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Introduo Cincia do Sistema Terrestre
Segunda Lista de Exerccios
Questo 1
Oscilaes milenares e mudanas abruptas no paleo-ambiente do
Sistema Terrestre. A figura abaixo do livro texto indica
registrospaleoclimticos na escala milenar para dois stios de
pesquisa, indicandooscilaes na escala milenar e mudanas abruptas.
Estude a figura, consultebibliografia especializada de modo a
entender to completamente quantopossvel os dados apresentados. Suas
respostas devem ser feitas num textoentre 1,5 e 3 pginas, com
referncias e um glossrio de todos os termostcnicos.
Fig. 2.6. Milennial scale oscillations and abrupt changes
Low latitude expression of millennia scale climate oscillations
taken fromGISP2 oxygen isotopes, Santa Barbara basin (Site 893)
bioturbation index andhigh-frequency variations in the CaC03 record
of 70KL (Behl and Kennett
1996). Comparison of site 893 bioturbation index and benthic
foraminiferal6180 records with 6180 ice time series from GISP2,
showing the excellentcorrelation of site 893 anoxia (lamination)
events to 16 of 17 of the warminterstadials of GISP2. Bioturbation
index is presented as a 49 cm (ca. 300-400 years) running average
to dampen high-frequency variation and to matchthe resolution of
the GISP2 record. Chronologies for GISP2 and site 893
wereindependently derived. Radiocarbon age control points (+) and
SPECMAP dataused for the site 893 age model are shown to the right.
Numbers in 0 refer tostandard data of the SPECMAP stratigraphy. The
base of each core interval inHole 893A is indicated by arrows to
the left (Behl RJ, Kennett JP (1996) Brief
interstadial events in the Santa Barbara Basin, NE Pacific,
during the past 60kyr. Nature 379: 243-24
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Questo 2
Acidificao dos Oceanos. Com base no material includo a seguir e
emoutros materiais sobre o assunto que voc pode consultar, o que
vocentende pelo processo chamado de acidificao dos oceanos. Escreva
umtexto entre 1,5 e 3 pginas.
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Acidificao dos Oceanos
(Feely et al., 2008)
*
Acidificao dos Oceanos
pH = 7.8 aragonita no se forma
ameaa 40% dos organismos
marinhos de estrutura ssea
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CO2absorption by the oceans
Carbon dioxide is less soluble in warmer water
Rising sea temperatures bring about less CO2absorption
Positive feedback in abrupt transitions fromglacial to
interglacial periods
2.3.2 BiogeochemicalProcesses
CO2absorption by the oceans
Carbon dioxide is less soluble in warmer water
Rising sea temperatures bring about less CO2absorption
Positive feedback in abrupt transitions fromglacial to
interglacial periods
2.3.2 BiogeochemicalProcesses
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Vilcinskas 2000
Surface Ocean pH decreases with withincreasing atmospheric
CO2:
Solas Science and Implemantation Plan
Time series of average surface [CO3-2] in
the Southern Ocean for the PIUB-Bernreduced complexity model
(Orr et al,Nature, 2005)
2.3.2 BiogeochemicalProcesses
From R. Buddemeier, based on Kleypas et al. 1999
2.3.2 BiogeochemicalProcesses
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From R. Buddemeier, based on Kleypas et al. 1999
2.3.2 BiogeochemicalProcesses
From R. Buddemeier, based on Kleypas et al. 1999
2.3.2 BiogeochemicalProcesses
Questo 3
Estados mltiplos de equilbrio entre vegetao e clima.
Possivelmente, o melhor exemplo da importncia da vegetao como
fatorformador do clima pode ser derivado da mudana abrupta de
vegetao noNorte da frica, de savana para deserto, no mdio Holoceno.
Explique quetipo de interao entre a superfcie vegetada e a
atmosfera possa ter ocorrido
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que possa explicar o carter abrupto da mudana de vegetao (texto
entre1,5 e 3 pginas).
Source:Steffen at al., 2004. Global Change and the Earth System.
A planet under preassure. IGBP Book Series. Springer VerlagChapter
2: Planetary Machinery: The dynamics of the earth system prior to
significant human influence pg. 69.
Fig. 2.60.The abrupt change fromsavanna to desert in North
Africa duringthe mid-Holocene: a change in theregional flux of
solar radiation at Earth'ssurface due to a small change in
theEarth's orbit; b simulated change inrainfall ultimately
triggered by thechange in incident solar radiation; cchange in
fraction vegetation cover inresponse to changing rainfall; and
dmodel predictions(solid line)andobservations(broken line)of
theresulting increase in wind erosion and
deposition of sand off the West Africancoast (Claussen et al.
1999; deMenocalet al. 2000)
Springer
-VelargBerlinHeidelberg2005
