Scholarlink

<p>Long-term hydroclimate records from the Amazon Basin are scarce, limiting our understanding of how this climatically critical region responded to Pleistocene climate changes. Here we present a 1.93-million-year reconstruction of hydroclimate variability in the western Amazonia and the tropical Andes, derived from titanium-to-calcium and iron-to-potassium ratios of a marine sediment core collected offshore the Amazon River mouth. These geochemical proxies reveal a long-term trend toward wetter conditions through the Pleistocene, particularly after approximately 650,000 years ago. Glacial intervals are characterized by higher proxy variability and more frequent high-amplitude excursions, likely reflecting bundled humid episodes associated with southward shifts of the Intertropical Convergence Zone during North Atlantic cold events, rather than uniformly wetter mean conditions. Temperature-driven processes, including Andean glacial erosion, may also contribute to the geochemical signals. These findings suggest that western Amazonian hydroclimate is sensitive to high-latitude forcing on both millennial and orbital timescales.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

A two-million-year record reveals long-term increase in precipitation over western Amazonia and the tropical Andes

  • 期刊论文

  • 出版模式：

    开放获取

  • 发表日期：

    2026年5月20日

查看全文
  • Allan Sandes de Oliveira,
  • Cleverson Guizan Silva,
  • Fabrício Ferreira,
  • Cristiano Mazur Chiessi,
  • Sherilyn C. Fritz,
  • Gary S. Dwyer,
  • Andrea Kern,
  • Catherine A. Rigsby,
  • Rodrigo da C. Portilho-Ramos,
  • Ana Luiza Spadano Albuquerque,
  • Marcus V. L. Kochhann,
  • James Broda,
  • Liviu Giosan,
  • Paul A. Baker

摘要

Long-term hydroclimate records from the Amazon Basin are scarce, limiting our understanding of how this climatically critical region responded to Pleistocene climate changes. Here we present a 1.93-million-year reconstruction of hydroclimate variability in the western Amazonia and the tropical Andes, derived from titanium-to-calcium and iron-to-potassium ratios of a marine sediment core collected offshore the Amazon River mouth. These geochemical proxies reveal a long-term trend toward wetter conditions through the Pleistocene, particularly after approximately 650,000 years ago. Glacial intervals are characterized by higher proxy variability and more frequent high-amplitude excursions, likely reflecting bundled humid episodes associated with southward shifts of the Intertropical Convergence Zone during North Atlantic cold events, rather than uniformly wetter mean conditions. Temperature-driven processes, including Andean glacial erosion, may also contribute to the geochemical signals. These findings suggest that western Amazonian hydroclimate is sensitive to high-latitude forcing on both millennial and orbital timescales.