Dissertação

{pt_PT=Utilização de elementos químicos como traçadores climáticos e de transporte a longa distância em lagos na Antártida} {} EVALUATED

{pt=Antarctica is the most isolated continent, it comprises an area of about 14 million km2 and about 99.6% of its surface is covered by ice. Within the ice-free areas of Maritime Antarctica lies the Byers Peninsula, at the western end of Livingston Island. The Byers peninsula is the largest ice-free area of the South Shetland archipelago, with an area of approximately 60 km2. In the present dissertation we tried to understand the use of chemical elements as indicators of phenomena of long distance transport and climate. For this, 99 samples of sediments of three lakes, Escondido, Cerro Negro and Domo, were evaluated for the presence of trace elements (As, Cd, Pb, Co, Cu, Cr, Mn, Ni, V, Zn). The concentration of trace elements was determined by ICP-MS in the IPMA. The trace elements studied seem to begood long-distance transport indicators, namely eruptive events, namely of eruptive events, since their concentration increases when tephras occur. On the other hand, in the lake records of Byers Peninsula they have not reported clear climatic signals, as they have not translated a behaviour that allows translating climatic phenomena. The C / N ratio is, however, a good climatic indicator showing a growth trend, meeting the trend of temperature increase in the peninsula. Sediments samples provide better conditions to study long distance transport and climate phenomena as they are a result of long term deposition and this way provide higher concentration increments, when compared to water samples. , en=Antarctica is the most isolated continent, it comprises an area of about 14 million km2 and about 99.6% of its surface is covered by ice. Within the ice-free areas of Maritime Antarctica lies the Byers Peninsula, at the western end of Livingston Island. The Byers peninsula is the largest ice-free area of the South Shetland archipelago, with an area of approximately 60 km2. In the present dissertation we tried to understand the use of chemical elements as indicators of phenomena of long distance transport and climate. For this, 99 samples of sediments of three lakes, Escondido, Cerro Negro and Domo, were evaluated for the presence of trace elements (As, Cd, Pb, Co, Cu, Cr, Mn, Ni, V, Zn). The concentration of trace elements was determined by ICP-MS in the IPMA. The trace elements studied seem to begood long-distance transport indicators, namely eruptive events, namely of eruptive events, since their concentration increases when tephras occur. On the other hand, in the lake records of Byers Peninsula they have not reported clear climatic signals, as they have not translated a behaviour that allows translating climatic phenomena. The C / N ratio is, however, a good climatic indicator showing a growth trend, meeting the trend of temperature increase in the peninsula. Sediments samples provide better conditions to study long distance transport and climate phenomena as they are a result of long term deposition and this way provide higher concentration increments, when compared to water samples. }
{pt=Antártida;Byers;ElTraço;Tefra;Sedimento, en=Antarctica;Byers;TraceEl.;Tephra;Sediment}

Dezembro 9, 2016, 14:0

Orientação

ORIENTADOR

João Alfredo Vieira Canário

CQE

Professor Auxiliar Convidado

ORIENTADOR

Marc Oliva Franganillo

Especialista