Rapid laccolith intrusion driven by explosive volcanic eruption

Abstract

Magmatic intrusions and volcanic eruptions are intimately related phenomena. Shallow magma intrusion builds subsurface reservoirs that are drained by volcanic eruptions. Thus, the long-held view is that intrusions must precede and feed eruptions. Here we show that explosive eruptions can also cause magma intrusion. We provide an account of a rapidly emplaced laccolith during the 2011 rhyolite eruption of Cordón Caulle, Chile. Remote sensing indicates that an intrusion began after eruption onset and caused severe (>200 m) uplift over 1 month. Digital terrain models resolve a laccolith-shaped body ∼0.8 km3. Deformation and conduit flow models indicate laccolith depths of only ∼20–200 m and overpressures (∼1–10 MPa) that likely stemmed from conduit blockage. Our results show that explosive eruptions may rapidly force significant quantities of magma in the crust to build laccoliths. These iconic intrusions can thus be interpreted as eruptive features that pose unique and previously unrecognized volcanic hazards.

MMASTER: Improved ASTER DEMs for Elevation Change Monitoring

“…The topographic pattern displays: (1) a sub-circular feature of 200-250 m in amplitude, which corresponds to a combination of surface bulging due to the shallow laccolith emplacement and deposition of erupted materials, and (2) an elongated, relatively flat feature of 125 m in amplitude, which corresponds to the rhyolitic lava flow. The topography difference calculated with MMASTER shows the same patterns as that described by [30], computed using the ASTER GDEMv2 and a Pleiades DEM.…”

Syn-Emplacement Fracturing in the Sandfell Laccolith, Eastern Iceland—Implications for Rhyolite Intrusion Growth and Volcanic Hazards

“…As the feeder of the Sandfell laccolith is not exposed, we constrain time scales of intrusion by using average extrusion rates of observed intrusive and extrusive dome building eruptions (1-10 m 3 /s, Newhall and Melson, 1983;Sparks et al, 1998) and estimated effusion rates of Icelandic dike-fed rhyolitic eruptions (1-10 m 3 /s, Höskuldsson and Sparks, 1997;Tuffen and Castro, 2009). Notably, the Cordón Caulle laccolith that was related to an ongoing eruption had a mean intrusion rate of ∼300 m 3 /s (Castro et al, 2016). Intrusion rates of 300, 10, and 1 m 3 /s would fill the 0.57 km 3 Sandfell laccolith in about 22 days, 22 months, and 18 years, respectively.…”

“…Laccolith/cryptodome intrusion events have been documented at Mt. St. Helens, USA, Córdon Caulle, Chile, and Usu, Japan, where intrusion time scales range from a month to approximately a year (Minakami et al, 1951;Lipman et al, 1981;Castro et al, 2016). The geological record and geochronology of exposed laccoliths also display incremental growth histories ranging over thousands of years (e.g., Michel et al, 2008).…”

Unravelling intrusion-induced forced fold kinematics and ground deformation using 3D seismic reflection data

“…Ground deformation driven by intrusion-induced forced folding is akin to the up- lift observed at active volcanoes generated by magma movement and accumulation [e.g. Castro et al 2016;Magee et al 2017a]. Given the broad spatial coincidence between fold outlines and sill terminations (e.g.…”