency’s Sentinel-1A satellite and analyzed by Deutsches Zentrum für Luft-und Raumfahrt, a research center of the German government, show that areas near Kathmandu were a meter closer to the satellite on April 29 than on April 17. Areas north of the city were found to be nearly a meter farther away.

This type of measurement isn’t perfect. Radar can be scattered by snow and heavy vegetation, according to NASA, making areas covered with those features hard to compare. Satellites also don’t look straight down on all areas of the earth, but at an angle while they orbit from pole to pole.

nepal_displacement_jpl_004This website of UN OCHA is a good portal for ongoing status updates, assessments and other tech info about the situation in affected areas.

World Food Program which coordinates the distribution of food and other relief goods regularly publishes a report compiled by its Nepal Food Security Monitoring System (NeKSAP) field teams added with other relevant info. Click on the image below for access to the currently latest update:

WFP_3rd report

Another very useful resource for those in the field is HDX, a collaboration between UN OCHA and a design firm to create a user friendly data sharing platform, described in this article on Fastcompany.

About roger henke

Still figuring out the story line that would satisfy myself here. Listening to what my family and friends evoke, what the words I absorb, the images that move me, the movements that still me, point to.
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One Response to visualizing Nepal’s earthquake disaster: reblogs & links

  1. Paul says:

    Quite extraordinary the power, majesty and beauty of earth….and humans are so inconsequential. I wonder how rainfall run off and river flow has been affected.

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