Did A M5.3 Kilauea EQ In 2017 Influence The 2018 Eruption?

A seismology team, including scientists from USGS-HVO, have revealed an interesting potential link going back from the legendary 2018 eruption back to a magnitude 5.3 that occurred in June, 2017. The research article looks at south flank earthquake that preceded the May 4th, 2018 M6.9 earthquake, and how after the 2017 earthquake altered the seismic velocity throughout the volcano afterwards. The change could have then lead to an increase in pressure and stress in the system, with the greatest effect near Pu‘u ‘Ō‘ō, until magma intruded down rift and into the legendary 2018 eruption. AUTHORS: Ashton F. Flinders, Corentin Caudron, Ingrid A. Johanson, Taka’aki Taira, Brian Shiro, and Matthew Haney PAPER ABSTRACT: The 2018 lower East Rift Zone eruption of Kīlauea (Hawai‘i) marked a dramatic change in the volcano’s 35-year-long rift zone eruption. The collapse of the middle East Rift Zone vent Pu‘u ‘Ō‘ō was followed by one of the volcano’s most voluminous eruptions in 500 years. Over the course of this 3-month eruption, the draining of summit-stored magma led to near-daily collapses of a portion of the caldera and ultimately up to 500 m of summit subsidence. While deformation data indicated that the summit and middle East Rift Zone were inflating for the previous several years, why Pu‘u ‘Ō‘ō collapsed and what initiated down-rift dike propagation remains unclear. Using ambient noise seismic interferometry, we show that a Ml5.3 decollement earthquake beneath Kīlauea’s south flank in June 2017 induced a coseismic decrease of up to 0.30% in seismic velocity throughout the volcano. This velocity decrease may have been caused by dynamic stress–induced shallow crustal fracture, i.e., weakening to dilatant crack growth, and was greatest near Pu‘u ‘Ō‘ō. Additionally, we verify a pre-eruptive increase in seismic velocity, consistent with increasing pressurization in the volcano’s shallow summit magma reservoir. This velocity increase occurred coincident with the first in a series of lower-crustal earthquake swarms, 6 days before a 2-month period of rapid summit and middle East Rift Zone inflation. The increase in up-rift magma-static pressure, combined with the pre-existing weakness from the June 2017 earthquake, may have facilitated down-rift dike propagation and the devastating 2018 eruption. Full Research Article: https://link.springer.com/article/10.1007/s00445-020-01380-w