U.S. vulnerability to sea level rise
In the last century, sea level rose 5 - 6 inches (13 - 15 cm) more than the global average of 7 inches (18 cm) along the U.S. Mid-Atlantic and Gulf Coasts, because coastal lands there are sinking. Over 50% of the U.S. coastline is vulnerable or highly vulnerable to sea level rise, according to the Coastal Vulnerability Index (CVI) developed by the United States Geological Survey (USGS). In the U.S., relative sea level rise (the combined effects of global sea level rise plus the fact the land is sinking) is highest along the Mississippi River Delta in Louisiana, where relative sea level rises of 3.2 ft (.98 meters) have been observed during the 20th century. This is one of the highest relative sea level rises in the world. According to the NOAA Tides and Currents sea level rise interactive tool, the U.S. tide gauges that have shown the highest rates of sea level rise over the past century are at Grand Island, LA (1.8 ft rise since 1947), Galveston, TX (1.1 ft since 1957), and Chesapeake Bay, VA (0.6 feet since 1975). Alaska and some areas along the Pacific Northwest coast are at low risk of sea level rise, because the relative sea level is actually falling at present. Land in these regions is rising as it recovers from removal of the weight of the great ice sheets that covered much of North America during the last Ice Age. For example, relative sea level at Kodiak Island, Alaska has fallen by 1.1 feet since 1975, despite the fact global sea level has been increasing.
Figure 1. Twentieth century annual relative sea-level rise rates in mm/year along the U.S. coast. The higher rates for Louisiana (9.85 millimeters [mm] per year, about 3.3 ft/century) and the mid-Atlantic region (1.75 to 4.42 mm per year, 0.6 - 1.4 ft/century) are due to land subsidence. Sea level is stable or dropping relative to the land in the Pacific Northwest, as indicated by the negative values, where the land is tectonically active or rebounding upward in response to the melting of ice sheets since the last Ice Age. Image credit: Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region (data from Zervas, 2001).
U.S. Coastal Vulnerability
The Coastal Vulnerability Index (CVI) takes into account six factors:
1) The geology of the coast. Barrier islands, river deltas, and marshes are the most vulnerable to erosion and sea level rise, while steep, rocky cliff shores are the least. Sheltered bays like Galveston Bay and Tampa Bay are less vulnerable than the exposed coasts. (Note, however, that hurricane storm surges are typically higher in sheltered bays, at least for slow-moving storms).
2) How steep the land near the coast is. Gently sloping lands are the most vulnerable. In the Gulf Coast region, the slope variable has the highest risk ranking along the Louisiana coast, the Texas coast north of Corpus Christi, and the southwest Florida coast.
3) The local rate of sea level rise. The sea level is rising faster along the western Gulf of Mexico than the eastern Gulf. The highest rates of sea-level rise in the Gulf of Mexico (and in the United States) are in the Mississippi delta region (10 mm/yr, or 1 inch/2.5 years).
4) The amount of shoreline erosion going on. Most of the U.S. coast is moderately or severely eroding, and very few areas are gaining (Figure 2).
5) The mean tidal range. Shores that have a large difference between low and high tide are less likely to get a significant storm tide--the height above mean sea level of the sum of the storm surge plus the tide. For example, in a region like Maine, which has a 12 ft range between low and high tide, a storm having a 9 ft storm surge will have a storm tide below local high tide for a quarter of a tidal cycle. Shores with a very narrow tidal range (e.g., the 2 ft tidal range common along the Texas and Louisiana Gulf Coast) will get a storm tide of 8 - 10 feet with the 9 ft storm surge in the above example. Shorelines with a narrow tidal range always get high storm tides regardless of when the storm surge hits.
6) How high the waves at shore are. Obviously, shores that experience higher wave heights are at greater risk. In the Gulf of Mexico, wave energy is highest along sections of the Texas coast and on the southern tip of the Mississippi delta.
Figure 2. Shoreline change around the United States based on surveys over the past century. All 30 coastal states are experiencing overall erosion due to natural processes (e.g., storms, sea-level rise) and human activity. If the shoreline is uncolored, no data was available. Image credit: USGS, 1985, and taken from Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region).
The Coastal Vulnerability Index (CVI) web page gives detailed maps of each section of the U.S. coast, along with specific reasons why each portion of the coast was assigned the ranking it got. A brief summary:
The Gulf Coast
The Gulf Coast has 55% of its length in the "very high" or "high" vulnerability range. Fully 41% of the coast falls in the "very high" range, far more than the 28% in that category along the Pacific coast and 23% along the Atlantic coast. The region around New Orleans is the most vulnerable region of the entire U.S. coast. The Florida Panhandle, as well as the West Florida coast, are at low to moderate risk because the land is not sinking much, wave heights are lower, and the slope of the land is relatively steep near the coast. The Texas coast is considered to be at a high to very high risk because of the relatively high mean wave height, sinking land, and shallow coastal slope.
The East Coast
The East Coast has 50% of its length in the "very high" or "high" vulnerability range. The highest vulnerability areas are typically high-energy coastlines where the regional coastal slope is low and where the major landform type is a barrier island. A significant exception to this is found in the lower Chesapeake Bay. Here, the low coastal slope, vulnerable landform type (salt marsh) and high rate of relative sea-level rise combine for a high CVI value. The coastline of northern New England, particularly Maine, shows a relatively low vulnerability to future sea-level rise. This is primarily due to the steep coastal slopes and rocky shoreline characteristic of the region, as well as the large tidal range.
The Pacific Coast
The Pacific Coast has 50% of its length in the "very high" or "high" vulnerability range. Areas of very high vulnerability include the San Francisco - Monterey Bay coast and in southern California from San Luis Obispo to San Diego, where the coast is most highly populated. The highest vulnerability areas are typically lower-lying beach areas. The low risk, least vulnerable areas generally occur at rocky headlands along cliffed coasts where the coastal slope is steep, relative sea-level is falling, tide range is large, and wave energy is lower. Examples of these areas are the northern coast of Washington, Monterey, and Cape Mendocino, California.
Figure 3. The Coast Vulnerability Index (CVI) for the U.S.
References
Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region.
National Assessment of Coastal Vulnerability to Sea-Level Rise: Preliminary Results for the U.S. Gulf of Mexico Coast (USGS, 2000).
Jeff Masters
Reader Comments
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Just kidding, futuremet.
And others: do NOT place a magnet near your harddrive unless you do no like your software or data.
Hehe... got to have the disclaimer... since there's always someone that actually does it and then ask why they can't get into their OS anymore. :P
Current temperature here in PR
82 F
88 F Heat Index
And is really Hot so I can't imagine what a 100 F feels!
I really miss the low 70 F that we get most of the tropical winter.
Ensure you understand any applicable copyright laws if considering this item.
Part of their website says it converts the video to the mp3, and some of it says the audio. So does it extract both the video and
the audio, or just the audio to listen to?
MP3's are audio only, you are talking about MP4's
oops thats what I meant, thanks!
Just for the record, it would take a very, very strong magnet to wipe a drive. It is mostly a very strong magnet itself.
If you purposely want to destroy one, use a sledge hammer repeatedly before disposal. Don't count on a magnet doing the job it probably will not do it.
Never toss out any hard drive until you completely destroy it.
Launch window: 2214-2314 GMT (6:14-7:14 p.m. EDT)
Spaceflightnow
50kt shear no chance.
Stillwaiting, did ya get any of that nasty storm last night?
Is the blob going to regenerate, looking at the GOM the trough is stil there it just looks like the blob thinned out...is there any LLC
Yea. We are going to be looking at a late start season. I think we may have to wait till the late July or even early August.
ATLANTIC BASIN
AOI
10N/10W
AOI
11N/56W
I think those Eward moving troughs will have 2 cool it before we see anything serious.
This is the set-up for our trough-split that is beginning now and will complete within 48 hours. The frontal trough and associated area of weak low pressure near the NE gulf coast are going to be sitting in the same area for a few days as the upper flow gets split and an upper feature starts backing to the SW. Situations like this always, always have to be watched for mischief no matter what, as the convergence caused by the surface trough combined with the upper feature can cause cyclogenesis. In 3-4 days energy from the tropical wave that will be moving into the NW Caribbean will get piled into the area as well.
There may be nothing on the models right now, but they rarely pick-up on home-brew developments until they're right on top of them. What they are showing is the moisture that will be lingering in the area over the next several days, and this area should be watched. Troughs in the Gulf of Mexico always mean trouble when they start sitting around, even if nothing substantial organizes.
TUTT lifts out in 4-6 days. The upper-level environment will be marginal.
LOL
It almost looks like winter.
lol
...BUT...EARLY IN THE CYCLE...A LOW IS TO FORM JUST NORTH OF WESTERN CUBA OVER THE GULF OF MEXICO...WITH CLOSED CIRCULATION TO DRIFT SOUTHWEST TO THE NORTHERN YUCATAN THROUGH 48 HRS...AND MEANDER OVER THE CAMPECHE SOUND BY 72 HRS.
Well south of about 32N it ceases to be a true front, and is only a trough from then on. There is no big differences in temperature on either side of the front since the low-pressure system has been sitting there for so long and weakened considerably. The moisture in your image is basically bounding the upper trough, and it's not unusual to see them that far south at this time of year. That's why trough-splits are a problem in the early and late hurricane season.
He got my attention. Who dat blob gonna be ?
Native New Orleans girl now living in Florida panhandle ... wondering where dat blob gonna go ?
Well first we need a blob lol. I'm only mentioning the possibility of troublesome stuff stirring up in the GOM over the next few days. However most features will be drifting slowly generally towards the SW away from the north gulf coast.
True but it's not that unusual when you consider that the pattern is very amplified right now with a negative NAO and AO. Lots of north-south movement of the air instead of west-east.
It was kickin here. I would bet we had 60-70mph winds min. It moved my portable, 400 lb B-ball hoop and tossed everything in the yard around. I am one exit north and power was out but not sure how long. I was watching the backs of my eyelids :)
No, the one the GFS develops is still over Africa at around 5W.
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