Tsunami Genesis of Strike-Slip Earthquakes Revealed in the 2018 Indonesian Palu Event

Song, Y. Tony1; Chen, Kejie2,3; Prasetya, Gegar4

2023-05-01

10.1007/s00024-023-03295-x

PURE AND APPLIED GEOPHYSICS   影响因子和分区

0033-4553

1420-9136

The devastating tsunami after the 2018 Indonesian Sulawesi-Palu strike-slip earthquake was a surprise because strike-slip faulting was a known phenomenon of primarily lateral movement of land, while tsunamis were believed to be caused by vertical movements of seafloor or landslides. Here we demonstrated how the strike-slip faulting could have pushed waters from outside and inside the Palu Bay to form a powerful tsunami in the Palu Bay. We constructed three earthquake inversions from seismographs, satellite radar and optical imagery, and used an open-source ocean circulation model to replicate the tsunami. Our experiments revealed that: (1) the southward horizontal displacement of deeper-water slopes along the Makassar coast generated a long-wave tsunami of 40 km, propagating southward into the Palu Bay and consisting with the two distinguished tsunami-peaks in the Pantoloan tide-record, twice higher than the local resonance waves; (2) the two types of tsunamis in the Mamuju tide-record-the "early arrival" tsunami and the late larger tsunami-were originated from the outside and inside sources; and (3) the eyewitness account of the whirlpool circulation in the Palu Bay could be explained by the horizontal strike-slip forcing of the two involved tectonic plates. The east plate was largely responsible for pushing the long-wave tsunami southward that inundated the Palu City and resulted in the devastation. Our findings suggest that the tsunami's behavior of strike-slip earthquakes is more complex than previously thought and should be considered in future tsunami early warnings.

Tsunami genesis formation mechanism strike-slip earthquake seismic inversion

SCI ; EI

英语

其他

National Science Foundation of China[42074024]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000990948200001

SPRINGER BASEL AG

20232114125493

Earthquakes ; Fault slips ; Satellite imagery ; Strike-slip faults

Seawater, Tides and Waves:471.4 ; Seismology:484 ; Earthquake Measurements and Analysis:484.1 ; Satellites:655.2

GEOSCIENCES

Web of Science

1.CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA
2.CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA
3.Southern Univ Sci & Technol, Dept Earth & Space Sci, Shenzhen 518055, Peoples R China
4.Tsunami Res Fdn Indonesia, Indonesian Tsunami Soc IATsI, Yogyakarta, Indonesia

Song, Y. Tony,Chen, Kejie,Prasetya, Gegar. Tsunami Genesis of Strike-Slip Earthquakes Revealed in the 2018 Indonesian Palu Event[J]. PURE AND APPLIED GEOPHYSICS,2023,180(6):1909-1923.

Song, Y. Tony,Chen, Kejie,&Prasetya, Gegar.(2023).Tsunami Genesis of Strike-Slip Earthquakes Revealed in the 2018 Indonesian Palu Event.PURE AND APPLIED GEOPHYSICS,180(6),1909-1923.

Song, Y. Tony,et al."Tsunami Genesis of Strike-Slip Earthquakes Revealed in the 2018 Indonesian Palu Event".PURE AND APPLIED GEOPHYSICS 180.6(2023):1909-1923.