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Boothbay Me Unusual Tide Changes
"Alisdair Gurney" wrote in
: Damage is worse than any storm in memory. Since it's my former hometown, it is especially interesting. Local sources do not indicate any seismic activity but there may simply be a lag in reporting. A similar but smaller surge was reported in Cundys Harbor. Both places are similar in having configurations that could magnify surge effects and also in that both are more active at this time of year than other nearby areas where surge might simply not have been observed. It's got tsunami written all over it. There IS a history: http://www.state.me.us/doc/nrimc/mgs...nami/jan05.htm If it happened on 10/28/08 at 3PM mentioned in the article, I don't see any USGS Atlantic activity near that date/time or hours before, in the Atlantic, other than several strength 2-4 quakes in a cluster along the S side of the trench N or Puerto Rico where the 5.5 quake happened today. There was a 5.5 underwater quake on the south side of the trench, in a cluster of quakes over the last day or so just N of Puerto Rico, but the times are all wrong. NWS report is more accurate: "PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE GRAY ME 630 PM EST WED OCT 29 2008 ....TUESDAY'S UNUSUAL TIDE FLUCTUATIONS ALONG THE MID-MAINE COAST... THE CAUSE OF YESTERDAY'S UNUSUAL TIDE FLUCTUATIONS ALONG THE MID COAST OF MAINE REMAINS A MYSTERY...AND MAY NEVER BE KNOWN. SIGNIFICANT RAPID RISES AND FALLS IN TIDE LEVELS WERE OBSERVED AROUND 3 PM IN BOOTHBAY HARBOR, SOUTHPORT, AND BRISTOL. ONLY VERY MINOR FLUCTUATIONS WERE NOTED AT TIDE GAUGES ALONG THE COAST. THERE ARE SEVERAL POSSIBLE EXPLANATIONS FOR YESTERDAY'S EVENT. RAPID SURGES CAN BE CAUSED BY THE UNDERWATER MOVEMENT OF LAND, MOST OFTEN DUE TO AN EARTHQUAKE, OR DUE TO THE SLUMPING OF SEDIMENTS ALONG A STEEP CANYON OR SHELF. NO EARTHQUAKES WERE REPORTED IN THE AREA YESTERDAY. IN RARE INSTANCES, LARGE AND RAPID SURGES CAN BE GENERATED BY STORMS. IN EITHER CASE, THE BATHYMETRY OF THE OCEAN FLOOR REFLECTS AND REFRACTS THE WAVE ENERGY AND CAN CAUSES SIGNIFICANT VARIATIONS IN TIDE LEVELS ALONG THE COAST...AND RAPID CHANGES IN TIDE LEVELS AT A PARTICULAR LOCATION. THESE SURGES ARE QUITE UNLIKE THE MUCH SLOWER SURGES NORMALLY ASSOCIATED WITH COASTAL STORMS. EYE-WITNESS REPORTS FROM SEVERAL LOCATIONS INDICATED THAT WATER LEVELS FELL AND ROSE FROM 4 FEET TO AS MUCH AS 12 FEET ALONG THE COAST DURING THE EVENT. THESE RAPID CHANGES IN TIDAL LEVELS GENERATED THE STRONG CURRENTS THAT DAMAGED PIERS AND BOATS IN THE AREA. ALTHOUGH THESE EVENTS ARE RARE ALONG THE MAINE COAST, THEY HAVE OCCURRED IN THE PAST. ON JANUARY 9, 1926, AN EVENT SIMILAR TO YESTERDAY'S EVENT WAS OBSERVED IN BASS HARBOR. DURING THAT EVENT, THE HARBOR DRAINED RAPIDLY AND THEN WAS FOLLOWED BY A 10 FT SURGE OF WATER, FOLLOWED BY TWO OTHER SMALLER WAVES. THERE WERE NO EARTHQUAKES REPORTED ON THAT DAY. NO ONE WAS INJURED IN THAT EVENT BUT ABOUT 50 FISHING BOATS WERE HURLED ASHORE. $$ JENSENIUS NATIONAL WEATHER SERVICE GRAY, MAINE NNNN" I found some good discussions with supporting maps and references on this topic in this discussion group: http://able2know.org/topic/124844-1 We who live so near the sea, do so in our peril in many more ways than we envision...... |
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