Photonics for Nepal earthquake response: seven ways and counting

Photonics technologies are helping Nepal cope with recent devastating earthquakes.
(Image: GlobalMedic)

When massive, lethal earthquakes hit Nepal earlier this spring, photonics technologies from satellites to smartphones were employed to aid first responders and follow-on relief efforts. Photonics is also helping to predict future earthquake locations and possibly mitigate the potential for destruction, reported Rebecca Pool in the SPIE Newsroom. Some highlights from the article:

1. High-resolution satellite imagery: Immediately after the first earthquake, the Global Disaster Alert and Coordination System, a joint United Nations and European Commission initiative, instructed the UN’s high-resolution satellite imagery program, UNOSAT, and partners to start mapping the region. Images of priority regions were swiftly integrated into a web map.

2. Interferograms: To pinpoint areas at greatest risk from future earthquakes, the European Space Agency has produced interferograms from data captured by its radar satellite Sentinel-1A. Imagery acquired before and after the earthquake has been combined to produce interference patterns that researchers use to quantify ground movement.

Interferogram over Kathmandu, Nepal,
generated from two Sentinel-1A
scans on 17 and 29 April 2015, before
and after the 25 April earthquake.
(Copyright Contains Copernicus data
(2015)/ESA/DLR Microwaves and
Radar Institute/GFZ/e-GEOS/INGV-ESA
SEOM INSARAP study)

3. Radar satellite measurements plus GPS: ESA has been working with Cambridge Earth Systems Sciences to combine radar satellite measurements with GPS data and general seismic observations. Researchers can thereby better understand the physics of Nepal's earthquakes and model what's happened below the earth's surface to assess future potential earthquakes.

... plus seismic observations: Researchers from Caltech and the NASA Jet Propulsion Lab (JPL) have combined satellite radar-imaging data with GPS data and worldwide seismic observations to estimate the slippage of the fault beneath Nepal. The research forms part of the Advanced Rapid Imaging and Analysis project, providing tools and data for relief groups.

4. UAV-captured photo and video: Images from drones -- unmanned aerial vehicles (UAVs) -- were among the first to reveal post-earthquake devastation and have helped responders pinpoint where aid is needed. Aeryon Labs has supported GlobalMedic by supplying three small unmanned aerial systems (sUASs) and a flight engineer to capture aerial photography and live videography for detailed mapping of disaster zones. Infrared cameras can capture images closer to the ground than satellites or manned aircraft, with operators able to locate a human face some 300m away.

UNOSAT's live web maps combine
layers of data to, for example,
illustrate the relationship between
building damange assessments
and ground displacement. The
circles illustrate the distance from
the epicenter of the first Nepal
earthquake. (Image: UNOSAT)

5. Low-power microwave radar: A novel search-and-rescue technology dubbed FINDER -- Finding Individuals for Disaster and Emergency Response -- located four men trapped under some ten feet of rubble. Under development by the U.S. Department of Homeland Security Science and Technology Directorate and NASA JPL, FINDER uses low-power microwave radar to detect small movements from breathing and heartbeats of buried victims.

6. Crowdsourced image data: Crowdsourcing has played a massive part in recovery and rescue missions as well. As part of its relief efforts, commercial satellite operator DigitalGlobe activated Tomnod, a crowdsourcing platform that has allowed online volunteers to pore over satellite images, comparing new images with old, and to tag damaged infrastructure.

More than 30,000 volunteers have used the platform since the first Nepal earthquake, said DigitalGlobe's Georgios Ouzounis. Thousands of damaged roads, buildings and areas of major destruction have been catalogued. Relief groups have been able to target areas with the largest number of survivors in need of food, water, tents and medical supplies.

7. Smartphone app: UNOSAT has developed a free smartphone app called UN-ASIGN that automatically uploads photos taken by volunteers to the organisation's web-maps. In Nepal, volunteer images have validated satellite imagery and provided accurate details on damage in specific locations.

Read more about photonics technology being used by responders and aid teams in Nepal and see more images, on the SPIE Newsroom.