Earthquakes indicated magma viscosity during Kilauea's 2018 eruption

Roman, D. C.; Soldati, A.; Dingwell, D. B.; Houghton, B. F. und Shiro, B. R. (2021): Earthquakes indicated magma viscosity during Kilauea's 2018 eruption. In: Nature, Bd. 592, Nr. 7853: S. 237-241

Abstract

Magma viscosity strongly controls the style (for example, explosive versus effusive) of a volcanic eruption and thus its hazard potential, but can only be measured during or after an eruption. The identification of precursors indicative of magma viscosity would enable forecasting of the eruption style and the scale of associated hazards(1). The unanticipated May 2018 rift intrusion and eruption of Kilauea Volcano, Hawai'i(2) displayed exceptional chemical and thermal variability in erupted lavas, leading to unpredictable effusion rates and explosivity. Here, using an integrated analysis of seismicity and magma rheology, we show that the orientation of fault-plane solutions (which indicate a fault's orientation and sense of movement) for earthquakes preceding and accompanying the 2018 eruption indicate a 90-degree local stress-field rotation from background, a phenomenon previously observed only at high-viscosity eruptions(3), and never before at Kilauea(4-8). Experimentally obtained viscosities for 2018 products and earlier lavas from the Pu'u 'O'o vents tightly constrain the viscosity threshold required for local stress-field reorientation. We argue that rotated fault-plane solutions in earthquake swarms at Kilauea and other volcanoes worldwide provide an early indication that unrest involves magma of heightened viscosity, and thus real-time monitoring of the orientations of fault-plane solutions could provide critical information about the style of an impending eruption. Furthermore, our results provide insight into the fundamental nature of coupled failure and flow in complex multiphase systems.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Geowissenschaften > Department für Geo- und Umweltwissenschaften
• Themengebiete: 500 Naturwissenschaften und Mathematik > 550 Geowissenschaften, Geologie
• ISSN: 0028-0836
• Sprache: Englisch