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Relative paleoenvironmental adjustments following deglaciation of the Byers Peninsula (Livingston Island, Antarctica)
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Orientador(es)
Resumo(s)
In the present context of fast warming in the Antarctic Peninsula (AP), understanding
past and recent environmental dynamics is crucial to better assess future environmental
responses in this region. Very detailed geomorphological maps can help to interpret
the interaction between glacial, periglacial, and paraglacial systems. The Holocene environmental
sequence on Byers Peninsula, an ice-free area in the westernmost part of
Livingston Island (Maritime Antarctica), is still poorly understood. This paper focuses
on the geomorphology of the Cerro Negro, a volcanic plug located on the southeast
fringe of this peninsula. The distribution of landforms and deposits generated by different
geomorphological processes provides insights into the Holocene environmental
dynamics on Byers Peninsula. During the fieldwork campaign in January 2014, an accurate
geomorphological map of Cerro Negro and its surroundings was generated. Four
geomorphological environments were identified: hill, north slope, southern escarpment,
and marine terraces and present-day beach. Periglacial landforms are abundant, especially
patterned ground features (blockstreams, sorted stone circles, stone stripes). All these
cryoturbation landforms, except blockstreams, are active under present-day climate conditions.
In addition to a sequence of Holocene marine terraces and slope deposits, such
as talus cones and rockfalls, there is a glacial moraine adjoining the northern slope of
the hill. From the morphostratigraphic correlation between the active and inactive landforms,
we infer three main phases describing the paleoenvironmental evolution in this
area: (1) maximum glacial expansion; (2) Holocene glacial retreat, lake formation, and
intense periglacial dynamics; and (3) deglaciation of the Byers Peninsula and widespread
periglacial processes. The Cerro Negro has been a nunatak for most of the Holocene;
the lake located near the summit of this hill appeared when most of the Byers Peninsula
was still covered by glacial ice. This study constitutes an example of how an accurate
geomorphological characterization of a small area can complement other approaches
to generate a better understanding of the paleoenvironmental evolution in the region.
Descrição
Palavras-chave
Paleoenvironmental adjustments Deglaciation Byers Peninsula Livingston Island Antarctica
Contexto Educativo
Citação
Ruiz-Fernandez, J., & Oliva, M. (2016). Relative paleoenvironmental adjustments following deglaciation of the Byers Peninsula (Livingston Island, Antarctica). Arctic, Antarctic, and Alpine Research, 48(2), 345–359. https://doi.org/10.1657/AAAR0015-014
Editora
Taylor & Francis