Last Updated : October 6, 2015

The 2015 Chile Earthquake: Crustal deformation detected by ALOS-2 data

Crustal Deformation Observed by Synthetic Aperture Radar (SAR)

Released: Oct. 6, 2015 Japanese version of this page

Crustal Deformation revealed by InSAR

A huge earthquake (Mw8.3, USGS) occurred in Chile on September 16, 2015. We applied interferometric analysis using ALOS-2/PALSAR-2 data to measure the crustal deformation caused by the earthquake.

Displacement with over 1 m centered around 50 - 70 km north from the epicenter at the coast area has been revealed by the InSAR results. While the descending interferogram (observed from east) shows the displacement away from the satellite, the ascending interferogram (observed from west) shows the displacement toward the satellite, meaning that the great westward movement occurred. The observed deformation patterns also imply that the largest slip area is located in north of the hypocenter.

Note that these InSAR results would be affected by noises due to ionospheric and tropospheric delay.

The result is possibly updated with further elaborated analyses.

Interferograms

Click the images below to enlarge.
 

Image: Fig. 1

Fig. 1 [PNG: 1.96MB]

Image: Fig. 2

Fig. 2 [PNG: 585KB]

Image: Location map

Location map

 

Fig.
#
Date Time
(UTC)
Flight
Dir.
Beam
Dir.
Obs.
Mode
*1
Incidence
Angle
Bperp KMZ
1 2015/07/30
2015/09/24
15:59 Des. Right W-W 25°-45° -214m 4.6MB
2 2015/02/22
2015/09/20
05:23 Asc. Right F-F 34°-39° +163m 2.7MB

*1 W: ScanSAR(Normal), F: Stripmap(Fine[10m])
(cf. ALOS-2 Project / PALSAR-2 (JAXA))

Analized by GSI from ALOS-2 raw data of JAXA.
These results were obtained through the activity of the SAR analysis working group of the Coordinating Committee for Earthquake Prediction.


The 2015 Chile Earthquake

Date-Time September 16, 2015 19:54 (Local Time) 22:54 (UTC)
Hypocenter Location 31.570°S, 71.670°W Depth:20.7 km (USGS, as of October 6, 2015)
Magnitude Mw=8.3 (USGS, as of October 6, 2015)
Death Toll 13 (as of October 6, 2015)

Satellite

ALOS-2 (Advanced Land Observing Satellite 2) launched by Japan Aerospace Exploration Agency on May 24, 2014

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Contact

YARAI Hiroshi : Head of Division
KOBAYASHI Tomokazu : Chief Researcher
MORISHITA Yu : Researcher
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