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.
Highlights
Magmatic intrusions and volcanic eruptions are intimately related phenomena
Magmatic injections to an erupting volcano are, in essence, short-lived intrusions whose transient overpressure stems from the competition between magma supply and conduit processes[3,11] that produce rheologically strong, lowpermeability magma that restricts the outflow of lava
We use a combination of remote sensing observations, digital terrain models (DTM) and geophysical modelling to constrain key aspects of laccolith emplacement during the 2011 explosive eruption of Cordon Caulle, Chile, the Earth’s most recently active rhyolite volcano
Summary
Magmatic intrusions and volcanic eruptions are intimately related phenomena. Shallow magma intrusion builds subsurface reservoirs that are drained by volcanic eruptions. Our results show that explosive eruptions may rapidly force significant quantities of magma in the crust to build laccoliths These iconic intrusions can be interpreted as eruptive features that pose unique and previously unrecognized volcanic hazards. Inflation and deflation cycles of silicic volcanoes[10] reflect the mechanical work done as magma rises into the edifice but becomes obstructed by highly viscous or solidified magma overhead Under these circumstances, pressures in the shallow conduit may exceed magma chamber overpressure[10], and drive renewed lava extrusion or explosive evacuation of the conduit. We use a combination of remote sensing observations, digital terrain models (DTM) and geophysical modelling to constrain key aspects of laccolith emplacement during the 2011 explosive eruption of Cordon Caulle, Chile, the Earth’s most recently active rhyolite volcano. Our results indicate that a shallow yet voluminous magmatic intrusion occurred during the early stages of explosive activity, when shallow conduit processes restricted magma output and drove elevated conduit overpressure
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
