Scientific drilling of Lake Chalco, Basin of Mexico (MexiDrill)
Scientific drilling of Lake Chalco, Basin of Mexico (MexiDrill)
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DOI：
10.5194/sd-26-1-2019
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发表时间：
2019-12-02
影响因子：
1.2
通讯作者：
Zeeden, Christian
中科院分区：
文献类型：
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作者：
Brown, Erik T.;Caballero, Margarita;Zeeden, Christian
墨西哥盆地钻探计划 MexiDrill 的主要科学目标是开发类似于 400 kyr 湖泊的连续高分辨率记录，记录北美热带环境变化。现场地点位于人口稠密、缺水的墨西哥城地区，这一记录具有特殊的社会意义。墨西哥中部的详细古气候重建将增强我们对北美热带地区长期自然气候变化及其与高纬度地区变化的关系的理解。该地点位于热带辐合带（ITCZ）的北缘，这里的现代降水量受到太平洋和大西洋盆地海面温度的影响。在末次盛冰期（LGM）期间，该地区冬季降水量增加，据推测是中纬度西风带向南移动的结果。因此，它代表了了解北美热带和亚热带大规模水文变化的关键空间节点，其海拔高度（2240 米）是北美西部大部分地区的典型海拔。此外，其沉积物还包含丰富的前全新世火山历史记录。了解该地区火山喷发的强度和频率关系将提高对未来活动进行风险评估的能力。爆炸性喷发沉积物还将用于提供充分利用古气候记录所需的强大年代学的支柱。我们在此报告 2016 年取芯活动的初步结果和外展活动。
The primary scientific objective of MexiDrill, the Basin of Mexico Drilling Program, is development of a continuous, high-resolution similar to 400 kyr lacustrine record of tropical North American environmental change. The field location, in the densely populated, water-stressed Mexico City region gives this record particular societal relevance. A detailed paleoclimate reconstruction from central Mexico will enhance our understanding of long-term natural climate variability in the North American tropics and its relationship with changes at higher latitudes. The site lies at the northern margin of the Intertropical Convergence Zone (ITCZ), where modern precipitation amounts are influenced by sea surface temperatures in the Pacific and Atlantic basins. During the Last Glacial Maximum (LGM), more winter precipitation at the site is hypothesized to have been a consequence of a southward displacement of the mid-latitude westerlies. It thus represents a key spatial node for understanding large-scale hydrological variability of tropical and subtropical North America and is at an altitude (2240 m a.s.l.), typical of much of western North America. In addition, its sediments contain a rich record of pre-Holocene volcanic history; knowledge of the magnitude and frequency relationships of the area's explosive volcanic eruptions will improve capacity for risk assessment of future activity. Explosive eruption deposits will also be used to provide the backbone of a robust chronology necessary for full exploitation of the paleoclimate record. Here we report initial results from, and outreach activities of, the 2016 coring campaign.