Written by the TreasureGuide for the exclusive use of treasurebeachesreport.blogspot.com.
After all of the big surf the past few days, there was more accretion than erosion along the Treasure Coast. I talked about a couple of the reasons for that yesterday. I mentioned the amount of sand in front of the beach that was absorbing most of the wave energy before the waves hit the beach, along with the angle of the waves.
You've probably heard of the legendary Thanksgiving Storm or 1984. I've mentioned it several times before and I posted the exciting story of one person that was there that day. I also posted a NOAA report that explained why that storm damaged the beaches so much. While people are wondering what happened and why the recent waves didn't do much for us, I thought it would be a good time to post some of that report again. It really explains what happened back then and why it happened.
Here is part of that NOAA report.
...The meteorological conditions just described produced one of the most damaging storms to affect the eastern coastal sections of Florida during the past several decades. Much of the damage from Fernandina Beach southward to North Miami Beach, nearly 400 miles, was caused by the easterly winds of gale force with gusts as high as 60 miles an hour blowing for nearly four days. This action of the wind over the ocean produced shoreward moving swells of around 20 feet which pounded the Florida east coast and produced the most severe beach erosion in recent years in many areas. An example of the destruction was the reduction of the newly completed l100 foot pier at St. Augustine to 300 feet. Sand dunes were obliterated leaving barrier islands void of any natural protection against the next onslaught of a coastal storm in the future.To add to the destructiveness, the highest monthly astronomical tide period coincided with the highest period of storm tides which occurred on the morning of Thursday and Friday, the 22nd and 23rd. All of this produced tides 4 to 6 feet above mean yea level (MSL} at times of high tide. In some places, this was the highest tide in the last 30 years. Alt Mayport, Florida, just north of Jacksonville, the tide of 5.2 feet above MSL was the third highest tide of record. Much of state road A1A, the famous coastal highway, was closed in Indian River County between Vero Beach and Sebastian Inlet because of high water. In this area several beach front buildings collapsed, and 600 to 1,000 people were ordered to evacuate their homes. In Palm Beach County, five blocks of A1A were seriously damaged by the high tides and heavy surf. Bridges were closed because of flooded approaches which caused some barrier islands including the large Hutchinson Island to become isolated for periods of time around the time of high tide. In the storm's aftermath, severe coastal beach erosion stretched from Jacksonville to Palm Beach. ...
At the West Palm Beach weather office, a new station rainfall record was set on Thanksgiving Day for the greatest amount in a calendar day, 7.41 inches....
Another factor was that these strong onshore winds continued for many days. Winds of near gale force (about 40 miles an hour) began blowing along the north Florida coast the evening of the 20th. They did not subside until late on the 24th. Therefore, much of Florida experienced strong onshore winds for about 4 whole days. These winds were frequently between 30 and 40 miles an hour. The direction of the winds was from the north northeast which is probably the best angle of incidence for beach erosion along the coast from Fernandina Beach to Palm Beach. The coastline south of Palm Beach was spared from most of the adverse effects of the storm because the wind was actually blowing offshore throughout much of the storm. However, this northwest wind caused significant damage to the coastlines of the western Bahama Islands Friday and Saturday. This was all due to the position of the storm center remaining over Grand Bahama Island from early Thursday morning through early Saturday...
As noted earlier, the time of the month that the storm occurred was coincident with the highest astronomical tides of the month and nearly the highest spring tide of the year. Tide tables indicated that the highest predicted tides for the month of November fell on the mornings of the 22nd and the 23rd, exactly during the time of the highest storm tide. Reports from the storm survey teams of the Florida Department of Natural Resources indicate that the storm tide was over 6 feet above low mean water. Tide gauge readings at Mayport were 7.5 feet above mean low water or 5.2 feet above mean sea level. The one factor of the storm episode which magnified the entire situation was the nearly stationary nature of the storm for 3 days. This lack of movement produced the prolonged onshore winds which resulted in at least 4 days of heavy surf pounding the shore. Portions of the coastline experienced 9 high tides during this period, with each succeeding high tide higher than the previous one, thus making the erosion of sand greater with each tide. These are the reasons for the extensive damage that resulted from this particular storm....
Before commenting, here is the link if you want to read the entire report.
http://www.srh.noaa.gov/images/mlb/pdfs/Nov_1984_storm.pdf
After all of the big surf the past few days, there was more accretion than erosion along the Treasure Coast. I talked about a couple of the reasons for that yesterday. I mentioned the amount of sand in front of the beach that was absorbing most of the wave energy before the waves hit the beach, along with the angle of the waves.
You've probably heard of the legendary Thanksgiving Storm or 1984. I've mentioned it several times before and I posted the exciting story of one person that was there that day. I also posted a NOAA report that explained why that storm damaged the beaches so much. While people are wondering what happened and why the recent waves didn't do much for us, I thought it would be a good time to post some of that report again. It really explains what happened back then and why it happened.
Here is part of that NOAA report.
...The meteorological conditions just described produced one of the most damaging storms to affect the eastern coastal sections of Florida during the past several decades. Much of the damage from Fernandina Beach southward to North Miami Beach, nearly 400 miles, was caused by the easterly winds of gale force with gusts as high as 60 miles an hour blowing for nearly four days. This action of the wind over the ocean produced shoreward moving swells of around 20 feet which pounded the Florida east coast and produced the most severe beach erosion in recent years in many areas. An example of the destruction was the reduction of the newly completed l100 foot pier at St. Augustine to 300 feet. Sand dunes were obliterated leaving barrier islands void of any natural protection against the next onslaught of a coastal storm in the future.To add to the destructiveness, the highest monthly astronomical tide period coincided with the highest period of storm tides which occurred on the morning of Thursday and Friday, the 22nd and 23rd. All of this produced tides 4 to 6 feet above mean yea level (MSL} at times of high tide. In some places, this was the highest tide in the last 30 years. Alt Mayport, Florida, just north of Jacksonville, the tide of 5.2 feet above MSL was the third highest tide of record. Much of state road A1A, the famous coastal highway, was closed in Indian River County between Vero Beach and Sebastian Inlet because of high water. In this area several beach front buildings collapsed, and 600 to 1,000 people were ordered to evacuate their homes. In Palm Beach County, five blocks of A1A were seriously damaged by the high tides and heavy surf. Bridges were closed because of flooded approaches which caused some barrier islands including the large Hutchinson Island to become isolated for periods of time around the time of high tide. In the storm's aftermath, severe coastal beach erosion stretched from Jacksonville to Palm Beach. ...
At the West Palm Beach weather office, a new station rainfall record was set on Thanksgiving Day for the greatest amount in a calendar day, 7.41 inches....
Another factor was that these strong onshore winds continued for many days. Winds of near gale force (about 40 miles an hour) began blowing along the north Florida coast the evening of the 20th. They did not subside until late on the 24th. Therefore, much of Florida experienced strong onshore winds for about 4 whole days. These winds were frequently between 30 and 40 miles an hour. The direction of the winds was from the north northeast which is probably the best angle of incidence for beach erosion along the coast from Fernandina Beach to Palm Beach. The coastline south of Palm Beach was spared from most of the adverse effects of the storm because the wind was actually blowing offshore throughout much of the storm. However, this northwest wind caused significant damage to the coastlines of the western Bahama Islands Friday and Saturday. This was all due to the position of the storm center remaining over Grand Bahama Island from early Thursday morning through early Saturday...
As noted earlier, the time of the month that the storm occurred was coincident with the highest astronomical tides of the month and nearly the highest spring tide of the year. Tide tables indicated that the highest predicted tides for the month of November fell on the mornings of the 22nd and the 23rd, exactly during the time of the highest storm tide. Reports from the storm survey teams of the Florida Department of Natural Resources indicate that the storm tide was over 6 feet above low mean water. Tide gauge readings at Mayport were 7.5 feet above mean low water or 5.2 feet above mean sea level. The one factor of the storm episode which magnified the entire situation was the nearly stationary nature of the storm for 3 days. This lack of movement produced the prolonged onshore winds which resulted in at least 4 days of heavy surf pounding the shore. Portions of the coastline experienced 9 high tides during this period, with each succeeding high tide higher than the previous one, thus making the erosion of sand greater with each tide. These are the reasons for the extensive damage that resulted from this particular storm....
Before commenting, here is the link if you want to read the entire report.
http://www.srh.noaa.gov/images/mlb/pdfs/Nov_1984_storm.pdf
Notice that the report says, The direction of the winds was from the north northeast which is probably the best angle of incidence for beach erosion along the coast from Fernandina Beach to Palm Beach. As is often the case, the wind has been shifting the past few days. It started from the north and one person said they saw some cuts (Saturday I think it was), but they disappeared a day later. Often that is what happens when a front moves through: the wind shifts around as the front moves through. As the direction changes the swells change and the sand moves one way and then another.
Unfortunately we're going to continue getting changes in wind direction as another front moves through. However, I'm still thinking the biggest problem is the tons of sand piled up in front of the beach.
Knowing when and where to go isn't an exact science. You can learn enough to improve your chances considerably, but there will still be hits and misses. If you get it right every time, you're a lot better than I am. I go out to check to see what is happening. Sometimes I'm surprised and sometimes I see exactly what I expected. If you go out after a long period of south winds and small surf, your chances of finding any old treasure coins is very slim. As with many things, learning is a matter of probabilities. In fact I say that skill is a matter of doing the things necessary to improve the probability of success.
I don't know if I've ever said this before, but I believe that heavy rains can add a little to erosion by agitating the top layer and cliff faces. I have no idea how significant that might be, if at all.
I think the NOAA report on the Thanksgiving Storm is worth studying. It tells you what caused one of the most legendary treasure beach days ever.
One factor they do not address is the longer term changes that occur over years or decades. It seems to me that there are times when you have net erosion or accretion that occurs over a period of years. I can remember times when that big sand bar was not in front of John Brooks beach and if you stepped off the front of the beach into the water there was a drop off. There were pot holes right in front of the beach. The bottom wasn't covered with a layer of sand. That lasted for some years, but it hasn't been that way for at least a few years now. In my opinion, that has a lot to do with why John Brooks has not been too productive in recent years.
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We have consensus on yesterday's mystery find. Lloyd D., Joe R., William M. and Bill P. all said it is a sheet music holder. Thanks guys.
No other ideas offered, so I think that is it. Below is an example from Pinterest.
The holes were for attaching the shelf and some of them had other attachments for holding the sheet music firm, which explains some of the other holes.
The interesting thing would now be to see if there is a story behind it and how it ended up where it was found.
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Happy
