Tropical climate changes at millennial and orbital timescales on the bolivian Altiplano


Abstract:

Tropical South America is one of the three main centres of the global, zonal overturning circulation of the equatorial atmosphere (generally termed the 'Walker' circulation1). Although this area plays a key role in global climate cycles, little is known about South American climate history. Here we describe sediment cores and down-hole logging results of deep drilling in the Salar de Uyuni, on the Bolivian Altiplano, located in the tropical Andes. We demonstrate that during the past 50,000 years the Altiplano underwent important changes in effective moisture at both orbital (20,000-year) and millennial timescales. Long-duration wet periods, such as the Last Glacial Maximum - marked in the drill core by continuous deposition of lacustrine sediments - appear to have occurred in phase with summer insolation maxima produced by the Earth's precessional cycle. Short-duration, millennial events correlate well with North Atlantic cold events, including Heinrich events 1 and 2, as well as the Younger Dryas episode. At both millennial and orbital timescales, cold sea surface temperatures in the high-latitude North Atlantic were coeval with wet conditions in tropical South America, suggesting a common forcing.

Año de publicación:

2001

Keywords:

    Fuente:

    scopusscopus

    Tipo de documento:

    Article

    Estado:

    Acceso restringido

    Áreas de conocimiento:

    • Paleoclimatología
    • Cambio climático
    • Geografía

    Áreas temáticas de Dewey:

    • Factores que afectan al comportamiento social
    • Geología, hidrología, meteorología
    Procesado con IAProcesado con IA

    Objetivos de Desarrollo Sostenible:

    • ODS 13: Acción por el clima
    • ODS 15: Vida de ecosistemas terrestres
    • ODS 6: Agua limpia y saneamiento
    Procesado con IAProcesado con IA