Fluid-volcano interaction in an active stratovolcano: the crater lake system of Poás volcano, Costa Rica

Gary L. Rowe, Susan Louise Brantley, Mario Fernandez, Jose F. Fernandez, Andrea Borgia, Jorge Barquero

Research output: Contribution to journalArticle

132 Citations (Scopus)

Abstract

Seismic and geochemical data collected at Poás volcano, Costa Rica, since 1978 suggest that temperature and chemical variations recorded in subaerial fumaroles and the crater lake are related to episodic release of heat and volatiles associated with hydrofracturing of the upper margin of the shallow magma body. Power outputs associated with these events approach 600 MW and are superimposed on a baseline energy flux of approximately 200 MW. The baseline heat flux suggests a magma solidification rate of 0.012 km3/yr and background volatile release rates of 1000 t/d H2O, 66 t/d, S, 13 t/d Cl, and 0.5 t/d F. These fluxes are comparable to fluxes of F, Cl and S exiting the magmatic/hydrothermal system through acidic flank springs and are about a factor of five less than estimated volatile fluxes through summit fumaroles during the high-temperature event of 1981-1983. Mass balance considerations suggest that heat released at the lake surface is primarily supplied by the ascent of heated brines supplemented by condensation of fumarolic steam. Calculated average seepage rates out of the lake (≈ 450 kg/s) indicate rapid convection of acidic lake brine through underlying lake sediments and pyroclastic deposits. Circulation of the extremely corrosive lake brine through the volcanoelastic material beneath the lake may enhance subsurface permeabilities. Fluxes of rock-forming elements observed in the Rio Agrio basin on the northwest flank of Poás suggest that dissolution and removal of volcano-elastic material occurs at a rate of approximately 1650 m3/yr. However, estimated sulfur fluxes from the cooling magma body suggest that porosity created by this dissolution could quickly be filled by the deposition of native sulfur. Finally,analysis of heat and water budgets for the crater lake over the period 1978-1989 indicates that the recent decline and disappearance of the lake was caused by variations in summit rainfall combined with an increase in subsurface heat flow to the lake in 1987-1988. The increase in heat flow is related to continued degassing of high-temperature volatiles following a hydrofracturing/magma ascent episode that occurred in 1986.

Original languageEnglish (US)
Pages (from-to)23-51
Number of pages29
JournalJournal of Volcanology and Geothermal Research
Volume49
Issue number1-2
DOIs
StatePublished - Jan 1 1992

Fingerprint

Costa Rica
crater lake
stratovolcano
Volcanoes
lakes
craters
volcanoes
Lakes
volcano
Fluids
fluid
fluids
lake
magma
Fluxes
interactions
fumarole
heat flow
brine
ascent

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geochemistry and Petrology

Cite this

Rowe, Gary L. ; Brantley, Susan Louise ; Fernandez, Mario ; Fernandez, Jose F. ; Borgia, Andrea ; Barquero, Jorge. / Fluid-volcano interaction in an active stratovolcano : the crater lake system of Poás volcano, Costa Rica. In: Journal of Volcanology and Geothermal Research. 1992 ; Vol. 49, No. 1-2. pp. 23-51.
@article{77e87862d6154373bfdca97000254237,
title = "Fluid-volcano interaction in an active stratovolcano: the crater lake system of Po{\'a}s volcano, Costa Rica",
abstract = "Seismic and geochemical data collected at Po{\'a}s volcano, Costa Rica, since 1978 suggest that temperature and chemical variations recorded in subaerial fumaroles and the crater lake are related to episodic release of heat and volatiles associated with hydrofracturing of the upper margin of the shallow magma body. Power outputs associated with these events approach 600 MW and are superimposed on a baseline energy flux of approximately 200 MW. The baseline heat flux suggests a magma solidification rate of 0.012 km3/yr and background volatile release rates of 1000 t/d H2O, 66 t/d, S, 13 t/d Cl, and 0.5 t/d F. These fluxes are comparable to fluxes of F, Cl and S exiting the magmatic/hydrothermal system through acidic flank springs and are about a factor of five less than estimated volatile fluxes through summit fumaroles during the high-temperature event of 1981-1983. Mass balance considerations suggest that heat released at the lake surface is primarily supplied by the ascent of heated brines supplemented by condensation of fumarolic steam. Calculated average seepage rates out of the lake (≈ 450 kg/s) indicate rapid convection of acidic lake brine through underlying lake sediments and pyroclastic deposits. Circulation of the extremely corrosive lake brine through the volcanoelastic material beneath the lake may enhance subsurface permeabilities. Fluxes of rock-forming elements observed in the Rio Agrio basin on the northwest flank of Po{\'a}s suggest that dissolution and removal of volcano-elastic material occurs at a rate of approximately 1650 m3/yr. However, estimated sulfur fluxes from the cooling magma body suggest that porosity created by this dissolution could quickly be filled by the deposition of native sulfur. Finally,analysis of heat and water budgets for the crater lake over the period 1978-1989 indicates that the recent decline and disappearance of the lake was caused by variations in summit rainfall combined with an increase in subsurface heat flow to the lake in 1987-1988. The increase in heat flow is related to continued degassing of high-temperature volatiles following a hydrofracturing/magma ascent episode that occurred in 1986.",
author = "Rowe, {Gary L.} and Brantley, {Susan Louise} and Mario Fernandez and Fernandez, {Jose F.} and Andrea Borgia and Jorge Barquero",
year = "1992",
month = "1",
day = "1",
doi = "10.1016/0377-0273(92)90003-V",
language = "English (US)",
volume = "49",
pages = "23--51",
journal = "Journal of Volcanology and Geothermal Research",
issn = "0377-0273",
publisher = "Elsevier",
number = "1-2",

}

Fluid-volcano interaction in an active stratovolcano : the crater lake system of Poás volcano, Costa Rica. / Rowe, Gary L.; Brantley, Susan Louise; Fernandez, Mario; Fernandez, Jose F.; Borgia, Andrea; Barquero, Jorge.

In: Journal of Volcanology and Geothermal Research, Vol. 49, No. 1-2, 01.01.1992, p. 23-51.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fluid-volcano interaction in an active stratovolcano

T2 - the crater lake system of Poás volcano, Costa Rica

AU - Rowe, Gary L.

AU - Brantley, Susan Louise

AU - Fernandez, Mario

AU - Fernandez, Jose F.

AU - Borgia, Andrea

AU - Barquero, Jorge

PY - 1992/1/1

Y1 - 1992/1/1

N2 - Seismic and geochemical data collected at Poás volcano, Costa Rica, since 1978 suggest that temperature and chemical variations recorded in subaerial fumaroles and the crater lake are related to episodic release of heat and volatiles associated with hydrofracturing of the upper margin of the shallow magma body. Power outputs associated with these events approach 600 MW and are superimposed on a baseline energy flux of approximately 200 MW. The baseline heat flux suggests a magma solidification rate of 0.012 km3/yr and background volatile release rates of 1000 t/d H2O, 66 t/d, S, 13 t/d Cl, and 0.5 t/d F. These fluxes are comparable to fluxes of F, Cl and S exiting the magmatic/hydrothermal system through acidic flank springs and are about a factor of five less than estimated volatile fluxes through summit fumaroles during the high-temperature event of 1981-1983. Mass balance considerations suggest that heat released at the lake surface is primarily supplied by the ascent of heated brines supplemented by condensation of fumarolic steam. Calculated average seepage rates out of the lake (≈ 450 kg/s) indicate rapid convection of acidic lake brine through underlying lake sediments and pyroclastic deposits. Circulation of the extremely corrosive lake brine through the volcanoelastic material beneath the lake may enhance subsurface permeabilities. Fluxes of rock-forming elements observed in the Rio Agrio basin on the northwest flank of Poás suggest that dissolution and removal of volcano-elastic material occurs at a rate of approximately 1650 m3/yr. However, estimated sulfur fluxes from the cooling magma body suggest that porosity created by this dissolution could quickly be filled by the deposition of native sulfur. Finally,analysis of heat and water budgets for the crater lake over the period 1978-1989 indicates that the recent decline and disappearance of the lake was caused by variations in summit rainfall combined with an increase in subsurface heat flow to the lake in 1987-1988. The increase in heat flow is related to continued degassing of high-temperature volatiles following a hydrofracturing/magma ascent episode that occurred in 1986.

AB - Seismic and geochemical data collected at Poás volcano, Costa Rica, since 1978 suggest that temperature and chemical variations recorded in subaerial fumaroles and the crater lake are related to episodic release of heat and volatiles associated with hydrofracturing of the upper margin of the shallow magma body. Power outputs associated with these events approach 600 MW and are superimposed on a baseline energy flux of approximately 200 MW. The baseline heat flux suggests a magma solidification rate of 0.012 km3/yr and background volatile release rates of 1000 t/d H2O, 66 t/d, S, 13 t/d Cl, and 0.5 t/d F. These fluxes are comparable to fluxes of F, Cl and S exiting the magmatic/hydrothermal system through acidic flank springs and are about a factor of five less than estimated volatile fluxes through summit fumaroles during the high-temperature event of 1981-1983. Mass balance considerations suggest that heat released at the lake surface is primarily supplied by the ascent of heated brines supplemented by condensation of fumarolic steam. Calculated average seepage rates out of the lake (≈ 450 kg/s) indicate rapid convection of acidic lake brine through underlying lake sediments and pyroclastic deposits. Circulation of the extremely corrosive lake brine through the volcanoelastic material beneath the lake may enhance subsurface permeabilities. Fluxes of rock-forming elements observed in the Rio Agrio basin on the northwest flank of Poás suggest that dissolution and removal of volcano-elastic material occurs at a rate of approximately 1650 m3/yr. However, estimated sulfur fluxes from the cooling magma body suggest that porosity created by this dissolution could quickly be filled by the deposition of native sulfur. Finally,analysis of heat and water budgets for the crater lake over the period 1978-1989 indicates that the recent decline and disappearance of the lake was caused by variations in summit rainfall combined with an increase in subsurface heat flow to the lake in 1987-1988. The increase in heat flow is related to continued degassing of high-temperature volatiles following a hydrofracturing/magma ascent episode that occurred in 1986.

UR - http://www.scopus.com/inward/record.url?scp=0026448487&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026448487&partnerID=8YFLogxK

U2 - 10.1016/0377-0273(92)90003-V

DO - 10.1016/0377-0273(92)90003-V

M3 - Article

AN - SCOPUS:0026448487

VL - 49

SP - 23

EP - 51

JO - Journal of Volcanology and Geothermal Research

JF - Journal of Volcanology and Geothermal Research

SN - 0377-0273

IS - 1-2

ER -