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1. |
Hot rocks and massive sulfide: Northern Juan de Fuca Ridge |
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Eos, Transactions American Geophysical Union,
Volume 73,
Issue 17,
1992,
Page 193-198
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摘要:
Leg 139 of the Ocean Drilling Program (ODP), completed on September 11, was the first part of a proposed two‐leg program to investigate hydrothermal processes and products at seafloor‐spreading centers covered with sediment. Sedimented spreading centers are unique and provide ideal targets for drilling; a regionally continuous, relatively impermeable sediment cover over zero‐age crust limits the recharge and discharge of hydrothermal fluids and thermally insulates the underlying crust. This creates a thermal regime in which high formation temperatures can occur at comparatively shallow levels in the crust. Where discharge of fluid does occur, very large hydrothermal sulfide deposits can be produced. The sediment may also preserve a relatively continuous stratigraphic record of magmatic, tectonic, and thermal events, providing clues to the spatial and temporal variability of these processes. The sediment also stabilizes the drill‐string and allows holes to be “spudded” without the operational expense of a complicated seafloo
ISSN:0002-8606
DOI:10.1029/91EO00157
年代:1992
数据来源: WILEY
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2. |
Antarctic science preserve polluted |
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Eos, Transactions American Geophysical Union,
Volume 73,
Issue 17,
1992,
Page 194-195
Lynn Teo Simarski,
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摘要:
Geophysicists are alarmed at the electromagnetic pollution of a research site in the Antarctic specifically set aside to study the ionosphere and magnetosphere. A private New Zealand communications company called Telecom recently constructed a satellite ground station within the boundaries of this Site of Special Scientific Interest (SSSI), protected since the mid‐1970s. The placement of a commercial facility within this site sets an ominous precedent not only for the sanctity of other SSSIs, but also for Specially Protected Areas—preserves not even open to scientific research, such as certain penguin rookeries.The roughly rectangular, one‐by‐one‐half mile site, located at Arrival Heights not far from McMurdo Station, is one of a number of areas protected under the Antarctic treaty for designated scientific activities. Many sites are set aside for geological or biological research, but this is the only one specifically for physica
ISSN:0002-8606
DOI:10.1029/91EO00159
年代:1992
数据来源: WILEY
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3. |
In Memoriam |
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Eos, Transactions American Geophysical Union,
Volume 73,
Issue 17,
1992,
Page 195-195
Anonymous,
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摘要:
Yukio Sugimura, an AGU member (Ocean Sciences) since 1963, died in November 1991 at age 59.Mae D. Silbergeld, an AGU member (Planetology) since 1972, died recently at age 69.
ISSN:0002-8606
DOI:10.1029/EO073i017p00195-02
年代:1992
数据来源: WILEY
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