The 2021 Mw 8.1 Kermadec Earthquake Sequence: Deep Megathrust Slip Nucleation and M8 Rupture along the Slab-Mantle Contact

Add to your list(s) Download to your calendar using vCal

• Lingling Ye -- Southern University of Science and Technology
• Wednesday 29 November 2023, 16:00-17:00
• Wolfson Lecture Theatre (virtual).

If you have a question about this talk, please contact Yihe Xu.

Typical plate boundary earthquakes in global subduction zone occurred along the contact between the crust in the upper plate and subducting slab. On 4 March 2021, a magnitude 8.1 earthquake struck the northern Kermadec, the largest known plate boundary event along the 1000-km long Kermadec subduction zone. It was preceded by a magnitude 7.4 foreshock at 1 hr 47 min earlier. Using teleseismic, geodetic and tsunami data, we find all substantial coseismic slip is located along the slab-mantle interface, with the foreshock nucleating near the downdip edge of the mainshock, and no significant shallow slip. Significant overlap of the slip regions between major foreshock and mainshock with a moderate number of small events occurred between them suggest a cascading faulting process. Extensive aftershocks locate updip along the slab-crust interface, which has hosted substantial prior moderate earthquake activity. The 200-km long slab-mantle interface in the northern Kermadec, the only region with major megathrust earthquakes along Kermadec subduction, has 11 M7+ deep megathrust earthquakes, including the 1976 M8 sequence. It provides a rare example of great rupture on the slab-mantle interface to understand frictional properties for olivine.

This talk is part of the Bullard Laboratories Wednesday Seminars series.

This talk is included in these lists:

• Bullard Laboratories Wednesday Seminars
• Department of Earth Sciences seminars
• Wolfson Lecture Theatre (virtual)

Note that ex-directory lists are not shown.