Holocene tephrochronology record of large explosive eruptions in the southernmost Patagonian Andes

Stern, Charles R.

doi:10.1007/s00445-007-0148-z

Cited by 183 publications

(247 citation statements)

References 32 publications

Supporting

Mentioning

202

Contrasting

Unclassified

Order By: Relevance

“…Recognition of anomalous thickening patterns is most likely in deposits from large eruptions dispersed over land (e.g. Stern 2008) that are well exposed and sampled on spatial scales of a few kilometres or less. Even in such instances, depositional complexities arising from atmospheric processes (whether it be turbulence, aggregation or within-cloud convective instabilities) may still obscured by the overlap of deposits from multiple eruptive phases (i.e.…”

Section: Implications and Further Discussionmentioning

confidence: 99%

An example of enhanced tephra deposition driven by topographically induced atmospheric turbulence

et al. 2015

View full text Add to dashboard Cite

Spatial variations in the thickness and grain-size characteristics of tephra fall deposits imply that tephra depositional processes cannot be fully captured by models of single-particle sedimentation from the base of the eruption plume. Here, we document a secondary thickness maximum in a ∼9.75 ka tephra fall deposit from Chaitén volcano, Chile (Cha1 eruption). This secondary thickness maximum is notably coarser-grained than documented historical examples, being dominated by medium-grained ash, and an origin via particle aggregation is therefore unlikely. In the region of secondary thickening, we propose that high levels of atmospheric turbulence accelerated particles held within the mid-to lower-troposphere (0 to ∼6 km) towards the ground surface. We suggest that this enhancement in vertical atmospheric mixing was driven by the breaking of lee waves, generated by winds passing over elevated topography beneath the eruption plume. Lower atmospheric circulation patterns may exert a significant control on the dispersal and deposition of tephra from eruption plumes across all spatial scales, particularly in areas of complex topography.

show abstract

Section: Implications and Further Discussionmentioning

confidence: 99%

An example of enhanced tephra deposition driven by topographically induced atmospheric turbulence

et al. 2015

View full text Add to dashboard Cite

show abstract

“…3). Stern (2008) and Sagredo et al (2011) reported nearly the same ages. According to the new age-depth model, the depth of 14.7 m (cd-ec) has an age of 15 102 cal BP well within the reported age range of the Reclús R 1 tephra, whereas the previous model gives a considerably older age of 16 034 cal BP (Kliem et al, 2013b).…”

Section: Age-depth Modelmentioning

confidence: 72%

Climate history of the Southern Hemisphere Westerlies belt during the last glacial–interglacial transition revealed from lake water oxygen isotope reconstruction of Laguna Potrok Aike (52° S, Argentina)

Zhu¹,

Lücke²,

Wissel³

et al. 2014

Clim. Past

View full text Add to dashboard Cite

Abstract. The Southern Hemisphere Westerlies (SHW) play a crucial role in large-scale ocean circulation and global carbon cycling. Accordingly, the reconstruction of how the latitudinal position and intensity of the SHW belt changed during the last glacial termination is essential for understanding global climatic fluctuations. The southernmost part of the South American continent is the only continental mass intersecting a large part of the SHW belt. However, due to the scarcity of suitable palaeoclimate archives continuous proxy records back to the last glacial are rare in southern Patagonia. Here, we show an oxygen isotope record from cellulose and purified bulk organic matter of submerged aquatic moss shoots from Laguna Potrok Aike (52 • S, 70 • W), a deep maar lake located in semi-arid, extra-Andean Patagonia, covering the last glacial-interglacial transition (26 000 to 8500 cal BP). Based on the highly significant correlation between oxygen isotope values of modern aquatic mosses and their host waters and abundant well-preserved moss remains in the sediment record a high-resolution reconstruction of the lake water oxygen isotope (δ 18 O lw−corr ) composition is presented. The reconstructed δ 18 O lw−corr values for the last glacial are ca. 3 ‰ lower than modern values, which can best be explained by generally cooler air temperatures and changes in the moisture source area, together with the occurrence of permafrost leading to a prolonged lake water residence time. Thus, the overall glacial δ 18 O lw−corr level until 21 000 cal BP is consistent with a scenario of weakened or absent SHW at 52 • S compared to the present. During the last deglaciation, reconstructed δ 18 O lw−corr values reveal a significant two-step rise describing the detailed response of the lake's hydrological balance to this fundamental climatic shift. Rapid warming is seen as the cause of the first rise of ca. 2 ‰ in δ 18 O lw−corr during the first two millennia of deglaciation (17 600 to 15 600 cal BP) owing to more 18 O enriched precipitation and increasing temperature-induced evaporation. Following this interpretation, an early strengthening of the SHW would not be necessary. The subsequent decrease in δ 18 O lw−corr by up to 0.7 ‰ marks a millennial-scale transition period between 15 600 and 14 600 cal BP interpreted as the transition from a system driven by temperature-induced evaporation to a system more dominated by wind-induced evaporation. The δ 18 O lw−corr record resumes its pronounced increase around 14 600 cal BP. This further cumulative enrichment in 18 O of lake water could be interpreted as response to strengthened wind-driven evaporation as induced by the intensification and establishment of the SHW at the latitude of Laguna Potrok Aike (52 • S) since 14 600 cal BP.

show abstract

“…Small (<3 mm) pumice grains are widespread in LFA-D. Trace-element geochemical analysis of these grains indicate that they are similar to pumice and bulk tephra derived from explosive eruptions of the Reclus volcano (Table 1; Stern 1990Stern , 2004Stern and 2008, the nearest volcano in the region located ~30 km west of Torres del Paine and ~75 km west of the El Canal section. Interpretation: Grounding-line subaqueous fan.…”

Section: Lithofacies Association D (Facies Codesmentioning

confidence: 90%

“…Our method allowed us to define eight different LFA that comprise subglacial, subaquatic, and subaerial glacigenic sediments. We also sampled small pumice grains embedded within El Canal sediments for ICP-MS trace-element geochemical analysis both in order to identify provenance and to constrain the tephrochronologic context for sediments in El Canal by comparison with the products of dated eruptions from nearby volcanoes (Stern, 2008;Stern et al, 2011).…”

Section: Methodsmentioning

confidence: 99%

Ambientes glaciolacustres y construcción estructural de morrenas frontales tardiglaciales en Torres del Paine, Patagonia austral chilena.

Garcı́a

Strelin

Vega

et al. 2015

Andgeo

Self Cite

View full text Add to dashboard Cite

ABSTRACT. The late-glacial sedimentologic and geomorphic record of the former Patagonian ice sheet remains mostly unstudied despite the fact that it affords invaluable evidence for glaciologic processes during the last glacial-interglacial transition (i.e., 18-11.5 ka). This information is critical if landforms (e.g., moraines) and associated sediments are to be used for paleoclimate reconstruction. El Canal stratigraphic section in Torres del Paine, southern Chile (51ºS), provides one of the few complete late-glacial morphostratigraphic records preserved on land in Patagonia that has not been reworked by postglacial lake or marine transgressions. Therefore, it provides unique evidence for reconstructing former environments, processes and fluctuations along the ice front at the end of the last glaciation. Here, we present results of a morphostratigraphic study of this site, which was shaped during the late-glacial Torres del Paine-TDP II, III and IV glacier fluctuations. We document the presence of eight sediment lithofacies associations and six stratigraphic sections that expose a complete record of proximal to distal subaqueous processes, which we link to phases of glacier advance (e.g., moraine building) and retreat. During the late-glacial, the Lago del Toro ice lobe pushed and glaciotectonized ice-contact lake sediments several times to shape the TDP moraine ridges fringing present-day lake. The saw-toothed morphology of the ridges confirms the structural origin of these landforms. Based on sediment facies associations, we conclude that local glacial lakes developed along the ice front during deposition of the late-glacial TDP II-IV moraine belts, suggesting that collapse, and associated continental drainage diversion, of major regional-size lakes in Torres del Paine had occurred during this time.

show abstract

Holocene tephrochronology record of large explosive eruptions in the southernmost Patagonian Andes

Cited by 183 publications

References 32 publications

An example of enhanced tephra deposition driven by topographically induced atmospheric turbulence

An example of enhanced tephra deposition driven by topographically induced atmospheric turbulence

Climate history of the Southern Hemisphere Westerlies belt during the last glacial–interglacial transition revealed from lake water oxygen isotope reconstruction of Laguna Potrok Aike (52° S, Argentina)

Ambientes glaciolacustres y construcción estructural de morrenas frontales tardiglaciales en Torres del Paine, Patagonia austral chilena.

Contact Info

Product

Resources

About