モンゴル高原東部ブイル湖の湖底堆積物を用いた過去100年間の環境変動解析

DOI 機関リポジトリ HANDLE オープンアクセス

書誌事項

タイトル別名
  • Environmental changes over the last 100 years using a sediment core of Lake Buir in the eastern Mongolian Plateau

抄録

This study investigated a short sediment core Buir-2 with total length of 49 cm, retrieved from Lake Buir in the eastern Mongolian Plateau. The sediment core was dated at 1901-2020 CE based on the 137Cs-210Pb ages. The turbidite bed with the core depth of 22-35 cm was detected from the grain size composition. Since the depositional age was dated at 1955 ± 5 CE, the deposition possibly marks an episode of tectonic activations, such as 1957 CE (M=7.8) Muisk events, northeastern Lake Baikal and 1957 CE (M=8.1) Gobi-Altai earthquake, southern Mongolia. After removing the turbidite bed from the geochemical records of Lake Buir sediment core, we obtained the turbidite-removed temporal records. The σ13C of total organic carbon (TOC) and TOC/ total nitrogen molar ratio indicates that the organic matters of Buir-2 core are dominated by phytoplankton, the ratio of which has increased since 1901 CE following the decrease in precipitation. Biogenic silica (BioSi) and TOC contents, reflecting the biological production of the lake, have been increased since 1955 CE following the increase in annual mean temperature. Similarly, the carbonate contents show a progressive increasing trend since 1955 CE, probably due to the aridification in this region.

収録刊行物

関連プロジェクト

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ