The rupture process of 2018 Mw 7.0 Kalapana, Hawaii earthquake and relation with the 1975 event

Jinlai Hao, Wenze Deng, & Chen Ji

Submitted August 15, 2018, SCEC Contribution #8679, 2018 SCEC Annual Meeting Poster #285

The Mw 7.0 2018 Kalapana, Hawaii earthquake struck the south flank of Kilauea volcano, Hawaii Island, on May 4th 2018, a day after the starting of the 2018 Lower Puna eruption. Its epicenter was a few km away from the epicenter of 1975 Mw 7.7 earthquake, outside the southeast coast of Hawaii island. The relations with previous event and new eruption drew our attention. Here we constrain the rupture process of the Kalapana earthquake by joint inverting the GPS static displacements, waveforms of local strong motion, teleseismic P and SH waves, and long period surface waveforms. Our preliminary study reveals that the rupture occurred on a low angle fault plane dipping 9 degree north-northwest, and broke a fault patch 35 km along strike and 20 km downdip, with an average slip of 1.2 m. The inverted rupture duration time and total moment of our preferred model are 22.4 s and 4.3x10**19 Nm (Mw 7.0), respectively. The centroid was located at about 7.2 km southwest of the hypocenter in a depth of 6.6 km. The rupture propagation is about 1.2 km/s along strike but much slower downdip. We will compare the rupture characterizations of 1975 and 2018 Kalapana earthquakes and investigate the impact of this earthquake to the 2018 Lower Puna eruption.

Citation
Hao, J., Deng, W., & Ji, C. (2018, 08). The rupture process of 2018 Mw 7.0 Kalapana, Hawaii earthquake and relation with the 1975 event. Poster Presentation at 2018 SCEC Annual Meeting.


Related Projects & Working Groups
Seismology