ニュージーランド海氷期:ミレニアムスケールで南部の気候が3.9万年前に変化した
1School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia. bob.carter@jcu.edu.au
まとめ
海洋掘削プログラムサイト1119
科学分野:
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
- 海洋地質学 海洋地質学
- 氷河研究 氷河研究
背景:
- 海洋掘削プログラムサイト1119は,ニュージーランド南アルプスの氷河からの堆積物を捕獲します.
- この堆積物は,3900万年前に遡る長期的な気候記録を提供する.
- 場所の位置は,南半球の気候動態についての洞察を提供します.
研究 の 目的:
- 堆積物コアのデータを用いて,古気候の歴史を再構築する.
- ニュージーランドの氷河記録と南極の気候記録を相関させるため.
- 大気,海洋,氷河の気候の歴史との関係を調査する.
主な方法:
- 堆積物核からの天然のガンマ線信号の分析.
- 堆積物コアのデータと南極の氷のコアの記録 (Vostok) の比較.
- 海洋気候再構築のための酸素同位体時間系列との相関.
主要な成果:
- 堆積物の中核は,3,900万年前から南島氷冠の歴史を明らかにしています.
- 最近の気候記録 (0.37万年前まで) は,南極の気候史と一致しています.
- 古い記録は,中緯度と南極の気温の代理として機能します.
- ガンマ線信号はまた,海洋気候の歴史を反映しています.
結論:
- 海洋掘削プログラムサイト1119からの堆積物核は,南半球の古気候の貴重なプロキシを提供します.
- この研究は,氷河,大気,海洋の気候の歴史を何百万年以上にわたって結びつけています.
- サイト1119のデータは,異なる気候システムの相互作用に関するユニークな視点を提供します.
関連する概念動画
What is Weather?
Overview
What is Climate?
Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, “Climate is what you expect. Weather is what you get.” Climate is influenced by geographic factors, such as latitude, terrain, and proximity to bodies of water.
Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.
Speciation Rates
Speciation can proceed at markedly different rates, and evolutionary biologists commonly describe these differences through the models of gradualism and punctuated equilibrium. Both patterns explain how new species arise, but they differ in the tempo and continuity of evolutionary change. In both cases, evolutionary change arises from heritable variation within populations, with natural selection often shaping traits that improve survival and reproduction under specific environmental conditions.
The Fossil Record
The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...
Microbes and Climate Change
Microorganisms are pivotal agents in Earth's biogeochemical cycles, significantly influencing climate dynamics through their metabolic activities. These microbes modulate the levels of key greenhouse gases by both contributing to and helping mitigate climate change.Microbial Contributions to Greenhouse Gas EmissionsRising global temperatures accelerate microbial metabolism, which, in turn, speeds up the decomposition of organic matter. This process releases carbon dioxide (CO₂) through...


