Rising sea levels threaten East Coast - Reuters

[Eugene]

Source: Reuters

Rising sea levels threaten East Coast
Fri Jan 16, 2009 6:18pm EST

By Jasmin Melvin

WASHINGTON (Reuters) - Sea levels on the United
States' mid-Atlantic coast are rising faster than the
global average because of global warming, threatening
the future of coastal communities, the Environmental
Protection Agency said on Friday.

Coastal waters from New York to North Carolina have
crept up by an average of 2.4 to 4.4 millimeters (0.09
to 0.17 inches) a year, compared with an average global
increase of 1.7 millimeters (0.07 inches) a year, the
EPA said in a report.

As a result, sea levels along the East Coast rose about
]a foot over the past century, the EPA's report,
commissioned by the Climate Change Science Program,
said.

The EPA focused on the mid-Atlantic region because it
"will likely see the greatest impacts due to rising
waters, coastal storms, and a high concentration of
population along the coastline," the agency said.

-snip-

Read more: http://www.reuters.com/article/environmentNews/idUSTRE50F6ZJ20090116

[LARED]

1. Perhaps this is a dumb question

but how does sea levels rise differently along the Eastern coast?

[RC]

2. How The Moon Affects Ocean Tides...

http://home.hiwaay.net/~krcool/Astro/moon/moontides/

# Offshore, in the deep ocean, the difference in tides is usually less than 1.6 feet

# The surf grows when it approaches a beach, and the tide increases. In bays and estuaries, this effect is amplified. (In the Bay of Fundy, tides have a range of 44.6 ft.)

# The highest tides in the world are at the Bay of Fundy in Nova Scotia, Canada.

# Because the earth rotates on its axis the moon completes one orbit in our sky every 25 hours (Not to be confused with moon's 27 day orbit around the earth), we get two tidal peaks as well as two tidal troughs. These events are separated by about 12 hours.


Basically it's the earths rotation and the timing of the moon effecting our oceans and is pulling the water from east to west. So the tides on the east coast are higher compaired to those on the west coast.

The higher ocean levels are cause by the ice caps melting.

[LARED]

3. I should have been more clear

I understand how the moon cause tides.

What I don't understand is how higher sea levels from melting ice caps preferentially rise along the Northern East coast.

[RC]

4. Melting ice caps cause rising sea's all over, but

"Basically it's the earths rotation and the timing of the moon effecting our oceans and is pulling the water from east to west. So the tides on the east coast are higher compaired to those on the west coast."

[Dogmudgeon]

5. It has been easier to measure on the East coast

I'm pretty sure that the continental shelf "slope" is so shallow that a few millimeters of vertical change can translate to several feet of horizontal change. Perhaps one of the geologists who post here from time to time can confirm (or correct) that.

But be assured that the water is rising world-wide. It isn't quite as dramatic elsewhere, but there are some places that are now uninhabitable, like parts of Tuvalu.

Then, too, as water warms up, it expands. It's just a small change, but every little bit counts.

There also may be new isostatic changes happening; this is where the shape of the globe changes due to changes in ice mass. There is actually detectable isostatic "rebound" still taking place from the end of the recent ice age, and there is probably at least a little more from recent loss of continental ice. This is a quickly-changing field and the details seem to change every month with each now batch of studies that are published.

--p!

[oldhippie]

6. It's due to the earth's gravity not being uniform .......

What you thinks of as "sea level" is not the same all over the world. Due to concentrations of the earth's mass, there are actually hills, valleys, and mountain on the surface of the seas. Do a google search on "lumpy gravity" or "geoid" and you'll see what I mean.

[OKIsItJustMe]

7. Check out the report

http://climatescience.gov/Library/sap/sap4-1/final-report/default.htm
http://www.epa.gov/climatechange/effects/coastal/sap4-1.html

Emphasis added by me:
http://yosemite.epa.gov/opa/admpress.nsf/0/ACC097A034222A7E852575400053055C

EPA Releases Report on Sea Level Rise

Release date: 01/16/2009

Contact Information: Roxanne Smith 202-564-4355 / [e-mail]; En español: Lina Younes 202-564-4355 / [e-mail]

(Washington, D.C. – Jan. 16, 2009) The U.S. Environmental Protection Agency, in collaboration with other agencies, has released a report that discusses the impacts of sea level rise on the coast, coastal communities, and the habitats and species that depend on them. The report, Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region, examines multiple opportunities for governments and coastal communities to plan for and adapt to rising sea levels.

Sea-level rise can affect coastal communities and habitats in a variety of different ways, including submerging low-lying lands, eroding beaches, converting wetlands to open water, intensifying coastal flooding, and increasing the salinity of estuaries and freshwater aquifers. It is caused by a number of natural and human-induced factors and can vary by region. Some impacts of sea-level rise can already be observed along the U.S. coast.

The primary causes of global sea-level rise are the expansion of ocean water due to warming and the melting of glaciers and ice sheets. Locally, sea-level rise is also influenced by changes to the geology of coastal land, making coastal elevation mapping an important area of future study. The Mid-Atlantic region, the focus of this report, is one of the areas in the U.S. that will likely see the greatest impacts due to rising waters, coastal storms, and a high concentration of population along the coastline.

EPA led the development of the report with significant contributions from the National Oceanic and Atmospheric Administration and the U.S. Geological Survey.

The report is one of 21 climate change synthesis and assessment products commissioned by the U.S. Climate Change Science Program (CCSP). CCSP was established in 2002 to provide the U.S. with science-based knowledge to manage the risks and opportunities of change in the climate and related environmental systems. The program is responsible for coordinating and integrating the research of 13 federal agencies on climate and global change.

More information on the report: http://www.epa.gov/climatechange/effects/coastal/sap4-1.html

Information on the U.S. Climate Change Science Program (CCSP): http://www.climatescience.gov/