Past and future sea level change Q2 Flashcards
how is ecological data used to determine past sea level rise trends?
indicator species in the fossil record can provide valuable data for reconstructing past sea levels. U-series methods can be used to determine biological, geomorphological, sedimentological, and chemical features that provide information on the position of the sea surface at the time that they lived or were formed.
what are two examples of ecological indicators used to measure sea level?
Fossil corals - Hibbert et al (2016)
Beach-rock exposure provide a record of Holocene sea-level rise in Brazil (Irion et al, 2011)
why are corals a good indicator of sea level rise?
Many corals are good indicators of past sea levels because they only grow in shallow water. If the sea rises, new coral grows on top of the old, forming terraces that track the change in sea level.
what are the disadvantages of using ecological data to determine sea level rise?
the distribution of marine species are influenced by many biotic and abiotic factors therefore we cannot assume that sea level is the only influence of past distribution
fossil bones, teeth, and shell, are often inherently unsuitable for U-series dating because these organic materials are subject to postmortem open-system behavior and may suffer contamination (Pickering, 2016)
how is archaeological data related to sea level rise?
Archaeologists study sites that are close to the sea’s shorelines as well as those that have already disappeared below the waves, collecting information on past sea levels
what is an example of archaeological data used to determine sea level?
the North Sea Palaeolandscapes
Project analysed 2D and 3D
seismic records made available by oil companies operating in the North Sea which found details about the now-submerged Holocene land surface (Bailey and Cawthra, 2021)
what are the limitations of using archaeological data?
shorelines are generally exposed to the potentially destructive impact
of surf action and turbulent water currents during the
initial stage of inundation by sea-level rise. It is, therefore, easy to assume that most archaeological evidence and
much of the physical evidence of the surrounding landscape associated with submerged shorelines would have been
disturbed, destroyed, or buried out of sight under marine sediments.
Burial beneath marine sediment
removes the archaeological evidence from view, and it can only be discovered if the buried material is exposed
subsequently by erosion, either by natural processes or
by human activities such as trawler fishing or engineering
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