A new multi-proxy record of environmental change over the last 1000 years on Chiloé Island: Lake Pastahué, south-central Chile (42°S)

Knowledge of past environmental and climatic conditions of lake ecosystems on Chiloé Island on a millennial scale is limited. Hence, this study fills a gap in our understanding of this part of southern Chile. The aim of this study was to reconstruct the environmental and climatic history of the last 1000 years of Lake Pastahué through a multi-proxy sediment core analysis. The 1-m-long core was subsampled every centimeter for the organic matter, magnetic susceptibility, grain-size distribution, and biological indicator (pollen, chironomids) analyses. The age model was constructed from 210Pb, 137Cs, and 14C activity. Pollen results revealed a North Patagonian forest composition represented by Nothofagus, Weinmannia, Drimys, Tepualia, Myrtaceae, Poaceae, and Pteridophyta. The abundance of Rumex and Pinus in the most recent part of the pollen assemblage reflects a clear anthropogenic impact. The sedimentological parameters and chironomid assemblage show similar variations, which highlight changes in the trophic state of the lake. The changes observed in all proxies suggest the influence of climate events such as the ‘Medieval Climate Anomaly’ (MCA) and ‘Little Ice Age’ (LIA). The variations observed since the beginning of the 20th century could be the result of the combined effect of anthropogenic activities and the increase in temperature recorded in south-central Chile and Patagonia.

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Broad-Scale Surface and Atmospheric Conditions during Large Fires in South-Central Chile

Fire ◽

10.3390/fire4020028 ◽

2021 ◽

Vol 4 (2) ◽

pp. 28

Author(s):

David B. McWethy ◽

René D. Garreaud ◽

Andrés Holz ◽

Gregory T. Pederson

Keyword(s):

Climatic Conditions ◽

Atmospheric Conditions ◽

Easterly Wind ◽

Central Chile ◽

Area Burned ◽

Active Fire ◽

South Central ◽

Surface Temperatures ◽

Westerly Winds ◽

Large Fires

The unprecedented size of the 2017 wildfires that burned nearly 600,000 hectares of central Chile highlight a need to better understand the climatic conditions under which large fires develop. Here we evaluate synoptic atmospheric conditions at the surface and free troposphere associated with anomalously high (active) versus low (inactive) months of area burned in south-central Chile (ca. 32–41° S) from the Chilean Forest Service (CONAF) record of area burned from 1984–2018. Active fire months are correlated with warm surface temperatures, dry conditions, and the presence of a circumpolar assemblage of high-pressure systems located ca. 40°–60° S. Additionally, warm surface temperatures associated with active fire months are linked to reduced strength of cool, onshore westerly winds and an increase in warm, downslope Andean Cordillera easterly winds. Episodic warm downslope winds and easterly wind anomalies superimposed on long-term warming and drying trends will continue to create conditions that promote large fires in south-central Chile. Identifying the mechanisms responsible for easterly wind anomalies and determining whether this trend is strengthening due to synoptic-scale climatic changes such as the poleward shift in Southern Hemisphere westerly winds will be critical for anticipating future large fire activity in south-central Chile.

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INFLUENCE OF GEOLOGICAL PROCESSES IN THE COSMOVISION OF THE MAPUCHE NATIVE PEOPLE IN SOUTH CENTRAL CHILE

Earth Sciences History ◽

10.17704/1944-6187-40.2.581 ◽

2021 ◽

Vol 40 (2) ◽

pp. 581-606

Author(s):

C.A. BASTÍAS ◽

R. CHARRIER ◽

C.V. MILLACURA ◽

L. AGUIRRE ◽

F. HERVÉ ◽

...

Keyword(s):

Active Continental Margin ◽

Climatic Conditions ◽

Native People ◽

South American ◽

Central Chile ◽

Tsunami Waves ◽

Geological Processes ◽

South Central ◽

The Earth ◽

Tectonic Environment

We present an interpretation of how natural geological and meteorological events influenced the cosmovision of the Mapuche people from south-central Chile. These events resulted from the geodynamic conditions and related processes occurring along the South American active continental margin and the climatic conditions in the region. Their influence on the Mapuche cosmovision is clearly reflected in the most important myths and legends of the Mapuche acquired knowledge. One particularly illustrative myth refers to the combat between two huge snakes, Trentrén and Kaikai. Kaikai, representing the ocean, continuously tries to encroach upon the earth, and Trenten, representing the earth, opposes Kaikai by uplifting the ground to save the inhabitants. This is interpreted as an allegory for what happens during earthquakes when the back-and-forth movement of tsunami waves makes it appear as if the earth sinks and uplifts. Several hills named Trentrén are topographic heights that people can climb to be safe from the effects of the tsunamis. Other myths and legends refer to other characteristic geological phenomena in this particularly active tectonic environment. This article illustrates how the mythical interpretation of geological events configured the understanding of the surrounding world and produced the exquisite body of myths and legends in the Mapuche culture.

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Intertidal zonation patterns of macroinfauna over a range of exposed sandy beaches in south-central Chile

Marine Ecology Progress Series ◽

10.3354/meps101105 ◽

1993 ◽

Vol 101 ◽

pp. 105-118 ◽

Cited By ~ 57

Author(s):

E Jaramillo ◽

A McLachlan ◽

P Coetzee

Keyword(s):

Sandy Beaches ◽

Central Chile ◽

South Central ◽

Intertidal Zonation ◽

Zonation Patterns

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Cardiorespiratory Fitness: Reference on the Six-Minute Walk Test and Oxygen Consumption in Adolescents from South-Central Chile

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18052474 ◽

2021 ◽

Vol 18 (5) ◽

pp. 2474

Author(s):

Jaime Vásquez-Gómez ◽

Nelson Gatica Salas ◽

Pedro Jiménez Villarroel ◽

Luis Rojas-Araya ◽

Cesar Faundez-Casanova ◽

...

Keyword(s):

Cardiorespiratory Fitness ◽

Reference Values ◽

Estimation Error ◽

Walk Test ◽

Central Chile ◽

Six Minute Walk Test ◽

Body Adiposity ◽

South Central ◽

Males And Females ◽

Minute Walk

Cardiorespiratory fitness (CRF) provides oxygen to the exercising muscles and is related to body adiposity, with cardiometabolic variables. The aim was to develop reference values and a predictive model of CRF in Chilean adolescents. A total of 741 adolescents of both genders (15.7 years old) participated in a basic anthropometry, performance in the six-minute walk test (SMWT), and in Course Navette was measured. Percentiles were determined for the SMWT, for the V̇O2max, and an equation was developed to estimate it. The validity of the equation was checked using distribution assumptions and the Bland–Altman diagram. The STATA v.14 program was used (p < 0.05). The 50th percentile values for males and females in the SMWT and in the V̇O2max of Course Navette were, respectively, from 607 to 690 and from 630 to 641 m, and from 43.9 to 45 and from 37.5 to 31.5 mlO2·kg·min−1, for the range of 13 to 17 years. For its part, the model to predict V̇O2max incorporated gender, heart rate, height, waist-to-height ratio (WHR), and distance in the SMWT (R2 = 0.62; estimation error = 0.38 LO2·min−1; p <0.001). Reference values can guide physical fitness in Chilean adolescents, and V̇O2max was possible to predict from morphofunctional variables.

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