Mid-crustal fluid related to the Matsushiro earthquake swarm (1965–1967) in northern Central Japan: Geochemical reproduction

Stable isotopes show that earthquakes enhance permeability and release water from mountains

“…For instance, analysis of a long-term chemical monitoring dataset revealed post-seismic NO 3 − increase in groundwaters in recharge areas that is attributed to enhanced percolation of soil porewaters into aquifers from agricultural fields triggered by seismic vibrations 38 . The same study also revealed a post-seismic increase in the contribution of deep fluids to surface aquifers based on geochemical tracers, in particular Cl − , SO 4 2− , and B, as has been documented in many other instances [41][42][43][44][45][46] . This phenomenon occurs near the epicentre of earthquakes and in geothermal regions 38 .…”

Earthquake-induced structural deformations enhance long-term solute fluxes from active volcanic systems

“…Active volcanic areas contribute a disproportionately large component to the global flux of dissolved elements delivered from the land to the oceans, both in comparison to other lithologies 1 , 2 and to inactive volcanic systems 3 . Several processes may cause enhanced solute fluxes from active volcanic areas, including the reaction of ecosystem-recycled CO 2 with relatively young fresh mineral material 4 – 6 , volcanic acid mediated rock alteration in geothermal fields 7 – 12 , and deep, solute-rich crustal fluids released to the surface through crustal pathways 13 – 16 . These processes have distinct implications for weathering budgets and particularly for the long-term global carbon cycle.…”

“…However, the distribution, source, and discharge mechanism of deep fluids, and their impact on watershed hydrochemistry and long-term lateral weathering fluxes, are not well understood in the global context because of limited study opportunities. Earthquakes can trigger an increase in dissolved geochemical fluxes 13 – 20 partly by opening new pathways for deep fluid discharge to the surface 13 – 16 . Even though active volcanism is sometimes accompanied by seismotectonic processes that may systematically facilitate the release of solute-rich deep fluids 21 , 22 , the role of seismotectonic processes in sustaining the high apparent weathering fluxes from volcanic systems is not known.…”