Volcano-tectonic interactions at Sabancaya volcano, Peru: eruptions, magmatic inflation, moderate earthquakes, and fault creep

Abstract

for laterally and vertically complex volcanic plumbing system at Sabancaya • High fluid pressure at Sabancaya promotes strong seismicity during 2012-2019 eruptive period • High fluid pressure and static stress transfer from deep inflation promote long-lived fault creep

Shallow magma convection evidenced by excess degassing and thermal radiation during the dome-forming Sabancaya eruption (2012–2020)

“…3a), with growing VRP reaching about 0. Reath et al, 2019b;MacQueen et al, 2020) as well as by increasing VRP rising for the first time above 1 MW on 7 August 2014 (Fig. 4b).…”

“…After 15 years of quiescence, the reactivation of Sabancaya became clear in late 2012, when increased fumarolic activity was accompanied by frequent seismic swarms and deformation (Global Volcanism Program, 2013;Jay et al, 2015;Moussallam et al, 2017;Kern et al, 2017;Boixart et al, 2020;MacQueen et al, 2020) still ongoing at the time of this writing. The sequence of November 2016 explosions was followed by the extrusion of the first lava dome in more than 300 years.…”

“…Petrological and geophysical studies (Gerbe & Thouret, 2004;Jay et al, 2015;Boixart et al, 2020;MacQueen et al, 2020) suggest that the main magmatic reservoir of Sabancaya is off-centered with respect to the summit, and is located about 7 km NE (beneath Hualca Hualca) at ∼13 km depth. This reservoir is thought to be supplied by an andesitic mafic magma which causes it to inflate at a rate of 0.02-0.05 km 3 yr −1 , and destabilize regional faults (Boixart et al, 2020;MacQueen et al, 2020). Gerbe & Thouret (2004) also suggest that during the eruptive phases a shallow magma chamber (located under the Sabancaya at 6 km depth), is temporarily fed by continuous or intermittent arrival of magma from the deeper reservoir.…”

“…Gerbe & Thouret (2004) also suggest that during the eruptive phases a shallow magma chamber (located under the Sabancaya at 6 km depth), is temporarily fed by continuous or intermittent arrival of magma from the deeper reservoir. Hence, it is supposed that heat and magmatic gases from this shallow magma chamber travel along pre-existing permeable pathways in the volcanic conduit of Sabancaya, causing thermal anomalies and elevated degassing from the summit crater (Moussallam et al, 2017;Jay et al, 2015;MacQueen et al, 2020).…”

Modeling Magma System Evolution During 2006–2007 Volcanic Unrest of Atka Volcanic Center, Alaska

“…In particular, the key puzzle of the 2006–2007 volcanic unrest is whether the restless behavior occurring at central Atka triggered the phreatic eruption at Korovin, 5‐km away. A large offset (>5 km) between the deformation center and its nearest eruptive vent is not rare in the nature (Ebmeier et al., 2018), and some of the eruptions are associated with the interaction between magmatism and local fault systems, such as the Sabancaya volcano (MacQueen et al., 2020). Therefore, the Atka Volcanic Center provides an example to study the interaction between magma reservoirs, pre‐existing fault zones, and hydrothermal systems.…”