Methane hydrate at DSDP Site 84-570
Deep Sea Drilling Project (DSDP) studies at Site 570 on the landward slope of the Middle America Trench off Guatemala allow for the first time a quantitative estimate of the methane hydrate content in the massive mudstones deposited there. Drilling across the Guatemalan transect on DSDP Legs 67 and...
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1985
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.804449 2023-05-15T17:11:44+02:00 Methane hydrate at DSDP Site 84-570 Mathews, Mark A von Huene, Roland LATITUDE: 13.285300 * LONGITUDE: -91.392800 * DATE/TIME START: 1982-02-17T00:00:00 * DATE/TIME END: 1982-02-17T00:00:00 1985-12-18 application/zip, 4 datasets https://doi.pangaea.de/10.1594/PANGAEA.804449 https://doi.org/10.1594/PANGAEA.804449 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.804449 https://doi.org/10.1594/PANGAEA.804449 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Mathews, Mark A; von Huene, Roland (1985): Site 570 methane hydrate zone. In: von Heune, R; Aubouin, J; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office), 84, 773-790, https://doi.org/10.2973/dsdp.proc.84.134.1985 84-570_Site COMPCORE Composite Core Deep Sea Drilling Project DSDP Glomar Challenger Leg84 North Pacific/SLOPE Dataset 1985 ftpangaea https://doi.org/10.1594/PANGAEA.804449 https://doi.org/10.2973/dsdp.proc.84.134.1985 2023-01-20T07:32:50Z Deep Sea Drilling Project (DSDP) studies at Site 570 on the landward slope of the Middle America Trench off Guatemala allow for the first time a quantitative estimate of the methane hydrate content in the massive mudstones deposited there. Drilling across the Guatemalan transect on DSDP Legs 67 and 84 has resulted in the greatest number of visual observations of gas hydrate in any marine area. At Site 570, a 1.5-m-long section of massive methane hydrate was unexpectedly cored in an area where none of the usual signs of gas hydrate in seismic records were present. The sediment section is similar to that recovered at the other eight sites off Guatemala, but drilling at Site 570 may have penetrated through a fault zone that provided the space for accumulation of massive gas hydrate. The methane hydrate was analyzed using the following well logs: density, sonic, resistivity, gamma-ray, caliper, neutron porosity, and temperature. The density, sonic, and resistivity logs define a 15-m-thick hydrated zone within which a 4-m-thick nearly pure hydrate section is contained. The methane gas content ranges from 240 m**3 to 1400 m**3 per m**2 of lateral extent; and if the body extends a square kilometer, its total volume of stored gas could be from 240*10**6m**3 to 1400*10**6m**3. Because the acoustic impedance of hydrate calculated from the sonic and density logs shows no anomalous values, the shape and extent of the hydrate body cannot be defined in seismic records. Thus the body is theoretically nonreflective in contrast to the base of the hydrate reflection. The base of the gas hydrate reflection is presumed to be the result of the velocity contrast between sediment containing gas hydrate and sediment containing free gas. Dataset Methane hydrate PANGAEA - Data Publisher for Earth & Environmental Science Pacific ENVELOPE(-91.392800,-91.392800,13.285300,13.285300) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
84-570_Site COMPCORE Composite Core Deep Sea Drilling Project DSDP Glomar Challenger Leg84 North Pacific/SLOPE |
spellingShingle |
84-570_Site COMPCORE Composite Core Deep Sea Drilling Project DSDP Glomar Challenger Leg84 North Pacific/SLOPE Mathews, Mark A von Huene, Roland Methane hydrate at DSDP Site 84-570 |
topic_facet |
84-570_Site COMPCORE Composite Core Deep Sea Drilling Project DSDP Glomar Challenger Leg84 North Pacific/SLOPE |
description |
Deep Sea Drilling Project (DSDP) studies at Site 570 on the landward slope of the Middle America Trench off Guatemala allow for the first time a quantitative estimate of the methane hydrate content in the massive mudstones deposited there. Drilling across the Guatemalan transect on DSDP Legs 67 and 84 has resulted in the greatest number of visual observations of gas hydrate in any marine area. At Site 570, a 1.5-m-long section of massive methane hydrate was unexpectedly cored in an area where none of the usual signs of gas hydrate in seismic records were present. The sediment section is similar to that recovered at the other eight sites off Guatemala, but drilling at Site 570 may have penetrated through a fault zone that provided the space for accumulation of massive gas hydrate. The methane hydrate was analyzed using the following well logs: density, sonic, resistivity, gamma-ray, caliper, neutron porosity, and temperature. The density, sonic, and resistivity logs define a 15-m-thick hydrated zone within which a 4-m-thick nearly pure hydrate section is contained. The methane gas content ranges from 240 m**3 to 1400 m**3 per m**2 of lateral extent; and if the body extends a square kilometer, its total volume of stored gas could be from 240*10**6m**3 to 1400*10**6m**3. Because the acoustic impedance of hydrate calculated from the sonic and density logs shows no anomalous values, the shape and extent of the hydrate body cannot be defined in seismic records. Thus the body is theoretically nonreflective in contrast to the base of the hydrate reflection. The base of the gas hydrate reflection is presumed to be the result of the velocity contrast between sediment containing gas hydrate and sediment containing free gas. |
format |
Dataset |
author |
Mathews, Mark A von Huene, Roland |
author_facet |
Mathews, Mark A von Huene, Roland |
author_sort |
Mathews, Mark A |
title |
Methane hydrate at DSDP Site 84-570 |
title_short |
Methane hydrate at DSDP Site 84-570 |
title_full |
Methane hydrate at DSDP Site 84-570 |
title_fullStr |
Methane hydrate at DSDP Site 84-570 |
title_full_unstemmed |
Methane hydrate at DSDP Site 84-570 |
title_sort |
methane hydrate at dsdp site 84-570 |
publisher |
PANGAEA |
publishDate |
1985 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.804449 https://doi.org/10.1594/PANGAEA.804449 |
op_coverage |
LATITUDE: 13.285300 * LONGITUDE: -91.392800 * DATE/TIME START: 1982-02-17T00:00:00 * DATE/TIME END: 1982-02-17T00:00:00 |
long_lat |
ENVELOPE(-91.392800,-91.392800,13.285300,13.285300) |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
Supplement to: Mathews, Mark A; von Huene, Roland (1985): Site 570 methane hydrate zone. In: von Heune, R; Aubouin, J; et al. (eds.), Initial Reports of the Deep Sea Drilling Project, Washington (U.S. Govt. Printing Office), 84, 773-790, https://doi.org/10.2973/dsdp.proc.84.134.1985 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.804449 https://doi.org/10.1594/PANGAEA.804449 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.804449 https://doi.org/10.2973/dsdp.proc.84.134.1985 |
_version_ |
1766068505803751424 |