A first estimation of gas hydrates offshore Patagonia (Chile)

Lucía Villar-Muñoz, Joaquim P. Bento, Dirk Klaeschen, Umberta Tinivella, Iván de la Cruz Vargas-Cordero, Jan H. Behrmann

Resultado de la investigación: Article

5 Citas (Scopus)

Resumen

In many places along the central and southern Chilean active continental margin sedimentary successions covering the forearc contain methane hydrate, resulting from a mixture of biogenic and thermogenic processes. Here, we report the spatial distribution of gas hydrate in the accretionary prism and forearc sediments offshore western Patagonia (50°S and 57°S), landward of the Antarctica-South America plate boundary. Knowledge of the forearc structure here is limited, owing to the small number of reflection seismic profiles available, lack of high-resolution bathymetry data and the absence of scientific drillholes. However bottom-simulating reflectors (BSR) indicative of gas hydrate occur regionally extensive below about one third of the forearc slope, between about 280 and 630 m below sea floor. BSR-derived heat flow was calculated at about 30 and 70 mWm−2. These are typical values above subduction zones of oceanic crust older than 10 Ma, where vigorous fluid flow above young and hot subducting oceanic crust has leveled off. To move towards an estimate of gas hydrate present in the sediments, the velocity model was converted into a gas-phase concentration model using data from one of the seismic sections. Average thickness of gas hydrate is about 290 m, and average concentrations estimated are in a range of 3.4%–10%. If we use the minimum value of 3.4%, the amount of methane present in the region is about 3.0 × 1013 m3 at standard pressure-temperature conditions. We conclude that the Pacific forearc of Patagonia area is an important reservoir of methane hydrates and we propose this area be considered as a potential methane hydrate concentrated zone and a key area to be investigated in the future.

Idioma originalEnglish
Páginas (desde-hasta)232-239
Número de páginas8
PublicaciónMarine and Petroleum Geology
Volumen96
DOI
EstadoPublished - 1 sep 2018

Huella dactilar

Chile
gas hydrate
hydrates
methane
gases
oceanic crust
accretionary prism
reflectors
plate boundary
bathymetry
crusts
heat flow
sediments
sediment
seismic reflection
subduction zone
fluid flow
continental margin
seafloor
spatial distribution

ASJC Scopus subject areas

  • Oceanography
  • Geophysics
  • Geology
  • Economic Geology
  • Stratigraphy

Citar esto

Villar-Muñoz, Lucía ; Bento, Joaquim P. ; Klaeschen, Dirk ; Tinivella, Umberta ; Vargas-Cordero, Iván de la Cruz ; Behrmann, Jan H. / A first estimation of gas hydrates offshore Patagonia (Chile). En: Marine and Petroleum Geology. 2018 ; Vol. 96. pp. 232-239.
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title = "A first estimation of gas hydrates offshore Patagonia (Chile)",
abstract = "In many places along the central and southern Chilean active continental margin sedimentary successions covering the forearc contain methane hydrate, resulting from a mixture of biogenic and thermogenic processes. Here, we report the spatial distribution of gas hydrate in the accretionary prism and forearc sediments offshore western Patagonia (50°S and 57°S), landward of the Antarctica-South America plate boundary. Knowledge of the forearc structure here is limited, owing to the small number of reflection seismic profiles available, lack of high-resolution bathymetry data and the absence of scientific drillholes. However bottom-simulating reflectors (BSR) indicative of gas hydrate occur regionally extensive below about one third of the forearc slope, between about 280 and 630 m below sea floor. BSR-derived heat flow was calculated at about 30 and 70 mWm−2. These are typical values above subduction zones of oceanic crust older than 10 Ma, where vigorous fluid flow above young and hot subducting oceanic crust has leveled off. To move towards an estimate of gas hydrate present in the sediments, the velocity model was converted into a gas-phase concentration model using data from one of the seismic sections. Average thickness of gas hydrate is about 290 m, and average concentrations estimated are in a range of 3.4{\%}–10{\%}. If we use the minimum value of 3.4{\%}, the amount of methane present in the region is about 3.0 × 1013 m3 at standard pressure-temperature conditions. We conclude that the Pacific forearc of Patagonia area is an important reservoir of methane hydrates and we propose this area be considered as a potential methane hydrate concentrated zone and a key area to be investigated in the future.",
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A first estimation of gas hydrates offshore Patagonia (Chile). / Villar-Muñoz, Lucía; Bento, Joaquim P.; Klaeschen, Dirk; Tinivella, Umberta; Vargas-Cordero, Iván de la Cruz; Behrmann, Jan H.

En: Marine and Petroleum Geology, Vol. 96, 01.09.2018, p. 232-239.

Resultado de la investigación: Article

TY - JOUR

T1 - A first estimation of gas hydrates offshore Patagonia (Chile)

AU - Villar-Muñoz, Lucía

AU - Bento, Joaquim P.

AU - Klaeschen, Dirk

AU - Tinivella, Umberta

AU - Vargas-Cordero, Iván de la Cruz

AU - Behrmann, Jan H.

PY - 2018/9/1

Y1 - 2018/9/1

N2 - In many places along the central and southern Chilean active continental margin sedimentary successions covering the forearc contain methane hydrate, resulting from a mixture of biogenic and thermogenic processes. Here, we report the spatial distribution of gas hydrate in the accretionary prism and forearc sediments offshore western Patagonia (50°S and 57°S), landward of the Antarctica-South America plate boundary. Knowledge of the forearc structure here is limited, owing to the small number of reflection seismic profiles available, lack of high-resolution bathymetry data and the absence of scientific drillholes. However bottom-simulating reflectors (BSR) indicative of gas hydrate occur regionally extensive below about one third of the forearc slope, between about 280 and 630 m below sea floor. BSR-derived heat flow was calculated at about 30 and 70 mWm−2. These are typical values above subduction zones of oceanic crust older than 10 Ma, where vigorous fluid flow above young and hot subducting oceanic crust has leveled off. To move towards an estimate of gas hydrate present in the sediments, the velocity model was converted into a gas-phase concentration model using data from one of the seismic sections. Average thickness of gas hydrate is about 290 m, and average concentrations estimated are in a range of 3.4%–10%. If we use the minimum value of 3.4%, the amount of methane present in the region is about 3.0 × 1013 m3 at standard pressure-temperature conditions. We conclude that the Pacific forearc of Patagonia area is an important reservoir of methane hydrates and we propose this area be considered as a potential methane hydrate concentrated zone and a key area to be investigated in the future.

AB - In many places along the central and southern Chilean active continental margin sedimentary successions covering the forearc contain methane hydrate, resulting from a mixture of biogenic and thermogenic processes. Here, we report the spatial distribution of gas hydrate in the accretionary prism and forearc sediments offshore western Patagonia (50°S and 57°S), landward of the Antarctica-South America plate boundary. Knowledge of the forearc structure here is limited, owing to the small number of reflection seismic profiles available, lack of high-resolution bathymetry data and the absence of scientific drillholes. However bottom-simulating reflectors (BSR) indicative of gas hydrate occur regionally extensive below about one third of the forearc slope, between about 280 and 630 m below sea floor. BSR-derived heat flow was calculated at about 30 and 70 mWm−2. These are typical values above subduction zones of oceanic crust older than 10 Ma, where vigorous fluid flow above young and hot subducting oceanic crust has leveled off. To move towards an estimate of gas hydrate present in the sediments, the velocity model was converted into a gas-phase concentration model using data from one of the seismic sections. Average thickness of gas hydrate is about 290 m, and average concentrations estimated are in a range of 3.4%–10%. If we use the minimum value of 3.4%, the amount of methane present in the region is about 3.0 × 1013 m3 at standard pressure-temperature conditions. We conclude that the Pacific forearc of Patagonia area is an important reservoir of methane hydrates and we propose this area be considered as a potential methane hydrate concentrated zone and a key area to be investigated in the future.

KW - BSR

KW - Chile

KW - Forearc

KW - Gas hydrate

KW - Heat flow

KW - Patagonia

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U2 - 10.1016/j.marpetgeo.2018.06.002

DO - 10.1016/j.marpetgeo.2018.06.002

M3 - Article

VL - 96

SP - 232

EP - 239

JO - Marine and Petroleum Geology

JF - Marine and Petroleum Geology

SN - 0264-8172

ER -