Giant's footprint

El Niño variability off Peru during the last 20,000 years

Here we present a high-resolution marine sediment record from the El Nino region off the coast of Peru spanning the last 20,000 years. Sea surface temperature, photosynthetic pigments, and a lithic proxy for El Nino flood events on the continent are used as paleo–El Nino–Southern Oscillation proxy data. The onset of stronger El Nino activity in Peru started around 17,000 calibrated years before the present, which is later than modeling experiments show but contemporaneous with the Heinrich event 1. Maximum El Nino activity occurred during the early and late Holocene, especially during the second and third millennium B.P. The recurrence period of very strong El Nino events is 60–80 years. El…

A quantitative high-resolution summer temperature reconstruction based on sedimentary pigments from Laguna Aculeo, central Chile, back to AD 850

We present a pigment-based quantitative high-resolution (five years) austral summer DJF (December to February) temperature reconstruction for Central Chile back to AD 850. We used non-destructive in situ multichannel reflection spectrometry data from a short sediment core of Laguna Aculeo (33°50′S/70°54′W, 355 m a.s.l., central Chile). Calibration-in-time (period AD 1901—2000, cross-validated with split periods) revealed robust correlations between local DJF temperatures and total sedimentary chlorin (relative absorption band depth (RABD) centred in 660—670 nm RABD660;670: r=0.79, P<0.01; five-years triangular filtered) and the degree of pigment diagenesis ( R660nm/670 nm: r=0.82, P<…

A late Eemian aridity pulse in central Europe during the last glacial inception

How do ice ages begin? It's an obvious question to ask as we enjoy the relative luxury of an interglacial, but a hard one to answer. A look at past transitions may give some clues as to how this period will one day come to an end. A climate reconstruction based on sediments found beneath a lake in the Eifel mountains in Germany provides evidence of an extreme climate event lasting 468 years right at the end of the last interglacial. Dust storms, aridity, bushfires and the loss of trees associated with a warm climate coincided with a southward shift of the warm waters of the North Atlantic drift. In terms of insolation — the rate of delivery of the Sun's radiation to Earth — conditions then …

In-situ reflectance spectroscopy - analysing techniques for high-resolution pigment logging in sediment cores

The temporal resolution of marine proxy data is limited by analytically required sample size. We present in-situ reflectance spectroscopy techniques (usually applied in remote sensing) to analyse the organic fraction of marine and terrestrial sediment. From absorption band depths, photosynthesis pigment variations are derived for sediments from the upwelling region off Peru, where productivity is related to the annual variability of El Nino strength. Quantitative estimations of diagenetic photosynthesis pigments derived from absorption band analysis in reflectance spectra are highly correlated to organic carbon content. The ratio of pigment fractions is related to chlorine concentration and…

10. Holocene and Eemian varve types of Eifel maar lake sediments

Abstract Varves of the Holocene and of the last interglacial were investigated in two sediment sequences from Eifel maar lakes. The modern maar with Schalkenmehrener Maar Lake and the dry maar lake West Hoher List have the same size, are two kilometres apart at the same altitude, but the Eemian lake was much deeper. The sediments of both lakes are dominated by autochthonous sediments, mainly from diatom-dominated algae. Differences in the palaeoproductivity and in calcite precipitation are probably not climatically controlled but due to lake basin morphometry and the carbonate reservoir in the catchment areas. The occurrence of dry periods with aeolian dust deposition during the last interg…

Rapid climate change during the early Holocene in western Europe and Greenland

Based on microfacies analyses of seasonally laminated varved sediments from lake Holzmaar, Germany, we report evidence of decadal-to century-scale climate variability during the early Holocene. The shifts in climate are documented in the thickness variations and changes in the composition of the varves in response to subtle shifts in limnological conditions. The close similarity between the Holzmaar varve record and the GRIP oxygen isotope record during 7.4-9.0 calendar (cal.) ka suggests that the high frequency climatic variations in both regions were controlled by the same mechanism. Our more detailed studies covering the central 409-yr period (∼7.846-8.255 cal. ka, encompassing the 8.2 …

How do the 1982/83 and 1997/98 El Niños rank in a geological record from Peru?

Two very strong El Nino events during the years 1982/83 and 1997/98 caused dramatic economical and social damages worldwide. However, it is quite uncertain how these events rank in a long-term perspective and how frequent events of similar magnitude were in the past. Very-high-resolution proxy data for flood events in the El Nino key region of Peru are presented. Strong flood events in the hyper-arid northern and northern central Peru coastal desert occur during El Nino events. The flood data are derived from a laminated marine sediment core. The proxy data reveal that both modern events were recorded as the strongest sediment discharges in the 106KL flood record over the last millennium. S…

A major Holocene ENSO anomaly during the Medieval period

[1] Here, we present a high resolution marine El Nino flood record from Peru. A period of extreme drought without strong flooding occurred from A.D. 800–1250. Anomalous precipitation patterns characterized the entire Indo-Pacific ENSO domain, with dry events in the northern Arabian Sea and the mid-latitudes of both Americas, coinciding with wet periods in the Atlantic Cariaco Basin. The occurrence of contemporaneous moisture anomalies in other archives in the ENSO region highlights the role of El Nino strength in global climate evolution during the late Medieval period when temperature reconstructions show a rather heterogeneous pattern.

(Table 1) Age determination of sediment core SO147_106KL

Here we present a high-resolution marine sediment record from the El Niño region off the coast of Peru spanning the last 20,000 years. Sea surface temperature, photosynthetic pigments, and a lithic proxy for El Niño flood events on the continent are used as paleo-El Niño-Southern Oscillation proxy data. The onset of stronger El Niño activity in Peru started around 17,000 calibrated years before the present, which is later than modeling experiments show but contemporaneous with the Heinrich event 1. Maximum El Niño activity occurred during the early and late Holocene, especially during the second and third millennium B.P. The recurrence period of very strong El Niño events is 60-80 years. El…

Record of pollen, silt and greyscale stack from the Eifel Laminated Sediment Archive (ELSA)

Investigating the processes that led to the end of the last interglacial period is relevant for understanding how our ongoing interglacial will end, which has been a matter of much debate. A recent ice core from Greenland demonstrates climate cooling from 122,000 years ago driven by orbitally controlled insolation, with glacial inception at 118,000 years ago. Here we present an annually resolved, layer-counted record of varve thickness, quartz grain size and pollen assemblages from a maar lake in the Eifel (Germany), which documents a late Eemian aridity pulse lasting 468 years with dust storms, aridity, bushfire and a decline of thermophilous trees at the time of glacial inception. We inte…