15 Feb 2023
Images and processed data of affected regions provided to authorities to support recovery and support procedures.
NASA Administrator Bill Nelson commented, “NASA is our eyes in the sky, and our teams of experts are working hard to provide valuable information from our Earth-observing fleet to first responders on the ground.”
One of NASA’s key capabilities is an expertise with synthetic aperture radar, or SAR. Viewing Earth in all weather conditions, day or night, SAR is used to measure how the ground moves and built landscape changes after this type of event.
Scenes collected before and after the earthquake were used by a team of scientists from the Earth Observatory of Singapore and NASA’s Jet Propulsion Laboratory in Southern California to create a damage proxy map for Turkey. These maps compare before and after radar images of a given event to see how the landscape has changed.
Such maps are made available to organizations such as the U.S. State Department, the California Seismic Safety Commission, Miyamoto Global Disaster Relief, and the World Bank.
“NASA takes seriously its obligation to support open science, and make information widely accessible,” said Lori Schultz, NASA’s disaster coordinator for this earthquake. “We don’t know everyone who is using this information or how, but we are fortunate to have heard back from a few groups. For instance, the World Central Kitchen – which is providing food to those who’ve been displaced – have let us know they make use of it.”
By making use of data from the Commercial SmallSat Data Acquisition program, which acquires observations from commercial satellites to help with NASA’s research goals, as well as from NOAA and international space agencies in Europe and Japan, scientists can spot areas that might be prone to increased landslide risks.
While not in use yet, NASA scientists are hoping to add a new tool to assess the aftermath of the quake. The Earth Surface Mineral Dust Source Investigation, or EMIT, instrument was launched to the International Space Station in July 2022. As part of its observations of the composition of material in Earth’s atmosphere, it can assess methane emissions.
“Relief efforts include tracking cascading disasters, such as natural hazard-triggered technological disasters,” said Shanna McClain, manager of NASA’s Disaster Program. “Damaged infrastructure and pipeline bursts are something we want to identify quickly to protect the health of people nearby.”
ESA presents its earthquake insights
At the same time as NASA announced the availability of its images and data pertaining to the earthquake, the European Space Agency also made available its relevant observations.
The ESA stated on February 13th: “Satellite data are being used to help emergency aid organisations, while scientists have begun to analyse ground movement – aiding risk assessments that authorities will use as they plan recovery and reconstruction, as well as long-term research to better model such events.”
Following the earthquakes, Turkish authorities, along with the United Nations and the International Federation Red Cross & Red Crescent Societies, activated the International Charter ‘Space and Major Disasters.
By combining Earth observation assets from different space agencies, the Charter provides satellite images of the affected areas to define the extent of the disaster and support local teams with their rescue efforts.
Following the activation, more than 350 crisis images from 17 space agencies across the world were delivered. These can be used to generate damage and situation maps to help estimate the hazard impact and manage relief actions in the affected areas. The maps can be used by rescuers to orient themselves amongst the rubble, identify which roads to take, which bridges to avoid in case of collapse. The data will help guide them to destroyed buildings in remote areas, where help is hard to get.
Along with the Charter, the Copernicus Emergency Mapping Service has also been activated. The service, which has a cooperation agreement for sharing data and collaborating with the Charter, also uses observations from multiple satellites to provide on-demand mapping.
Damage grading maps from the service show the geographic extent of damaged areas. The service used high-resolution optical images, including those from Pleiades over 20 areas of interest covering an area of 664 sq km.
Philippe Bally, ESA representative of the International Charter, commented, “In order to support the assessment of the impact of the earthquakes that hit Türkiye and Syria, we require imagery with the highest possible spatial resolution over many areas of interest. Tasking Earth observation missions was challenging because of the cloud coverage over the region on the hours and days following the activation.”
Simonetta Cheli, Director of Earth Observation Programmes at ESA, commented, “Space is very relevant in cases of natural disasters such as the Türkiye–Syria earthquakes. It is our job when a natural disaster or a humanitarian crisis occurs to coordinate via the International Charter with partner agencies and with the Copernicus Emergency Mapping Services. We are closely following efforts to provide timely Earth observation data to disaster relief teams on the ground.”
There are other wider geological implications to the quake that may have consequences in the longer term that are slowly coming into focus. In the coastal city of İskenderun, there appears to have been significant subsidence, which has resulted in flooding, while the quake has left many hillsides around the country at a serious risk of landslide.
Radar imagery from satellites allows scientists to observe and analyse the effects that earthquakes have on the land. The Copernicus Sentinel-1 mission carries a radar instrument that can sense the ground and can ‘see’ through clouds, whether day or night. With its 250 km-wide swath over land surfaces, Sentinel-1 gives scientists a broad view of the displacement, allowing them to examine the ground displacement caused by this earthquake and develop the scientific knowledge of quakes.
Researchers use interferometry to compare before-and-after views after an earthquake has hit. In this case, data from Sentinel-1 have been combined to measure the coseismic surface displacement, or changes on the ground, that occurred between the two acquisitions. This leads to an interferogram that shows a colourful interference pattern and allows scientists to quantify surface displacement.
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