Posted on 08/01/2015 12:48:19 PM PDT by VinL
All the political gridlock in Congress and name-calling during election season may not matter as much when Washington, D.C. sinks into the ocean.
According to new research conducted by geologists at the University of Vermont and the U.S. Geological Survey, the land in the Chesapeake Bay region, including the nation’s capital, is sinking rapidly. The sea level in the Chesapeake is rising at twice the global average and faster than anywhere else on the East Coast, the researchers say, which means D.C. will sink 6 or more inches in the next 100 years.
The sinking is caused by melting ice sheets which caused underlying rock to bulge upward. As the ice melts, the rock bulge drops. Scientists say this will cause more flooding in the region, which is already getting worse from global warming.
“Right now is the time to start making preparations,” said Ben DeJong, lead author of the study, in a University of Vermont press release. “Six extra inches of water really matters in this part of the world.”
(Excerpt) Read more at time.com ...
Ignore the slanted Time article (which wrongly makes the problem of a sinking shoreline seem like it is tied to current global warming) and click this link (embedded in the Time article)(http://www.geosociety.org/gsatoday/archive/25/8/article/i1052-5173-25-8-4.htm) for the actual Geological Society of America (GSA) article.
From the GSA article summary:
“Data indicate that the region was submerged at least for portions of marine isotope stage (MIS) 3 (ca. 60–30 ka), although multiple proxies suggest that global sea level was 40–80 m lower than present. Today MIS 3 deposits are above sea level because they were raised by the Last Glacial Maximum forebulge, but decay of that same forebulge is causing ongoing subsidence. These results suggest that glacio-isostasy controlled relative sea level in the mid-Atlantic region for tens of thousands of years following retreat of the Laurentide Ice Sheet and continues to influence relative sea level in the region. Thus, isostatically driven subsidence of the Chesapeake Bay region will continue for millennia, exacerbating the effects of global sea-level rise and impacting the region’s large population centers and valuable coastal natural resources.”
The last paragraph of the GSA article:
“For Washington D.C. and other coastal cities, risk assessment and adaptation planning based on the full range of possible RSL rise scenarios is critical. The analysis by Ayyub et al. (2012) indicates significant losses for Washington D.C. with a rise of 0.4 m, well below the minimum predicted rise of sea level for AD 2100 of 0.49–0.98 m. This analysis under-predicts the most likely RSL rise over the next century, in part because it does not explicitly consider that GIA will drive increased RSL independent of climate change. We conclude that risk assessments and adaptation planning for sea-level rise should consider the full range of sea-level estimates (e.g., Miller et al., 2013) and take local subsidence values into consideration, particularly for high-density population centers like Washington D.C.”
In layman’s terms, the land surface south of the maximum expansion of the continental ice sheets during the last Ice Age was pressed upward by the weigh of all the ice to the north (forebulge) and since the removal of that weight at the end of the Ice Age, the bulged upward land is subsiding (approximately 1.3–1.7 mm/yr). The good news (for those worried about it) is that the forebulge is localized and, as the following except from the Discussion portion of the article implies, does not affect the Atlantic seaboard south of North Carolina:
“The presence of MIS 3 estuarine deposits near today’s sea level confirms the effects of GIA over long timescales for the Blackwater National Wildlife Refuge and supports similar interpretations within the greater Chesapeake Bay region. The elevations of MIS 3 estuarine deposits generally decrease from the Central Delmarva Peninsula southward to North Carolina (Scott et al., 2010); dated, emerged MIS 3 estuarine deposits are not found south of North Carolina. While the maximum elevations of MIS 3 deposits vary (GSA Supplemental Data Fig. S8 [see footnote 1]), decreasing elevations to the south are consistent with the shape of the forebulge based on subsidence rates (Engelhart et al., 2009). High-precision GPS data, though limited to a short time series, also indicate the highest rates of subsidence on the Atlantic coast are centered on the Chesapeake Bay region (Sella et al., 2007; Snay et al., 2007).”
Not fast enough.
Time really fouled up this story. The entire Chesapeake basin was pushed up by glaciers north of it — during the LAST ICE AGE. When the glaciers retreated about 12 to 22,000 years ago, the basin began to settle. It’s still settling and will continue to do so until the glaciers return.
These guys aren't worth it.
Build regular office buildings. All that ‘grandeur’ goes to their heads and they forget it's A JOB - they're NOT royalty - in spite of what the toadies and lobbyist tell them. It's just a job.
They need to DO THE JOB THEY WERE SENT TO DO... SECURE THE BORDERS. STOP ANCHOR BABIES. KEEP THE COUNTRY SAFE. STOP GIVING OUR JOBS AWAY.
New York’s Adirondaks are still rebounding after 10,000 years.
True, so is a lot of the north, wherever the ice sheets were sufficiently thick. 10,000 years is a short time in geology. I don’t know whether or how the D.C. subsidence would be coupled to that. As I said, I don’t know enough about the tectonics of the Eastern Seaboard to draw conclusions either way, just that the article writer got the whole depression/rebound thing wrong.
Thanks for clicking through to the source and explaining the subsidence.
I just hope they don’t all run uphill to my suburb!
Can’t happen soon enough.
Maryland “Freak State” DANG!
The Washington Wetbacks ?
Periscopes down......
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