Mechanisms of Unrest and Eruption at Persistently Restless Volcanoes: Insights From the 2015 Eruption of Telica Volcano, Nicaragua
Artikel i vetenskaplig tidskrift, 2019

Many of Earth's volcanoes experience well-defined states of “quiescence” and “unrest,” with unrest occasionally culminating in eruption. Some volcanoes, however, experience an unusually protracted (i.e., decades-long) period of noneruptive unrest and are thus categorized as “persistently restless volcanoes” (PRVs). The processes that drive persistently restless volcanism are poorly understood, as our knowledge of PRVs is currently based on a small number of case studies. Here we examine multidisciplinary observations of the 2015 eruptive episode at Telica Volcano, Nicaragua, in the context of its long-term behavior. We suggest that the latter phases of the 2015 eruption were ultimately driven by destabilization of its shallow magma reservoir. Based on previous geodetic-seismic studies of Telica (Geirsson et al., 2014, https://doi.org/10.1016/j.jvolgeores.2013.11.009; Rodgers et al., 2013, https://doi.org/10.1016/j.jvolgeores.2013.08.010 and 2015, https://doi.org/10.1016/j.jvolgeores.2014.11.012) and on multiparameter observations at Telica over a 7-year period, we propose that three distinct states of unrest occur at Telica over decadal timescales: a stable open state involving steady conduit convection and two distinct “unstable” states that may lead to eruptions. In the “weak sealing” state, phreatic explosions result from steady conduit convection underlying a weak seal. In the “destabilized” state, destabilization of the top of the convecting magma in the conduit leads to rapid accumulation of high pressures leading to strong/impulsive phreatomagmatic explosions. Our observations and interpretations suggest that continuous seismic, ground-based deformation, gas emission, and thermal monitoring and interpretation of these data within a paradigm of sustained conduit convection modulated by episodes of sealing and destabilization of shallow magma reservoirs may allow robust forecasting of eruption potential, energy, and duration at Telica and similar PRVs worldwide.

long-term unrest

Telica Volcano

phreatic eruptions

Författare

Diana Roman

Department of Terrestrial Magnetism Carnegie Institution of Washington

Peter LaFemina

Pennsylvania State University

Rebecca Bussard

Pennsylvania State University

Kirsten Stephens

Pennsylvania State University

Christelle Wauthier

Pennsylvania State University

Machel Higgins

Pennsylvania State University

Maureen Feineman

Pennsylvania State University

Santiago Arellano

Chalmers, Rymd-, geo- och miljövetenskap, Mikrovågs- och optisk fjärranalys

J. Maarten De Moor

Universidad Nacional de Costa Rica

Geoffroy Avard

Universidad Nacional de Costa Rica

Maria Martinez

Universidad Nacional de Costa Rica

Mike Burton

University of Manchester

Matthew Varnam

University of Manchester

Armando Saballos

Instituto Nicaragüense de Estudios Territoriales

Martha Ibarra

Instituto Nicaragüense de Estudios Territoriales

Wilfried Strauch

Instituto Nicaragüense de Estudios Territoriales

Virginia Tenorio

Instituto Nicaragüense de Estudios Territoriales

Geochemistry, Geophysics, Geosystems

1525-2027 (ISSN)

Vol. 20 8 4162-4183

Fundament

Grundläggande vetenskaper

Ämneskategorier

Geofysik

Geologi

Geokemi

DOI

10.1029/2019GC008450

Mer information

Senast uppdaterat

2019-10-30