The 2022 Taiwan Earthquake: Crustal deformation detected by ALOS-2 data

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Released: Oct. 6, 2022, Japanese version of this page

Summary

M6.5 and M6.9 (USGS) earthquakes occurred in Taiwan on September 17, 2022 and September 18, 2022 (UTC), respectively. To measure the crustal deformation caused by this earthquake, we applied interferometric analysis using ALOS-2/PALSAR-2 data. The analysis clearly revealed the spatial distribution of crustal deformation.

Crustal deformation is observed along the Longitudinal Valley Fault and the Central Range Fault. (Figures 1 and 2)
Crustal deformation is larger on the west side of the fault zone compared to that on the east side. (Figures 1, 2)
In some areas in the proximity of the above fault zone, incoherent phases are observed. The ground surface may have been altered by seismic activity in these areas. (Figure 3)
A crustal deformation reaching 1 m was observed in the direction of approaching satellite.

InSAR pair

Fig. #	Date	Time (UTC)	Flight Dir.	Beam Dir.	Obs. Mode *1	Incidence Angle (around epicenter)	Bperp
1	2022-08-07 2022-09-18	16:11	Asc.	Right	W-W (490km)	55.1°	-170m
2	2022-05-19 2022-09-20	15:57	Asc.	Right	F-F (10m)	38.0°	72m

*1 F: Stripmap (Fine), W:ScanSAR(Wide)
(cf. ALOS-2 Project / PALSAR-2 (JAXA))

SAR Interferograms

2022-09-18INSARimage

Fig. 1 SAR interferogram [PNG: 1MB]
Fault lines are based on Styron et al. (2010).

2022-09-22INSARimage

Fig. 2 SAR interferogram [PNG: 1MB]
Fault lines are based on Styron et al. (2010).

2022-09-22INSARimage

Fig. 3 an enlarged view of part of Fig. 2. [PNG: 1MB]
Fault lines are based on Styron et al. (2010).

range

Fig. 4 range

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

The 2022 Taiwan Earthquake

Date-Time	Sep. 17, 2022, 13:41(UTC)
Hypocenter Location	23.096°N, 121.406°E, Depth:10.0km (USGS, as of Oct. 3, 2022)
Magnitude	M=6.5 (USGS, as of Oct. 3, 2022)

Date-Time	Sep. 18, 2022, 06:44(UTC)
Hypocenter Location	23.159°N, 121.316°E, Depth:10.0km (USGS, as of Oct. 3, 2022)
Magnitude	M=6.9 (USGS, as of Oct. 3, 2022)

Satellite

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

Copyrights and Credits

Contact

Geography and Crustal Dynamics Research Center
Crustal Deformation Research
MUNEKANE Hiroshi: Head of Division