ENSO variability in the last interglacial estimated from high resolution XRF records of laminated marine sediments from Peru
Abstract
El Niño-Southern Oscillation (ENSO) is the main source of climate variability in the SE Pacific region with effects in both land and ocean. Documenting the response of ENSO to past abrupt global warming events is required to understand the sensitivity of ENSO to changing climate. Here we present a comparison of ENSO-related interannual variability in the Holocene, the deglaciation and the last interglacial warm period (MIS5e), based on the analysis of marine sediments from Peru. We used the ODP 686A sediment core, located at 13°S off Peru and at 400 m depth in the continental margin, which presents triplet laminations at sub-millimeter scale with silt-rich/clay-rich couplets and diatom ooze laminae. XRF analysis and organic matter analysis (TOC, δ13C, δ15N) were hold in the subsamples along the upper 27 m of the core, representing the last 130 000 years. Short laminate sediment sections (10-15 cm) were scanned with high resolution XRF (every 50 μm). This let us to identify clear cycles in terrigenous material at millimeter scale. The time resolution was determined from a precise 14C age-depth model for the Holocene period. The ENSO-related interannual variability of river discharge (as indicated by Ti content) was calculated using a 2-7 years band-pass filter. Results indicate a large centennial to millennial scale changes with periods of strong ENSO precipitation variability during the MIS5e.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMOS0150011C
- Keywords:
-
- 3305 Climate change and variability;
- ATMOSPHERIC PROCESSES;
- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 4215 Climate and interannual variability;
- OCEANOGRAPHY: GENERAL;
- 4922 El Nino;
- PALEOCEANOGRAPHY