Sea-level and deep-sea-temperature variability over the past 5.3 million years

Nature ◽  
2014 ◽  
Vol 508 (7497) ◽  
pp. 477-482 ◽  
Author(s):  
E. J. Rohling ◽  
G. L. Foster ◽  
K. M. Grant ◽  
G. Marino ◽  
A. P. Roberts ◽  
...  
Keyword(s):  
Sea Level ◽  
Deep Sea ◽  
Temperature Variability ◽  
Sea Temperature ◽  
The Past

scholarly journals Erratum: Corrigendum: Sea-level and deep-sea-temperature variability over the past 5.3 million years

Nature ◽  
2014 ◽  
Vol 510 (7505) ◽  
pp. 432-432 ◽  
Author(s):  
E. J. Rohling ◽  
G. L. Foster ◽  
K. M. Grant ◽  
G. Marino ◽  
A. P. Roberts ◽  
...  
Keyword(s):  
Sea Level ◽  
Deep Sea ◽  
Temperature Variability ◽  
Sea Temperature ◽  
The Past

scholarly journals Sea level and deep-sea temperature reconstructions suggest quasi-stable states and critical transitions over the past 40 million years

2021 ◽  
Vol 7 (26) ◽  
pp. eabf5326
Author(s):  
Eelco J. Rohling ◽  
Jimin Yu ◽  
David Heslop ◽  
Gavin L. Foster ◽  
Bradley Opdyke ◽  
...  
Keyword(s):  
Sea Level ◽  
Deep Sea ◽  
Dynamical Behavior ◽  
Linear Scaling ◽  
Sea Level Changes ◽  
Stable States ◽  
Sea Temperature ◽  
Ice Volume ◽  
The Past ◽  
Critical Transitions

Sea level and deep-sea temperature variations are key indicators of global climate changes. For continuous records over millions of years, deep-sea carbonate microfossil–based δ18O (δc) records are indispensable because they reflect changes in both deep-sea temperature and seawater δ18O (δw); the latter are related to ice volume and, thus, to sea level changes. Deep-sea temperature is usually resolved using elemental ratios in the same benthic microfossil shells used for δc, with linear scaling of residual δw to sea level changes. Uncertainties are large and the linear-scaling assumption remains untested. Here, we present a new process-based approach to assess relationships between changes in sea level, mean ice sheet δ18O, and both deep-sea δw and temperature and find distinct nonlinearity between sea level and δw changes. Application to δc records over the past 40 million years suggests that Earth’s climate system has complex dynamical behavior, with threshold-like adjustments (critical transitions) that separate quasi-stable deep-sea temperature and ice-volume states.

scholarly journals The response of a simple Antarctic ice-flow model to temperature and sea-level fluctuations over the Cenozoic era

2007 ◽  
Vol 46 ◽  
pp. 69-77 ◽  
Author(s):  
C.I. Van Tuyll ◽  
R.S.W. Van De Wal ◽  
J. Oerlemans
Keyword(s):  
Sea Level ◽  
Deep Sea ◽  
Flow Model ◽  
Ice Sheet ◽  
Temperature Record ◽  
Ice Flow ◽  
Antarctic Ice Sheet ◽  
Sea Temperature ◽  
Ice Volume ◽  
The Antarctic

AbstractAn ice-flow model is used to simulate the Antarctic ice-sheet volume and deep-sea temperature record during Cenozoic times. We used a vertically integrated axisymmetric ice-sheet model, including bedrock adjustment. In order to overcome strong numerical hysteresis effects during climate change, the model is solved on a stretching grid. The Cenozoic reconstruction of the Antarctic ice sheet is accomplished by splitting the global oxygen isotope record derived from benthic foraminifera into an ice-volume and a deep-sea temperature component. The model is tuned to reconstruct the initiation of a large ice sheet of continental size at 34 Ma. The resulting ice volume curve shows that small ice caps (<107 km3) could have existed during Paleocene and Eocene times. Fluctuations during the Miocene are large, indicating a retreat back from the coast and a vanishing ice flux across the grounding line, but with ice volumes still up to 60% of the present-day volume. The resulting deep-sea temperature curve shows similarities with the paleotemperature curve derived from Mg/Ca in benthic calcite from 25 Ma till the present, which supports the idea that the ice volume is well reproduced for this period. Before 34 Ma, the reproduced deep-sea temperature is slightly higher than is generally assumed. Global sea-level change turns out to be of minor importance when considering the Cenozoic evolution of the ice sheet until 5 Ma.

Late Pleistocene Sea level on the New Jersey Margin: Implications to eustasy and deep-sea temperature

2009 ◽  
Vol 66 (1-2) ◽  
pp. 93-99 ◽  
Author(s):  
James D. Wright ◽  
Robert E. Sheridan ◽  
Kenneth G. Miller ◽  
Jane Uptegrove ◽  
Benjamin S. Cramer ◽  
...  
Keyword(s):  
New Jersey ◽  
Sea Level ◽  
Late Pleistocene ◽  
Deep Sea ◽  
Sea Temperature

Quaternary Hypsithermals

1972 ◽  
Vol 2 (3) ◽  
pp. 270-273 ◽  
Author(s):  
Cesare Emiliani
Keyword(s):  
High Temperature ◽  
Deep Sea ◽  
Isotopic Analysis ◽  
The Past ◽  
Absolute Dating ◽  
Oxygen Isotopic ◽  
Environmental Balance ◽  
Past Half ◽  
Oxygen Isotopic Analysis

Oxygen isotopic analysis and absolute dating of deep-sea cores show that temperatures as high as those of today occurred for only about 10% of the time during the past half million years. The shortness of the high temperature intervals (“hypsithermals”) suggests a precarious environmental balance, a condition which makes man's interference with the environment during the present hypsithermal extremely critical. This precarious balance must be stabilized if a new glaciation or total deglaciation is to be avoided.

Salt marshes adjustment to anthropogenic pressures and sea-level rise

2021 ◽  
Author(s):  
A. Rita Carrasco ◽  
Katerina Kombiadou ◽  
Miguel Amado
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Salt Marshes ◽  
Anthropogenic Pressures ◽  
The Past ◽  
Ria Formosa ◽  
Sediment Loads ◽  
Human Interventions ◽  
South Portugal ◽  
And Sea Level

&lt;p&gt;It is predictable that salt marshes in regions, where sediment loads are high, should be stable against a broader range of relative sea level scenarios than those in sediment-poor systems. Despite extensive theoretical and laboratory studies, additional syntheses of marsh &amp;#8216;persistence&amp;#8217; indicators under human interventions and accelerated sea-level rise rates are still needed. This study investigates the recent lateral changes occurring in lagoon-type marshes of the Ria Formosa lagoon (south Portugal) in the presence of human interventions and sea-level rise, to identify the major drivers for past marsh evolution and to estimate potential future trends. The conducted analysis assessed the past geomorphological adjustment based on imagery analysis and assessed its potential future adjustment to sea-level rise (~100 years) based on modelled land cover changes (by employing the SLAMM model within two sea-level rise scenarios).&lt;/p&gt;&lt;p&gt;Salt marshes in the Ria Formosa showed slow lateral growth rates over the last 70 years (&lt;1 mm&amp;#8729;yr&lt;sup&gt;-1&lt;/sup&gt;), with localized erosion along the main navigable channels associated with dredging activities. Higher change rates were noted near the inlets, with stronger progradation near the natural inlets of the system, fed by sediment influx pulses. Any potential influence of sea-level increase to an intensification of marsh-edge erosion in the past, could not be distinguished from human-induced pressures in the area. No significant sediment was exchanged between the salt marshes and tidal flats, and no self-organization pattern between them was observed in past. The related analysis showed that landcover changes in the salt marsh areas are likely to be more prominent in the future. The obtained results showed evidence of non-linearity in marsh response to high sea-level rise rates, which could indicate to the presence of critical thresholds and potential negative feedbacks within the system, with significant implications to marsh resilience.&lt;/p&gt;

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