نتایج جستجو برای: holocene

تعداد نتایج: 8437  

2016
J. K. Park L. G. Thompson C. F. Boutron C. P. Ferrari

Nine sections from the Sajama ice core recovered from the summit of an extinct Andean volcano in Bolivia were analysed for various heavy metals to assess anthropogenic changes in the tropical upper troposphere over South America. These sam ples include two sections dating from 14, 100 to 19,200 years BP, corresponding to the Last Glacial Stage (LOS), one section dating from 2800 years BP (the l...

2008
Juan He Meixun Zhao Li Li Hui Wang Pinxian Wang

High-resolution molecular abundance records for several marine biomarkers during the last glacial and Holocene have been generated for core MD05-2904 (19 27.32’N, 116 15.15’E, 2066 m water depth) from the northern South China Sea. The U 37 SST record indicates a 4.4 C cooling during the Last Glacial Maximum for this site, consistent with previous reconstructions. The contents of C37 alkenones, ...

2018
Paulo Ruiz Sara Mana Amalia Gutiérrez Gerardo Alarcón José Garro Gerardo J. Soto

Citation: Ruiz P, Mana S, Gutiérrez A, Alarcón G, Garro J and Soto GJ (2018) Geomorphological Insights on Human-Volcano Interactions and Use of Volcanic Materials in Pre-Hispanic Cultures of Costa Rica through the Holocene. Front. Earth Sci. 6:13. doi: 10.3389/feart.2018.00013 Geomorphological Insights on Human-Volcano Interactions and Use of Volcanic Materials in Pre-Hispanic Cultures of Costa...

2002
FIDEL COSTA BRAD SINGER

Volcán San Pedro in the Andean Southern Volcanic Zone (SVZ) Consequently, the role of young, unradiogenic hydrous gabbro in Chile, comprises Holocene basaltic to dacitic lavas with trace generating dacite and contaminating basalt may be underappreciated element and strontium isotope ratios more variable than those of in the SVZ. most Pleistocene lavas of the underlying Tatara–San Pedro complex....

2008
Cheng-Bang An Fa-Hu Chen Loukas Barton

Article history: Holocene environmental ch Received 1 September 2005

2013
Nicholas L Balascio William J D'Andrea Raymond S Bradley Bianca B Perren

Holocene paleoclimate records from Greenland help us understand the response of the Greenland Ice Sheet and regional oceanic and atmospheric circulation systems to natural climate variability in order to place recent changes in a longer-term perspective. Here biogeochemical analysis of a lake sediment core from southeast Greenland is used to define changes in moisture balance and runoff during ...

2018
T E Arnold W F Kenney J H Curtis T S Bianchi M Brenner

We carried out geochemical analyses on a sediment core from Lake Harris, Florida (USA) to identify sources of organic matter to the sediment throughout the Holocene, and relate changes in those sources to shifts in past climate and environmental conditions. We hypothesized that the sources of organic matter changed in response to regional hydrologic shifts following de-glaciation, and to human ...

2013
Nathan D. Stansell Donald T. Rodbell Mark B. Abbott Bryan G. Mark

Sediment records from proglacial lakes between 9 and 10 S in the western Cordillera of the Peruvian Andes document the waxing and waning of alpine glaciers since the end of the Lateglacial stage. These records from the southern tropical Andes provide supporting evidence that the early Holocene (between 12 and 8 ka) was relatively warm and dry, and the middle Holocene (between 8 and 4 ka) was ma...

2010
Yochanan Kushnir Mordechai Stein

The importance of understanding processes that govern the hydroclimate of the Mediterranean Basin is highlighted by the projected significant drying of the region in response to the increase in greenhouse gas concentrations. Here we study the long-term hydroclimatic variability of the central Levant region, situated in the eastern boundary of the Basin, as reveled by instrumental observations a...

1997
Zicheng Yu John H. McAndrews Ueli Eicher

Paleoclimatic studies with multiple proxy data have increasingly improved our understanding of Holocene climate. A dry and warm climate in the early and middle Holocene has been documented by numerous studies in eastern North America (T. Webb et al., 1983, 1993; COHMAP Members, 1988; Baker et al., 1992; R. Webb et al., 1993). Recent studies show that the classic dry and warm prairie period in m...

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