Phys.org September 13, 2024
In subduction zones, water expelled from the subducting slab is believed to be involved in seismic activity. However, little is known about its quantity and flow processes. Researchers in Japan showed that the Arima hot springs in western Japan contained high concentrations of water derived from the subducting Philippine Sea slab. A long-term record spanning over half a century revealed that the fraction of slab-derived water exhibited a temporary surge in the year preceding and/or subsequent years of the 1995 Kobe earthquake. In total, an estimated 2.6–4.2 × 105 cubic meters of slab-derived water was introduced in conjunction with the earthquake. They inferred that the earthquake was triggered by a flood-like release of water from the slab or by the bursting of clogged flow paths to the hypocenter. According to the researchers their findings highlighted the importance of hydrologically slab-connected hot springs for understanding ultradeep water cycles and their causal relationships with seismic phenomena… read more. Open Access TECHNICAL ARTICLE
Location and tectonic setting of Arima hot springs. Credit: Communications Earth & Environment volume 5, Article number: 459 (2024)