Last Updated : September 2, 2016

The August 2016 Central Italy Earthquake: Crustal deformation detected by ALOS-2 data

Crustal Deformation Observed by Synthetic Aperture Radar (SAR)

Released: Aug. 26, 2016, Last Updated: Sep. 2, 2016 Japanese version of this page

Crustal Deformation revealed by InSAR

An earthquake (Mw 6.2 USGS) occurred in central Italy on August 24, 2016. It caused serious damage on human lives and buildings around the epicentral area. We applied interferometric analysis using ALOS-2/PALSAR-2 data to measure the crustal deformation caused by the earthquake.

The result obtained from the data acquired by August 31, 2016 is summarized as follows.
  • The interferograms (Fig. 1 and 2) show displacement away from the satellite around the epicenter.
  • The quasi up-down component of the displacement (Fig. 3) shows subsidence around the epicenter. The maximum subsidence reaches about 20 cm around Accumoli. The quasi east-west component of the displacement (Fig. 4) shows about 20 cm westward displacement at the eastern area of the subsiding area. Fig. 4 also shows a few cm eastward and westward displacement at east side and west side of the subsiding area, respectively.
  • The area with the subsidence of over 5 cm covers from east of Norcia to near Amatrice, about 20 km in NNW-SSE direction, and it implies the length of the earthquake fault.
  • There is a gap line of displacement with the length of 5 km in the northeast of the deforming area, which may represent a surface rupture.
  • The features of the displacement are consistent with a normal fault motion with the strike of NNW-SSE direction.

* Note that the result is possibly updated with further elaborated analyses.

cf. At the south of the epicenter, an earthquake (M6.3) occurred on April 6, 2009, around L'Aquila. Its displacement was also measured by ALOS/PALSAR data (see link below).


Click the images below to enlarge.

Fig. 1 Ascending interferogram

Fig. 1 [PNG: 1.38MB]

Fig. 2 Descending interferogram

Fig. 2 [PNG: 1.30MB]


Date Time
Bperp KMZ
1 2015-09-09
23:00 Asc. Right F-F 41° +199m 4.23MB
2 2016-05-25
11:15 Des. Right F-F 36° -88m 2.43MB

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

Analyzed 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.

Quasi up-down and east-west components of displacement

Click the images below to enlarge.

Fig3 up-down

Fig. 3. Quasi up-down component [PNG: 1.38MB] [KMZ: 0.99MB]

Fig4 east-west

Fig. 4. Quasi east-west component [PNG: 1.30MB] [KMZ: 1.16MB]


2.5-D analysis
Two or more line-of-sight displacements with different observing directions can be decomposed to quasi up-down and east-west components.


The August 2016 Central Italy Earthquake

Date-Time August 24, 2016 3:36 (Local time), 1:36 (UTC)
42.707°N, 13.176°E, Depth: 10.0 km (USGS, as of September 2, 2016)
Magnitude Mw=6.2 (USGS, as of September 2, 2016)
Death Toll 294 (as of September 2, 2016)


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

Paper, Report, Presentation

In preparation

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