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 ◽  
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 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.

scholarly journals Parallel and non-parallel changes of the gut microbiota during trophic diversification in repeated young adaptive radiations of sympatric cichlid fish

2019 ◽  
Author(s):  
Andreas Härer ◽  
Julián Torres-Dowdall ◽  
Sina Rometsch ◽  
Elizabeth Yohannes ◽  
Gonzalo Machado-Schiaffino ◽  
...  
Keyword(s):  
Gut Microbiota ◽  
Trophic Ecology ◽  
Crater Lake ◽  
Parallel Evolution ◽  
Cichlid Fish ◽  
Crater Lakes ◽  
Functional Changes ◽  
Ecological Diversification ◽  
Early Stages ◽  
Adaptive Radiations

AbstractRecent increases in understanding the ecological and evolutionary roles of microbial communities has underscored their importance for their hosts’ biology. Yet, little is known about gut microbiota dynamics during early stages of ecological diversification and speciation. We studied the gut microbiota of extremely young adaptive radiations of Nicaraguan crater lake cichlid fish (Amphilophus cf. citrinellus) to test the hypothesis that parallel evolution in trophic ecology is associated with parallel changes of the gut microbiota. Bacterial communities of the water (eDNA) and guts were highly distinct, indicating that the gut microbiota is shaped by host-specific factors. Across individuals of the same crater lake, differentiation in trophic ecology was associated with gut microbiota differentiation, suggesting that diet affects the gut microbiota. However, differences in trophic ecology were much more pronounced across than within species whereas little evidence was found for similar patterns in taxonomic and functional changes of the gut microbiota. Across the two crater lakes, we could not detect evidence for parallel changes of the gut microbiota associated with trophic ecology. Similar cases of non-parallelism have been observed in other recently diverged fish species and might be explained by a lack of clearly differentiated niches during early stages of ecological diversification.

scholarly journals Selected Crater and Small Caldera Lakes in Alaska: Characteristics and Hazards

2022 ◽  
Vol 9 ◽  
Author(s):  
Christopher F. Waythomas
Keyword(s):  
Crater Lake ◽  
Summit Crater ◽  
Dam Break ◽  
Pyroclastic Deposits ◽  
Crater Lakes ◽  
Water Volumes ◽  
Lake Drainage ◽  
External Water ◽  
Volcaniclastic Deposits

This study addresses the characteristics, potential hazards, and both eruptive and non-eruptive role of water at selected volcanic crater lakes in Alaska. Crater lakes are an important feature of some stratovolcanoes in Alaska. Of the volcanoes in the state with known Holocene eruptive activity, about one third have summit crater lakes. Also included are two volcanoes with small caldera lakes (Katmai, Kaguyak). The lakes play an important but not well studied role in influencing eruptive behavior and pose some significant hydrologic hazards. Floods from crater lakes in Alaska are evaluated by estimating maximum potential crater lake water volumes and peak outflow discharge with a dam-break model. Some recent eruptions and hydrologic events that involved crater lakes also are reviewed. The large volumes of water potentially hosted by crater lakes in Alaska indicate that significant flowage hazards resulting from catastrophic breaching of crater rims are possible. Estimates of maximum peak flood discharge associated with breaching of lake-filled craters derived from dam-break modeling indicate that flood magnitudes could be as large as 103–106 m3/s if summit crater lakes drain rapidly when at maximum volume. Many of the Alaska crater lakes discussed are situated in hydrothermally altered craters characterized by complex assemblages of stratified unconsolidated volcaniclastic deposits, in a region known for large magnitude (>M7) earthquakes. Although there are only a few historical examples of eruptions involving crater lakes in Alaska, these provide noteworthy examples of the role of external water in cooling pyroclastic deposits, acidic crater-lake drainage, and water-related hazards such as lahars and base surge.

scholarly journals Local variation and parallel evolution: morphological and genetic diversity across a species complex of neotropical crater lake cichlid fishes

2010 ◽  
Vol 365 (1547) ◽  
pp. 1763-1782 ◽  
Author(s):  
Kathryn R. Elmer ◽  
Henrik Kusche ◽  
Topi K. Lehtonen ◽  
Axel Meyer
Keyword(s):  
Genetic Diversity ◽  
Species Complex ◽  
Body Shape ◽  
Crater Lake ◽  
Shape Change ◽  
Parallel Evolution ◽  
Cichlid Fish ◽  
Shape Variation ◽  
Body Depth ◽  
Crater Lakes

The polychromatic and trophically polymorphic Midas cichlid fish species complex ( Amphilophus cf. citrinellus ) is an excellent model system for studying the mechanisms of speciation and patterns of phenotypic diversification in allopatry and in sympatry. Here, we first review research to date on the species complex and the geological history of its habitat. We analyse body shape variation from all currently described species in the complex, sampled from six crater lakes (maximally 1.2–23.9 kyr old) and both great lakes in Nicaragua. We find that Midas cichlid populations in each lake have their own characteristic body shape. In lakes with multiple sympatric species of Midas cichlid, each species has a distinct body shape. Across the species complex, most body shape change relates to body depth, head, snout and mouth shape and caudal peduncle length. There is independent parallel evolution of an elongate limnetic species in at least two crater lakes. Mitochondrial genetic diversity is higher in crater lakes with multiple species. Midas cichlid species richness increases with the size and age of the crater lakes, though no such relationship exists for the other syntopic fishes. We suggest that crater lake Midas cichlids follow the predicted pattern of an adaptive radiation, with early divergence of each crater lake colonization, followed by intralacustrine diversification and speciation by ecological adaptation and sexual selection.

scholarly journals Experimental Study on the Self-Healing Behavior of Fractured Rocks Induced by Water-CO2-Rock Interactions in the Shendong Coalfield

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jinfeng Ju ◽  
Quansheng Li ◽  
Jialin Xu
Keyword(s):  
Clay Minerals ◽  
Water Permeability ◽  
Fractured Rocks ◽  
The Self ◽  
Coarse Grained ◽  
Ionic Exchange ◽  
Self Healing ◽  
Rock Interaction ◽  
Fine Grained ◽  
Initial Stage

This study experimentally investigated the self-healing behavior, referring to the naturally occurring water permeability decrease, of fractured rocks exposed to water-CO2-rock interaction (WCRI). The experiment was conducted on prefractured specimens of three rock types typical of the Shendong coalfield: coarse-grained sandrock, fine-grained sandrock, and sandy mudrock. During the experiment, which ran for nearly 15 months, all three specimens exhibited decreasing permeabilities. The coarse- and fine-grained sandrock specimens exhibited smooth decreases in permeability, with approximately parallel permeability time curves, whereas that of the sandy mudrock specimen decreased rapidly during the initial stage and slowly during later stages. The sandrock specimens were rich in feldspars, which were dissolved and/or corroded and involved in ionic exchange reactions with CO2 and groundwater, thereby generating secondary minerals (such as kaolinite, quartz, and sericite) or CaSO4 sediments. These derivative matters adhered to the fracture surface, thereby gradually repairing fractures and decreasing the water permeability of the fractured rocks. In comparison, the sandy mudrock had a high content of clay minerals, and the water-rock interaction caused rapid expansions of illite, mixed illite-smectite, and other clay minerals, thereby narrowing the fractures and causing the rapid permeability decrease during the initial stage. In later stages, the derivative matters generated by the dissolution and/or corrosion of feldspars and other aluminum silicate minerals in the mudrock filled and sealed the fractures, causing the slow permeability decreases during the later stages, as in the sandrock specimens. Neutral and basic groundwater conditions facilitated better self-healing of fractured mudrocks rich in clay minerals, whereas acidic groundwater conditions and the presence of CO2 facilitated better self-healing of fractured sandrocks. Thus, this study’s results are of significant value to aquifer restoration efforts in the Shendong coalfield and other ecologically vulnerable mining areas.

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 Characteristics of the summit lakes of Ambae volcano and their potential for generating lahars

2009 ◽  
Vol 9 (4) ◽  
pp. 1471-1478 ◽  
Author(s):  
P. Bani ◽  
J.-L. Join ◽  
S. J. Cronin ◽  
M. Lardy ◽  
I. Rouet ◽  
...  
Keyword(s):  
Crater Lake ◽  
Volcanic Eruptions ◽  
Current Level ◽  
Water Volume ◽  
Central Position ◽  
Caldera Wall ◽  
Loss Of Life ◽  
Crater Lakes ◽  
Outburst Floods ◽  
Summit Caldera

Abstract. Volcanic eruptions through crater lakes often generate lahars, causing loss of life and property. On Ambae volcano, recent eruptive activities have rather tended to reduce the water volume in the crater lake (Lake Voui), in turn, reducing the chances for outburst floods. Lake Voui occupies a central position in the summit caldera and is well enclosed by the caldera relief. Eruptions with significantly higher magnitude than that of 1995 and 2005 are required for an outburst. A more probable scenario for lahar events is the overflow from Lake Manaro Lakua bounded on the eastern side by the caldera wall. Morphology and bathymetry analysis have been used to identify the weakest point of the caldera rim from which water from Lake Manaro Lakua may overflow to initiate lahars. The 1916 disaster described on south-east Ambae was possibly triggered by such an outburst from Lake Manaro Lakua. Taking into account the current level of Lake Manaro Lakua well below a critical overflow point, and the apparently low potential of Lake Voui eruptions to trigger lahars, the Ambae summit lakes may not be directly responsible for numerous lahar deposits identified around the Island.

scholarly journals Reconstruction of the primary bottom of a unique crater lake in the “Meteoryt Morasko Reserve” (Poland)

2019 ◽  
Vol 17 (1) ◽  
pp. 5-16
Author(s):  
Adam Choiński ◽  
Andrzej Muszyński ◽  
Mariusz Ptak ◽  
Marcin Słowik
Keyword(s):  
Organic Matter ◽  
Water Level ◽  
Crater Lake ◽  
Lake Basin ◽  
Crater Lakes ◽  
Scientific Disciplines ◽  
The World ◽  
Research Procedure ◽  
The Subject ◽  
Widespread Interest

Abstract There are a total of several million lakes in the world, which includes only approximately 30 crater lakes. Due to this extreme global rarity, they are the subject of research in many scientific disciplines. In spite of the widespread interest in them, however, many issues still require detailed investigation. In the case of the Morasko crater lake (Poland), hydrological research has been weakly developed so far. The undertaken analysis, which employed a complex research procedure involving the use of georadar, geological corings and bathymetric measurements, aimed to determine the primary bottom of the lake, and further to determine the scale and rate of its evolution. The modern water level suggests that the lake basin is currently approximately 55% filled in with organic matter, and the rate of its sedimentation in the deepest place can be estimated at approximately 0.8 mm·y−1.

scholarly journals Rare Earth Elements Variations in a Hyperacid Crater Lake and Their Relations With Changes in Phreatic Activity, Physico-Chemical Parameters, and Chemical Composition: The Case of Poás Volcano (Costa Rica)

2022 ◽  
Vol 9 ◽  
Author(s):  
Sabrina Pappaterra ◽  
Claudio Inguaggiato ◽  
Dmitri Rouwet ◽  
Raúl Mora-Amador ◽  
Carlos Ramírez-Umaña ◽  
...  
Keyword(s):  
Rare Earth ◽  
Costa Rica ◽  
Rare Earth Elements ◽  
Lake Water ◽  
Crater Lake ◽  
Major Elements ◽  
Chemical Parameters ◽  
Crater Lakes ◽  
Physico Chemical ◽  
Poas Volcano

Decades of geochemical monitoring at active crater lakes worldwide have confirmed that variations in major elements and physico-chemical parameters are useful to detect changes in volcanic activity. However, it is still arduous to identify precursors of single phreatic eruptions. During the unrest phase of 2009–2016, at least 679 phreatic eruptions occurred at the hyperacid and hypersaline crater lake Laguna Caliente of Poás volcano (Costa Rica). In this study, we investigate the temporal variations of Rare Earth Elements (REE) dissolved in Laguna Caliente in order to 1) scrutinize if they can be used as a new geochemical tool to monitor changes of phreatic activity at hyperacid crater lakes and 2) identify the geochemical processes responsible for the variations of REE concentrations in the lake. The total concentration of REE varies from 950 to 2,773 μg kg−1. (La/Pr)N-local rock ratios range from 0.93 to 1.35, and Light REE over Heavy REE (LREE/HREE)N-local rock ratios vary from 0.71 to 0.95. These same parameters vary in relation to significant changes in phreatic activity; in particular, the (La/Pr)N-local rock ratio increases as phreatic activity increases, while that of (LREE/HREE)N-local rock decreases when phreatic activity increases. REE concentrations and their ratios were compared with the variations of major elements and physico-chemical parameters of the lake. Calcium versus (La/Pr)N-local rock and versus (LREE/HREE)N-local rock ratios show different trends compared to the other major elements (Na, K, Mg, Al, Fe, SO4, and Cl). Moreover, a higher loss of Ca (up to 2,835 ppm) in lake water was found with respect to the loss of Al, K, and Na. This loss of Ca is argued to be due to gypsum precipitation, a process corroborated by the mass balance calculation simulating the precipitation of gypsum and the contemporaneous removal of REE from the lake water. The observed relations between REE, changes in phreatic activity, and the parameters commonly used for the monitoring of hyperacid volcanic lakes encourage investigating more on the temporal and cause-effect relationship between REE dynamics and changes in phreatic activity at crater lake-bearing volcanoes.

Sign in / Sign up

Export Citation Format

Share Document