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1. |
High‐resolution paleoclimate records from monsoon Asia |
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Eos, Transactions American Geophysical Union,
Volume 74,
Issue 51,
1993,
Page 601-604
Raymond S. Bradley,
David Sheu,
WeichyungWeichyung Wang,
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PDF (455KB)
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摘要:
Studying high‐resolution climate records of the past 2000 years has been identified as a high research priority by the IGBP PAGES program (International Geosphere‐Biosphere Program Past Global Changes) [Eddy, 1992] as well as by the U.S. Global Change research community [Bradley et al., 1991]. Monsoon Asia, particularly south and southeast Asia, has great potential for expanding our understanding of climatic fluctuations over the past 2 millennia. However, relatively little is known about climatic changes in that area over the last 2000 years. The lack of information is particularly significant because of the area's very large population and its vulnerability to climatic anomalies. At the same time, a real opportunity exists to document climatic changes in monsoon Asia by analyzing a number of types of high‐resolution paleoclimatic r
ISSN:0002-8606
DOI:10.1029/93EO00500
年代:1993
数据来源: WILEY
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2. |
Imaging Earth's upper mantle |
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Eos, Transactions American Geophysical Union,
Volume 74,
Issue 51,
1993,
Page 602-602
Peter M. Shearer,
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PDF (321KB)
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摘要:
New images of the three‐dimensional structure of Earth's upper mantle revealed by large‐scale processing of global seismic data are beginning to change our understanding of convection in the planet. The processing techniques combine data from hundreds of seismograms to distinguish weak features from the background noise. These procedures are termed “stacking” and are similar in many respects to reflection seismic techniques long used in the oil industry to image shallow crustal structure. However, the new results extend much deeper and map reflections from several internal discontinuities—interfaces separating different mantle layers—within the upper 700 km of the mantle. Observed deflections and topography on these discontinuities provide important constraints on the nature of the long‐term deformation of the mantle. The mantle is the 2900‐km‐thick shell surrounding Earth's core. It is solid but can slowly flow and overturn at the high pressures and temperatures present within
ISSN:0002-8606
DOI:10.1029/93EO00656
年代:1993
数据来源: WILEY
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