Speaker: Taiyi Wang, Assistant Professor, University of Texas at Austin Jackson School for Geosciences

Title: Cascading magmatic unrest and aseismic faulting in the Aegean Sea enabled by elastic stress relay

Host: Zhe Jia

Abstract: Magma reservoirs commonly exist in clusters and situate within complex fault networks, yet sequential triggering of unrest at multiple reservoirs and faults is rarely observed. In this talk, I will show that the 2025 earthquake swarm in the Christiana-
Santorini-Kolumbo complex of the Aegean Sea was driven by elastic stress transfer between two magma reservoirs, a 9-km-long dike, and a 17-km-long, southeast-dipping fault. Pressurization of the magma reservoir under Santorini triggered a dike intrusion originating from a separate magma reservoir under the Kolumbo volcano. The dike, in turn, triggered a Mw6.2 aseismic slip transient on a SW-NE trending branch of the Amorgos fault. Episodic bursts of upward-propagating
seismicity within the geodetically constrained dike potentially indicate buoyancy- driven, segmented dike opening.

Our work suggests that unrest in rift zones can propagate over spatial scales much larger than individual magma reservoirs and faults via sequential relay of elastic stress.