Glacial to Holocene Paleoceanographic and Continental Paleoclimate Reconstructions Based on ODP Site 1233/GeoB 3313 Off Southern Chile

Lamy, Frank; Kaiser, Jérôme

doi:10.1007/978-90-481-2672-9_6

Cited by 13 publications

(7 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When analysing cyclonic activity by the Eulerian method (kinetic energy), it is observed that positive anomalies in the Pacific and Atlantic indicate an increase in cyclonic activity (intensity), whose are more evident during the austral winter and spring for the El Niño period, while the negative anomalies of the kinetic energy, associated with the weakening of cyclonic activity, are observed during DJF and MAM for La Niña. According to Lamy and Kaiser (2009), during La Niña events the South Pacific Subtropical High becomes more intense and the STs are located south of 45°S, generating unfavourable conditions for precipitation to the north of this latitude, corroborating with our results, in particular in MAM. For the Indian Ocean, the results found are consistent with Reboita et al .…”

Section: Resultssupporting

confidence: 93%

Influence of El Niño‐Southern Oscillation on baroclinic instability and storm tracks in the Southern Hemisphere

Machado

Justino

Souza

2020

Intl Journal of Climatology

View full text Add to dashboard Cite

Earth's weather and climate are strongly influenced by synoptic scale systems such as extratropical cyclones. From this point of view, investigating the mechanisms associated with cyclogenesis, such as baroclinic instability (BI), which are defined by the thermal gradient and wind shear, are extremely important. However, atmospheric teleconnection patterns such as the El Niño-Southern Oscillation (ENSO) phenomenon may affect BI in the preferred region of extratropical cyclones, known as the storm track (ST) region. Therefore, the present study shows the impact of ENSO on BI and STs in the Southern Hemisphere. BI is determined by means of the Eady growth rate method, while the STs are calculated from the kinetic energy and by means of the meridional heat transport. In general, the results show that STs calculated from the BI and the kinetic energy show seasonal variability during ENSO events. This results in Southern Hemisphere extratropical cyclones being more intense with trajectories towards lower (higher) latitudes during El Niño (La Niña) summers. In contrast, little difference is seen in El Niño and La Niña winters. For the calculation of the meridional heat transport at 500 hPa, the Climate Forecast System Reanalysis produced weaker transport relative to ERA-Interim and previous studies.

show abstract

Section: Resultssupporting

confidence: 93%

Influence of El Niño‐Southern Oscillation on baroclinic instability and storm tracks in the Southern Hemisphere

Machado

Justino

Souza

2020

Intl Journal of Climatology

View full text Add to dashboard Cite

show abstract

“…Mix et al (2003) reported an 8-cm-thick dark ash layer of intermediate composition in the Ocean Drilling Program (ODP) site 1233, located 38 km offshore in more than 800 m water depth 260 km northwest from Michinmahuida Volcano. This layer has been dated between 10.5 and 11.0 ka BP (Lamy and Kaiser, 2009) and it has the highest magnetic susceptibility of the entire core at site 1233. However, glass chemistry for this tephra does not fit with Michinmahuida compositions (Table 2).…”

Section: Amarillo Ignimbritementioning

confidence: 99%

Holocene record of large explosive eruptions from Chaitén and Michinmahuida Volcanoes, Chile

Amigo¹,

Lara²,

Smith

2013

andgeo

View full text Add to dashboard Cite

ABSTRACT. Tephra fall deposits and one large ignimbrite close to Chaitén and Michinmahuida Volcanoes were analyzed for chemistry and radiocarbon dated to correlate the eruptive units and establish the timing of eruptions. These data suggest that both volcanoes were the source of large (VEI ≥5) and small to moderate (VEI <5) explosive eruptions throughout the Holocene. Four deposits are associated with volcanic activity from Chaitén Volcano, with two from Plinian eruptions at 9.9-9.5 and 5.3-4.9 (cal) ka BP that also generated pyroclastic density currents. The last event recognized from Chaitén (prior 2008) occurred a few hundred years ago, producing deposits that are similar to those of the 2008 eruption. All products from Chaitén are high-silica rhyolites; whole-rock compositions are indistinguishable but glass compositions are subtly different for some of the units. Seven deposits are related to eruptions of Michinmahuida Volcano, including a Plinian fall deposit at 7.6-7.3 ka BP and a large ignimbrite deposit at 10.5-10.2 ka BP. The chemical compositions of these products range from andesite to dacite. The last substantial explosive eruption event from Michinmahuida Volcano appears to have been a 0.5-0.3 ka BP sub-Plinian eruption, although younger scoria fall deposits likely derived from local pyroclastic cones are also found. Both volcanoes pose a wide variety of potential hazards to the region ranging from those derived from ignimbrite-forming eruptions to pyroclastic-cone formation. Valleys adjacent to the volcanoes were the areas most heavily affected by volcanic activity, because they were inundated by pyroclastic density currents and lahars. However, even regions located tens of kilometers east and north of the volcanoes experienced accumulations of tephra, which could harm both agriculture and infrastructure if similar events occurred today. RESUMEN. Registro de erupciones explosivas holocenas de los volcanes Chaitén y Michinmahuida, Chile. En las cercanías de los volcanes Chaitén y Michinmahuida se han estudiado un conjunto de depósitos piroclásticos de caída y un depósito ignimbrítico. Estos se han caracterizado mediante análisis químico (de roca total y microsonda en vidrio volcánico) y datados por medio de isótopos de radiocarbono. De esta forma, se ha establecido una nueva cronología eruptiva para estos centros. Los datos obtenidos sugieren que ambos volcanes presentan conspicua actividad explosiva durante el Holoceno de variada magnitud. En particular, se han identificado depósitos de al menos cuatro erupciones asociadas al volcán Chaitén, incluyendo dos Plinianos ocurridas entre 9.9-9.5 y 5.3-4.9 ka antes del presente, que generaron, además, corrientes piroclásticas en los valles adyacentes. El evento más reciente identificado para este volcán, corresponde a una erupción de similar magnitud a la del 2008 y habría ocurrido unos tres siglos antes del presente. Para este volcán, todos sus productos piroclásticos corresponden a riolitas, cuyas composiciones de roca total resultan prácticamente indi...

show abstract

“…Drier conditions during the early to mid-Holocene have also been documented at Abarzúa et al, 2004;Moreno, 2004;Moreno and León, 2003). Sedimentary records from oceanic, fjord and lake sites from southern, central and northern Chile indicate widespread warming at southern hemisphere mid-latitudes between 490 12.5 and 8.5 cal ka BP (Lamy and Kaiser, 2009;Fletcher andMoreno, 2011, 2012;Kaiser et al, 2008;Kim et al, 2002;Lamy et al, 2010).…”

Section: Paleoclimate Implicationsmentioning

confidence: 90%

Volcanism and climate change as drivers in Holocene depositional dynamic of Laguna del Maule (Andes of central Chile – 36° S)

Frugone-Álvarez¹,

Latorre²,

Barreiro-Lostres³

et al. 2020

Preprint

View full text Add to dashboard Cite

Abstract. Late Quaternary volcanic basins are active landscapes from which detailed archives of past climate, seismic and volcanic activity can be obtained. A multidisciplinary study performed on a transect of sediment cores was used to reconstruct the depositional evolution of the high-elevation Laguna del Maule (LdM) (36° S, 2180 m asl, Chilean Andes). The recovered 5 m composite sediment sequence includes two thick turbidite units (LT1 and LT2) and numerous tephra layers (23 ash and 6 lapilli). We produced an age model is based on nine new 14C AMS date, existing 210Pb and 137Cs data and the Quizapú ash horizon (CE 1932). According to this age model, early Holocene were followed by a phase of increased productivity during the mid Holocene and higher lake levels after 4.0 ka BP. Major hydroclimate transitions occurred at ca. 0.5, 4.0, 8.0 and 11 ka BP. Decreased summer insolation and winter precipitation due to a southward shift in the Southern Westerly Winds and a strengthened Pacific Subtropical High could explain early Holocene lower lake levels. Increased biological productivity during the mid-Holocene (~ 8.0 to 6.0 ka) is coeval with a warm-dry phase described for much of southern South America. Periods of higher lake productivity are synchronous to higher frequency of volcanic events. During the late Holocene, the tephra layers shows compositional changes suggesting a transition from silica-rich to silica-poor magmas at around 4.0 cal ka BP. This transition was synchronous with increased variability of sedimentary facies and geochemical proxies, indicating higher lake levels and increased moisture at LdM after 4.0 cal ka BP, most likely caused by the inception of current ENSO/PDO-like dynamics in central Chile.

show abstract

Glacial to Holocene Paleoceanographic and Continental Paleoclimate Reconstructions Based on ODP Site 1233/GeoB 3313 Off Southern Chile

Cited by 13 publications

References 90 publications

Influence of El Niño‐Southern Oscillation on baroclinic instability and storm tracks in the Southern Hemisphere

Influence of El Niño‐Southern Oscillation on baroclinic instability and storm tracks in the Southern Hemisphere

Holocene record of large explosive eruptions from Chaitén and Michinmahuida Volcanoes, Chile

Volcanism and climate change as drivers in Holocene depositional dynamic of Laguna del Maule (Andes of central Chile – 36° S)

Contact Info

Product

Resources

About