Last Updated : May 10, 2024

The 2024 Taiwan Earthquake: Crustal deformation detected by ALOS-2 data

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Released: Apr. 5, 2024, update: Apr. 17 2024, update: May 10 2024 Japanese version of this page

Summary

M7.7 (Japan Meteorological Agency; JMA) earthquake occurred in Taiwan on April 2, 2024 (UTC). 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 from the Milun Fault to the northern part of the Longitudinal Valley Fault. According to the 2.5-Dimensional analysis, maximum deformation reached 50 cm.

InSAR pair

Pair Fig.
#		 Date Time
(UTC)		 Flight
Dir.		 Beam
Dir.		 Obs.
Mode *1		 Incidence Angle
(around epicenter)		 Bperp
Pair1 4,5 2023-10-19
2024-04-04		 15:57 Asc. Right F-F
(10m)		 40.7° +291m
Pair2 6,7 2024-03-08
2024-04-05		 03:55 Des. Right W-W
(350km)		 26.8° +132m
Pair3 8 2024-01-29
2024-04-07		 04:36 Des. Left W-W
(350km)		 54.5° -17m

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

2.5-Dimensional analysis

20240404INSAR画像

Fig. 1 Quasi-vertical Displacement
from the combination of Pair1 and Pair2 [PNG: 765KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

20240404INSAR画像

Fig. 2 Quasi-east-west Displacement
from the combination of Pair1 and Pair2 [PNG: 823KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

2.5次元解析によりもとまった変位断面

Fig. 3 The cross-section of 2.5D displacement distribution along line A-B.
Fault location, strike, and dip are based on USGS CMT solution. [PNG: 43KB]
The fault plane is shown as an east-dipping fault with 40 km long and 25 km wide,
based on the USGS slip distribution solution.

SAR Interferograms

20240404INSAR画像

Fig. 4 SAR interferogram [PNG: 984KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

20240404INSAR画像

Fig. 5 SAR interferogram (Unwrapped) [PNG: 777KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

20240405INSAR画像

Fig. 6 SAR interferogram [PNG: 947KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

20240405INSAR画像

Fig. 7 SAR interferogram (Unwrapped) [PNG: 567KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

20240407INSAR画像

Fig. 8 SAR interferogram [PNG: 1MB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

解析範囲

Fig. 9 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 2024 Taiwan Earthquake

Date-Time Apr. 2, 2024, 23:58(UTC)
Hypocenter
Location		 23.83°N, 121.60°E, Depth:23km
(JMA, as of Apr. 16, 2024)
Magnitude M=7.7
(JMA, as of Apr. 16, 2024)

Satellite

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

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Contact

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

Links

[Reference information] Analysis results on April 17, 2024

Summary

M7.7 (Japan Meteorological Agency; JMA) earthquake occurred in Taiwan on April 2, 2024 (UTC). 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 from the Milun Fault to the northern part of the Longitudinal Valley Fault. Maximum deformation reached 45 cm in the line-of-sight direction of the satellite.

SAR Interferograms

20240404INSAR画像

Fig. 1 SAR interferogram [PNG: 995KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

20240404INSAR画像

Fig. 2 SAR interferogram (Unwrapped) [PNG: 791KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

20240405INSAR画像

Fig. 3 SAR interferogram [PNG: 847KB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

20240405INSAR画像

Fig. 4 SAR interferogram (Unwrapped) [PNG: 282KB]
Epicenter is JMA. Fault lines are based on Styron et al. (2020).

20240407INSAR画像

Fig. 5 SAR interferogram [PNG: 1MB]
Epicenter is from JMA. Fault lines are based on Styron et al. (2020).

range

Fig. 6 range

InSAR pair and The 2024 Taiwan Earthquake (Sourced by CWA)

Pair Fig.
#		 Date Time
(UTC)		 Flight
Dir.		 Beam
Dir.		 Obs.
Mode *1		 Incidence Angle
(around epicenter)		 Bperp
Pair1 1,2 2023-10-19
2024-04-04		 15:57 Asc. Right F-F
(10m)		 40.7° +291m
Pair2 3,4 2024-03-08
2024-04-05		 03:55 Des. Right W-W
(350km)		 26.8° +132m
Pair3 5 2024-01-29
2024-04-07		 04:36 Des. Left W-W
(350km)		 54.5° -17m

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

Date-Time Apr. 2, 2024, 23:58(UTC)
Hypocenter
Location		 23.83°N, 121.60°E, Depth:23km
(JMA, as of Apr. 16, 2024)
Magnitude M=7.7
(JMA, as of Apr. 16, 2024)

[Reference information] Analysis results on April 5, 2024

Summary

M7.2 (Central Weather Administration; CWA) earthquake occurred in Taiwan on April 2, 2024 (UTC). 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 from the Milun Fault to the northern part of the Longitudinal Valley Fault. Maximum deformation reached 45 cm in the line-of-sight direction of the satellite.

SAR Interferograms

20240404INSAR画像

Fig. 1 SAR interferogram [PNG: 1014KB]
Epicenter and aftershock distribution are from CWA. Fault lines are based on Styron et al. (2020).

20240404INSAR画像

Fig. 2 SAR interferogram (Unwrapped) [PNG: 791KB]
Epicenter and aftershock distribution are from CWA. Fault lines are based on Styron et al. (2020).

range

Fig. 3 range

The 2024 Taiwan Earthquake (Sourced by CWA)

Date-Time Apr. 2, 2024, 23:58(UTC)
Hypocenter
Location		 23.77°N, 121.66°E, Depth:15.5km
(CWA, as of Apr. 5, 2024)
Magnitude M=7.2
(CWA, as of Apr. 5, 2024)

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