Seismic Imaging of a Magma Chamber and Melt Recharge of the Dormant Datong Volcanoes

The Datong volcanoes erupted episodically from ca. 0.74 to ca 0.10 Ma with the last eruption at ca. 100 ka, and ever since has remained dormant. It remains elusive whether the Datong volcanoes are being recharged and would become active again in the near future. Here, we image the crustal structures beneath the Datong volcanoes using local earthquake data recorded at a newly deployed dense Datong Nodal Array. The high-resolution 3-D model reveals, for the first time, the geometry and melt fraction of a shallow crustal magma chamber at the depths of 10-20 km beneath the Datong volcanoes. Here, we suggest a magmatic system beneath the Datong volcanoes that could transport basaltic melt from the uppermost mantle to the shallow crustal magma chamber beneath the Datong volcanoes. Further, the melt-poor crustal magma chamber (melt fraction of 5%-10%) can explain why the Datong volcanoes are inactive at present, and future eruptions can be expected if melt recharge from a mantle source is sustained.