the last 150,000 years of sea levels–3 graphs

1998.  Existing techniques for estimating natural fluctuations of sea level and global ice-volume from the recent geological past exploit fossil coral-reef terraces or oxygen-isotope records from benthic foraminifera. Fossil reefs reveal the magnitude of sea-level peaks (highstands) of the past million years, but fail to produce significant values for minima (lowstands) before the Last Glacial Maximum (LGM) about 20,000 years ago, a time at which sea level was about 120 m lower than it is today1, 2, 3, 4. The isotope method provides a continuous sea-level record for the past 140,000 years (ref. 5) (calibrated with fossil-reef data6), but the realistic uncertainty in the sea-level estimates is around plusminus20 m. Here we present improved lowstand estimates—extending the record back to 500,000 years before present—using an independent method based on combining evidence of extreme high-salinity conditions in the glacial Red Sea with a simple hydraulic control model of water flow through the Strait of Bab-el-Mandab, which links the Red Sea to the open ocean. We find that the world can glaciate more intensely than during the LGM by up to an additional 20-m lowering of global sea-level. Such a 20-m difference is equivalent to a change in global ice-volume of the order of today’s Greenland and West Antarctic ice-sheets.  http://www.nature.com/nature/journal/v394/n6689/full/394162a0.html

……………………………………………………………………………………………………………………

graph not dated.

http://www.freerepublic.com/focus/news/1671134/posts?q=1&;page=151

…………………………………………………………………………………………………………………..

2014 Red Sea.

(a) Red Sea RSL data (blue) for 0–150 kyr (ref. 5) and 150–500 kyr (this study), superimposed on the 95% probability interval of the RSL dataset (light grey) and 95% probability interval for the probability maximum (dark grey).     http://www.nature.com/ncomms/2014/140925/ncomms6076/abs/ncomms6076.html

……………………………………………………………………………………..

2014.

drownedreef_sealevel_s

Figure 3. Sea-level for the past 500,000 years   http://deepreef.org/projects/36-deep-osprey-reef.html
…………………………………………………………………………………………………………..

decided that 150,000 years ago to present is most useful period, simplifying the complexities. using sea levels graphed helps one to avoid endless left-brain details/arguments and go toward a reasonable overview; i think that the heat/cold dynamic on the Earth must travel through the quite-unified seas and therefore can be reasonably measured there in a fell swoop for a point of time. how many complications tend to develop because people are already scattered across 50 to 10,000 various angles on things?

the idea overall here is that we need a fundamental in-common reference picture or backdrop to reasonably discuss and investigate the subject of heat flow on the Earth “surface”.  i do not see why the 150,000 years to present sea level graphics miss at all the fundamental reference picture; but if there be a better one that is extant, what is it?   -R, Mt. Shasta, CA

Leave a comment