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Events

Dec 2015 - Jan 2016 US Midwest Floods

 

Download flood extent maps at http://aria-share.jpl.nasa.gov/events/20160111-US_Midwest_Floods/

In response to the December 2015 - January 2016 US Midwest Floods along the Mississippi River, the ARIA project produced flood extent maps derived from Synthetic Aperture Radar data of ALOS-2 satellite operated by Japanese Aerospace Exploration Agency's (JAXA). The maps are available in four different data types - KMZ files with PNG images, KMZ files with polygons, GeoTiff files, and Shapefiles. The KMZ files have three different layers - blue, red, and transparent. The blue and red colors represent areas of potential floods, and blue is likely due to rough surface replaced with smooth water (or open water), whereas the red likely due to floods in the areas with tall vegetation that enhanced the double bouce of radar signal. The GeoTiff and Shapefile are composed of two files for each frame that represent open water (*open.tif/shp) and vegetated water (*veg.tif/shp). These maps were not validated with independent observations such as optical imagery or ground observations. The figure below shows an area including the City of Memphis. The map was created by comparing a pre-flood (2015-09-30) and during-the-flood (2016-01-06) SAR scenes. Depending on the irrigation condition of the agricultural lands on those dates, there may be false positives. 
 
This flood extent maps should be used as guidance to identify flooded areas, and may be less reliable over urban areas. Original data ALOS-2 PALSAR-2 Product - ©JAXA (2016). All Rights Reserved.
 
 
 
 
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M7.8 Gorkha, Nepal Earthquake, April 25, 2015

 

In response to the April 25, 2015 M7.8 Gorkha, Nepal Earthquake, the ARIA project is providing valuable information for the ongoing response to the April 25, 2015 M7.8 Gorkha earthquake in Nepal. The quake has caused significant regional damage and a humanitarian crisis. 

Damage Proxy Map

The data products include a Damage Proxy Map, which covers the region around Kathmandu, was processed by the Advanced Rapid Imaging and Analysis (ARIA) team at JPL and Caltech using X-band interferometric synthetic aperture radar data from ASI's COSMO-SkyMed satellite constellation. The technique uses a prototype algorithm to rapidly detect surface changes caused by natural or human-produced damage. The assessment technique is most sensitive to destruction of the built environment. When the radar images areas with little to no destruction, its image pixels are transparent. Increased opacity of the radar image pixels reflects damage, with areas in red reflecting the heaviest damage to cities and towns. The color variations from yellow to red indicate increasingly more significant ground surface change. The time span of the data for the change is Nov. 24, 2014 to April 29, 2015. Each pixel in the damage proxy map is about 100 feet (30 meters) across.

The perspective image (above)  shows the DPM overlaid on the terrain with the locations of damaged buildings identified by the National Geospatial-Intelligence Agency (NGA) preliminary damage assessment, indicated by the red and purple dots. As an example, the images on the side show how red regions in the DPM correlate with damaged buildings, as shown by the collapsed structures in the "after" image. The base map images were provided by Google. Before and after images were provided by DigitalGlobe.

 

Surface Deformation and Fault Slip Model

The ARIA team analyzed interferometric synthetic aperture radar images from the European Union’s Copernicus Sentinel-1A satellite, operated by the European Space Agency and also available from the Alaska Satellite Facility (https://www.asf.alaska.edu), to calculate a map of the deformation of Earth’s surface caused by the quake. This false-color map shows the amount of permanent surface movement caused almost entirely by the earthquake, as viewed by the satellite, during a 12-day interval between two Sentinel-1 images acquired on April 17 and April 29, 2015. 

In the map, surface displacements are seen as color contours (or "fringes"), where each color cycle represents 8 inches (20 centimeters) of surface motion. The contours show the land around Kathmandu has moved upward by more than 40 inches (1 meter). Areas without the color contours have snow or heavy vegetation that affects the radar measurements. Scientists use these maps to build detailed models of the fault and associated land movements to better understand the impact on future earthquake activity. The background image is from Google Earth. The map contains Copernicus data (2015). 
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Using a combination of space geodetic observations (GPS data measured in and near the April 25, 2015, Gorkha earthquake in Nepal and satellite radar imaging data) and seismic observations from instruments distributed around the world, the ARIA team have constructed preliminary estimates of how much the fault responsible for the earthquake moved below Earth's surface (as viewed from above and indicated by the colors and contours within the rectangle). The peak fault slip exceeds 19.7 feet (6 meters). GPS observations and data predictions (indistinguishable) are indicated by the arrows. Aftershocks are indicated by the red dots. Background color and shaded relief indicate regional variations in topography. Barbed lines indicate the surface expression of the primary regional fault structures (barbed lines), where the faults dive northwards into the Earth below the Himalaya. All original GPS data are from a network originally installed by Caltech under support of the Gordon and Betty Moore Foundation. 
Using the above model, we can predict a spatially continuous map of the surface movement caused by the earthquake. In the above figure, color represents vertical movement and the scaled arrows indicate direction and magnitude of horizontal movement. Aftershocks are indicated by the red dots. Background color and shaded relief indicate regional variations in topography. Barbed lines indicate the surface expression of the primary regional fault structures (barbed lines), where the faults dive northwards into the Earth below the Himalaya.
 

Links to ARIA Data Products and Images:

Damage Proxy Map (kmz): http://aria-share.jpl.nasa.gov/events/20150425-Nepal_EQ/DPM/ARIA_DPM_v0.5u_CSKd_20150430.kmz

Sentinel 1a Interferogram (kmz): http://aria-share.jpl.nasa.gov/events/20150425-Nepal_EQ/interferogram/ARIA_Coseismic_Sentinel1A_interferogram-trackA158-20150402-0426.kmz

Sentinel 1a Interferogram (jpg): http://aria-share.jpl.nasa.gov/events/20150425-Nepal_EQ/interferogram/ARIA_Coseismic_Sentinel1A_interferogram-trackA158-20150402-0426a.jpg.

GPS Coseismic Offsets (ascii file):  http://aria-share.jpl.nasa.gov/events/20150425-Nepal_EQ/GPS/20150425Nepal_ARIA_Rapid_Offsets_v1.txt

GPS Coseismic Offsets (pdf): http://aria-share.jpl.nasa.gov/events/20150425-Nepal_EQ/GPS/20150425Nepal_ARIA_Rapid_Offsets_v1.pdf

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M6.0 South Napa Earthquake, August 24, 2014

In response to the August 24, 2014 M6.0 South Napa Earthquake, the ARIA team has generated coseismic GPS displacements, coseismic InSAR displacements, and a Damage Proxy Map. The above image is an Interferometric Synthetic Aperture Radar (InSAR) map of coseismic displacement (unwrapped interferogram) in the radar line-of-sight (LOS, 29 degrees from vertical and roughly west) caused by the 2014/08/24 M6.0 South Napa Earthquake, California. Derived from COSMO-SkyMed data acquired on 2014/07/26 and 2014/08/27. Processed by ARIA team at JPL-Caltech in collaboration with the Italian Space Agency (ASI) and University of Basilicata. The epicenter indicated with the red star is from USGS NEIC. The blue line indicates the North Bay Aqueduct. COSMO-SkyMed data (c) ASI 2014.
 
These results have been posted to the California Earthquake Clearinghouse and Southern California Earthquake Center Response Forum.  The InSAR displacement maps are being used by field geologist to identify additional surface fault ruptures. 
 
Image files with interferograms can be downloaded from the following links: 

An Image file with Damage Proxy Map can be downloaded from:

Files with GPS results can be downloaded here:

 
 

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Damage detection in New York City hit by Hurricane Sandy

ARIA team responded to Hurricane Sandy and manually produced a damage proxy map (DPM) of New York City using X-band radar data from COSMO-SkyMed satellites. The team coordinated a group of GIS experts to validate each pixel of the DPM to remove false positives, comparing with pre-event Google Earth image and post-event NOAA's aerial photographs. The data was acquired on Day 5, the DPM was created on Day 11, and the validated product on Day 15. The product was delivered to the International Charter, and the response report is available online at http://www.giscorps.org/index.php?option=com_content&task=view&id=129&It.... The results demonstrate great potential of InSAR data and future automated system ARIA team is building.   
 

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2011 M7.2 Earthquake in Van, Turkey

COSMO-SkyMed interferogram of 2011 Van Earthquake

We have done analysis of InSAR, GPS and seismic data for the 2011/10/23 Mw 7.2 earthquake near Van, Turkey to develop models for the fault slip. Publication has recently been accepted for Seismological Research Letters.

2010 M7.0 Earthquake in Haiti

Satellite radar derived color contour maps of ground movement due to the January 12, 2010 M7 earthquake in Haiti.  Each color cycle corresponds to 11.8 cm of motion.  The white star denotes the epicenter location.  The red rectangle is the inferred north-dipping fault model at depth, with the solid line being the surface projection of the model.

 
Satellite radar derived color contour maps of ground movement due to the January 12, 2010 M7 earthquake in Haiti.  Each color cycle corresponds to 11.8 cm of motion.  The white star denotes the epicenter location.  The red rectangle is the inferred north-dipping fault model at depth, with the solid line being the surface projection of the model. 

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