scholarly journals Phreatic eruptions at crater lakes: occurrence statistics and probabilistic hazard forecast

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Karen Strehlow ◽  
Laura Sandri ◽  
Joachim H. Gottsmann ◽  
Geoff Kilgour ◽  
Alison C. Rust ◽  
...  
Keyword(s):  
Crater Lakes ◽  
Phreatic Eruptions

scholarly journals Response of a Hydrothermal System to Escalating Phreatic Unrest the Case of Turrialba and Irazú in Costa Rica (2007-2012)

2021 ◽  
Author(s):  
Dmitri Rouwet ◽  
Raul Mora-Amador ◽  
Carlos Ramirez ◽  
Gino González-Ilama ◽  
Eleonora Baldoni ◽  
...  
Keyword(s):  
Costa Rica ◽  
Hydrothermal System ◽  
Crater Lake ◽  
Removal Rate ◽  
Summit Crater ◽  
Hydrothermal Systems ◽  
Thermal Springs ◽  
Total Output ◽  
Crater Lakes ◽  
Phreatic Eruptions

Abstract This study presents the first hydrogeochemical model of the hydrothermal systems of Turrialba and Irazú volcanoes in central Costa Rica, manifested as thermal springs, summit crater lakes, and fumarolic degassing at both volcanoes. Our period of observations (2007-2012) coincides with the pre- and early syn-phreatic eruption stages of Turrialba volcano that resumed volcanic unrest since 2004, after almost 140 years of quiescence. Peculiarly, the generally stable Irazú crater lake dropped its level during this reawakening of Turrialba. The isotopic composition of discharged fluids reveals the Caribbean meteoric origin; a contribution of “andesitic water” for Turrialba fumaroles up to ~50% is suggested. Four groups of thermal springs drain the northern flanks of Turrialba and Irazú volcanoes into two main rivers. Río Sucio (i.e. “dirty river”) is a major rock remover on the North flank of Irazú, mainly fed by the San Cayetano spring group. Instead, one group of thermal springs discharges towards the south of Irazú. All thermal spring waters are of SO4-type (i.e. steam heated waters), although none of the springs has a common hydrothermal end-member. A water mass budget for thermal springs results in an estimated total output flux of 187 ± 37 L/s, with 100 ± 20 L/s accounted for by the San Cayetano springs. Thermal energy release is estimated at 110 ± 22 MW (83.9 ± 16.8 MW by San Cayetano), whereas the total rock mass removal rate by chemical leaching is ~3,000 m3/y (~2,400 m3/y by San Cayetano-Río Sucio). Despite Irazú being the currently less active volcano, it is a highly efficient rock remover, which, on the long term can have effects on the stability of the volcanic edifice with potentially hazardous consequences (e.g. flank collapse, phreatic eruptions). Moreover, the vapor output flux from the Turrialba fumaroles after the onset of phreatic eruptions on 5 January 2010 showed an increase of at least ~260 L/s above pre-eruptive background fumarolic vapor fluxes. This extra vapor loss implies that the drying of the summit hydrothermal system of Turrialba could tap deeper than previously thought, and could explain the coincidental disappearance of Irazú’s crater lake in April 2010.

scholarly journals Groundwater Interacting at Depth With Hot Plastic Magma Triggers Phreatic Eruptions at Yugama Crater Lake of Kusatsu-Shirane Volcano (Japan)

2021 ◽  
Vol 9 ◽  
Author(s):  
Muga Yaguchi ◽  
Takeshi Ohba ◽  
Akihiko Terada
Keyword(s):  
Crater Lake ◽  
The Self ◽  
Ratio Increase ◽  
Rock Interaction ◽  
Crater Lakes ◽  
Magmatic Fluids ◽  
Plastic Rock ◽  
Sealing Zone ◽  
Phreatic Eruptions ◽  
Ph Decrease

Interpreting the triggering mechanisms for phreatic eruptions is a key to improving the hazard assessment of crater lakes. Yugama Crater Lake at Kusatsu-Shirane volcano, Japan, is the site of frequent phreatic eruptions with the recent eruptions in 1982–83, 1989, and 1996, as well as volcanic unrest, including earthquake swarms in 2014 and 2018. To understand the magma–hydrothermal interaction beneath Yugama Crater Lake, we analyzed lake waters from November 2005 to May 2021. From 2005 to 2012, Cl and SO4 concentrations decreased slowly, suggesting the development of a self-sealing zone surrounding the crystallizing magma. We focused on Ca, Al, and Si concentrations as representatives of the breach and dissolution of minerals comprising the self-sealing zone and the Mg/Cl ratio as an indicator for enhanced interaction between groundwater and hot plastic rock within the self-sealing zone. In 2006–2007, the Ca, Al, Si concentrations and the Mg/Cl ratio increased. No Cl and SO4 increase during this period suggests the self-sealing zone was leached by deep circulating groundwater rather than by magmatic fluids injection. After the 2014 earthquakes, Ca, Al, and Si increased again but were associated with a significant Cl increase and a pH decrease. We believe that the HCl-rich magmatic fluids breached the self-sealing zone, leading to fluids injection from the crystallizing magma to the Yugama crater. During this period, the Mg/Cl ratio did not increase, meaning that magmatic fluids ascending from the breached area of the self-sealing zone inhibited deep intrusion of groundwater into the hot plastic rock region. In 2018, magmatic fluids ascended through the self-sealing zone again with less intensity than in 2014. All eruptions since 1982 have been accompanied by a Mg/Cl ratio increase and a Cl decrease, whereas, when a significant HCl input occurs, as in 2014, no eruptions and no Mg/Cl ratio increase occurred. This demonstrates that the groundwater–hot plastic rock interaction, rather than the magmatic fluids input, played an essential role in triggering phreatic eruptions; i.e., phreatic eruptions can potentially occur without clear signs of fresh magma intrusions.

scholarly journals Response of a hydrothermal system to escalating phreatic unrest: the case of Turrialba and Irazú in Costa Rica (2007–2012)

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
D. Rouwet ◽  
R. Mora-Amador ◽  
C. Ramírez ◽  
G. González ◽  
E. Baldoni ◽  
...  
Keyword(s):  
Costa Rica ◽  
Hydrothermal System ◽  
Crater Lake ◽  
Removal Rate ◽  
Summit Crater ◽  
Hydrothermal Systems ◽  
Thermal Springs ◽  
Total Output ◽  
Crater Lakes ◽  
Phreatic Eruptions

AbstractThis study presents the first hydrogeochemical model of the hydrothermal systems of Turrialba and Irazú volcanoes in central Costa Rica, manifested as thermal springs, summit crater lakes, and fumarolic degassing at both volcanoes. Our period of observations (2007–2012) coincides with the pre- and early syn-phreatic eruption stages of Turrialba volcano that resumed volcanic unrest since 2004, after almost 140 years of quiescence. Peculiarly, the generally stable Irazú crater lake dropped its level during this reawakening of Turrialba. The isotopic composition of all the discharged fluids reveals their Caribbean meteoric origin. Four groups of thermal springs drain the northern flanks of Turrialba and Irazú volcanoes into two main rivers. Río Sucio (i.e. “dirty river”) is a major rock remover on the North flank of Irazú, mainly fed by the San Cayetano spring group. Instead, one group of thermal springs discharges towards the south of Irazú. All thermal spring waters are of SO4-type (i.e. steam-heated waters), none of the springs has, however, a common hydrothermal end-member. A water mass budget for thermal springs results in an estimated total output flux of 187 ± 37 L/s, with 100 ± 20 L/s accounted for by the San Cayetano springs. Thermal energy release is estimated at 110 ± 22 MW (83.9 ± 16.8 MW by San Cayetano), whereas the total rock mass removal rate by chemical leaching is ~ 3000 m3/year (~ 2400 m3/year by San Cayetano-Río Sucio). Despite Irazú being the currently less active volcano, it is a highly efficient rock remover, which, on the long term can have effects on the stability of the volcanic edifice with potentially hazardous consequences (e.g. flank collapse, landslides, phreatic eruptions). Moreover, the vapor output flux from the Turrialba fumaroles after the onset of phreatic eruptions on 5 January 2010 showed an increase of at least ~ 260 L/s above pre-eruptive background fumarolic vapor fluxes. This extra vapor loss implies that the drying of the summit hydrothermal system of Turrialba could tap deeper than previously thought, and could explain the coincidental disappearance of Irazú’s crater lake in April 2010.

GEOCHEMISTRY OF TWO CRATER LAKES: THE NEWBERRY CALDERA, OREGON

2016 ◽  
Author(s):  
Samuel Caldwell ◽  
◽  
Anna Martini ◽  
Johan C. Varekamp
Keyword(s):  
Crater Lakes

Fracture network mapping using remote sensing in three crater lakes environments of the Cameroon volcanic line (central Africa)

2021 ◽  
Vol 14 (6) ◽  
Author(s):  
Marthe Mbond Ariane Gweth ◽  
Jorelle Larissa Meli’i ◽  
Valentin Oyoa ◽  
Diab Ahmad Diab ◽  
Daniel Herve Gouet ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Central Africa ◽  
Fracture Network ◽  
Crater Lakes ◽  
Cameroon Volcanic Line ◽  
Network Mapping

Crater lakes of the Pali Aike Volcanic Field as key sites for paleoclimatic and paleoecological reconstructions in southern Patagonia, Argentina

2006 ◽  
Vol 21 (3) ◽  
pp. 294-309 ◽  
Author(s):  
Bernd Zolitschka ◽  
Frank Schäbitz ◽  
Andreas Lücke ◽  
Hugo Corbella ◽  
Bettina Ercolano ◽  
...  
Keyword(s):  
Volcanic Field ◽  
Crater Lakes ◽  
Southern Patagonia ◽  
Key Sites ◽  
Paleoecological Reconstructions

Diffuse CO2 flux emission in two maar crater lakes from São Miguel Island (Azores, Portugal)

2019 ◽  
Vol 369 ◽  
pp. 188-202 ◽  
Author(s):  
César Andrade ◽  
Fátima Viveiros ◽  
J. Virgílio Cruz ◽  
Rafael Branco ◽  
Lucía Moreno ◽  
...  
Keyword(s):  
Co2 Flux ◽  
Crater Lakes

Some physical and chemical features of two upland crater lakes in tropical north-eastern Australia

1999 ◽  
Vol 50 (2) ◽  
pp. 159 ◽  
Author(s):  
D. Walker
Keyword(s):  
Thermal Stability ◽  
Meteorological Data ◽  
Euphotic Zone ◽  
Open Water ◽  
Crater Lakes ◽  
Ground Temperatures ◽  
Eastern Australia ◽  
North Eastern ◽  
Physical And Chemical ◽  
Continuous Deposition

Lakes Barrine and Eacham, ~1.0 and 0.5 km2 area, 67 and 63 m depth respectively, lie at ~740 m a.s.l., ~17°S in north-eastern Australia. Seasonal changes in their volumes modelled from meteorological data correspond well with observations at Eacham. Temperature profiles through 6 years show summer stratification with a metalimnion at 20–30 m; in winter, near isothermy is usually attained. At Barrine, thermal stability varies between winter and summer (<500 and >4000 g-cm cm-2 respectively). Mixing is related to low ground temperatures during periods of generally low thermal stability; exceptionally it penetrates to >60 m. Oxygen saturation decreases from the surface to ~20% at the base of the euphotic zone (15–21 m) but oxygen is carried lower by mixing after which anoxia commonly rises to ~40 m. At Barrine, Fe-reducing redox (<200 mV) usually occurs below 50 m, but during mixing this boundary falls to within 1 m of the mud–water interface. The Barrine solution is dilute (total dissolved solids 55–58 mg L-1), and that of Eacham is more so. A concentrated monimolimnion has developed in the lowermost 2–3 m at Barrine but not at Eacham. Sedimentation at the middle of each lake results from the continuous deposition of open-water products punctuated by the redistribution of coarser detritus from the ‘shallows’ at times of deep mixing. The resultant laminations are preserved only at Barrine, protected by the chemical stability of the monimolimnion.

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