From: Jeff Donnelly [[email protected]] Sent: Friday, April 28, 2006 4:55 PM To: [email protected] Subject: Re: Martha's Vineyard and Hurricanes

Hi Paul...

The current hospital location is relatively safe from hurricanes making to the west of Martha's Vineyard. For example from the 1938 hurricane at that location was between 4 and 6 feet. The location is much more susceptible to nor'easters. You might get 6 feet of surge associated with an intense nor'easter potentially with some large waves on top of that. However, my biggest concern is if an intense hurricane were to slowly pass to the east of the island. This would result in strong north and northeast winds that could pile significant storm surge and waves into Vineyard Haven Harbor. The October 3, 1841 hurricane was just such a storm. One of the key factors is the forward motion of the storm. If the storm track is to the east of the island and it is moving rapidly the speed of forward motion would be subtracted from the rotary winds of the west side of the storm and the duration of strong winds would be less (a couple of hours or less). If the storm moves slowly the duration of onshore hurricane force winds could be more like 6 to 10 hours. In this scenario the hospital might be in peril. You could get between 10 and 15 feet of storm surge in Vineyard Haven Harbor during such an event. From my read of the topographic map it looks like the hospital is between 10 and 20 feet above sea level. Do you know the exact elevation of the hospital? Does it have multiple floors?

Over the past 200 years this kind of event (intense hurricane passing just east of MV) has been relatively rare. With the 1841 storm being the prime example. A similar storm (though likely less intense) passed just east of in August of 1924. Had a terribly slow moving not taken an abrupt right turn before arriving in Martha's Vineyard in September, 1961, it could have been a near worst case scenario.

Hope this helps. Let me know if you need any additional information.

Cheers,

Jeff

------Jeffrey P. Donnelly Coastal Systems Group Geology and Geophysics Department, MS22 Woods Hole Oceanographic Institution Woods Hole, MA 02543 tel. 508-289-2994 fax 508-457-2187 ------