Bermuda: The Formation:
|Bermuda was formed about 100 million years ago by volcanic eruptions along the Mid-Atlantic Ridge, so Bermuda is just a "volcanic sea mountain."|
Around this time, the Atlantic Ocean was a lot narrower so Bermuda was closer to Europe and Africa, but due to sea floor spreading, plate tectonics, and the widening of the Atlantic-Bermuda got shoved away from the Eastern hemisphere, all this time still managing to never move far from its position to the North American coast.
After this move, the volcano became extinct....but this wouldn't be too good of a story if it stopped here....
Then about 30 million year the volcano decided to erupt again, which some believe to be due to it floating over a hot spot, after this incident the volcano became extinct yet AGAIN.
The people of Bermuda don't think that the volcano will erupt again soon, so all is well. An interesting fact is that this Bermudan volcano has two mouths, but both are found underwater. One is at Hamilton Harbor, and the other is at Castle Harbor!
The top of the volcanic seamount got eroded below sea level and then corals began to grow around the margins in the early Pleistocene, which takes us back to a look at the unconformities.
Today the volcanic rocks are now seen as basement rock for a limestone platform.
The limestone that formed atop originated as carbonate sand from the reefs that formed dunes, these got cemented together through the action of rain into rock.
Facts about Bermuda:
|Location including geographic coordinates:||North America, in the group of islands in the North Atlantic
ocean, east of South Carolina in the United States. It lies 570
miles off the coast of North Carolina in the Unites States. Geographic
coordinates are 32 20 North, 64 45 West
The map is a map of Bermuda from the source http://www.exxun.com/Bermuda/b_mp.html Click to enlarge the thumbnail.
The bigger map on the bottom is a map of Bermuda that shows about how many miles it is from Bermuda to popular places closer by. This is from the source http://bermuda-online.org/abcbda2.htm
The black and white map shows where Bermuda is located relative to the Bahamas, and just another look at Bermuda. Click to enlarge the thumbnail. Picture from the source http://minerals.usgs.gov/minerals/pubs/country/maps/95240.gif
The small world map shows Bermuda in relation to the rest of the world. The little star is Bermuda, you can not even really see a place under the star, but it is there. :) Click to enlarge the thumbnail, because that might also help in viewing the map. Enjoy! This picture is from http:/www.graphicmaps.com/webimage/countrys/islands/caribb/bermuda.htm
|Area:||53.3 square kilometers or 21 square meters, about 1/3 the
size of Washington, DC.
This is a thumbnail picture of Bermuda, from the source http://www.colby.edu/~ragastal/Bermuda.htm
|Climate:||Subtropical; mild, humid; gales, strong winds common in
The charts on the side are from http://www.free-weather.com/St.-George-Bermuda.php?nav= and it shows the temperature, humidity, precipitation, and average wind speed of St. George's in Bermuda. You may click on the images to enlarge the thumbnails.
|Extreme Elevations:||Atlantic ocean in the lowest point at 0 m, while the Town Hill is the highest point in Bermuda at 76 m.|
|Natural Resources:||Limestone and the temperature for the amount of tourism.
This is a thumbnail picture of Bermuda's pink beaches and limestone cliffs, at "The Reefs". So an excellent picture of the two natural resources, you get a sense of the temperature, and a picture of limestone cliffs. Source for this is http://www.theinformedtraveler.com/e_article000124039.cfm
2001, Bermuda's land use consisted of 55% developed land, 45% rural or
open land, and 20% arable land.
Thumbnail picture of Bermuda and some of the developed land and open land space shown. Source is http://home.comcast.net/~kerrydeare/bermuda_87_2.htm
|Natural hazards and ocean dangers:||Natural
hazards in Bermuda are hurricanes through the months of June to November, tropical storms,
and gales, while ocean dangers
consist of rip currents, sharks, and the Portuguese man of war.
The picture at the top left is of a satellite image of a hurricane from Northeastern Bermuda taken on Saturday September 19, 1992. While the picture right beside it is of a North Atlantic tropical storm coming for Bermuda on Wednesday June 28, 1995. Pictures are from http://www.tamug.edu/cavebiology/Bermuda/satellitephotos.html
The picture at the bottom is of a rip current from the source http://www.ripcurrents.noaa.gov/overview.shtml
While the picture on the top at the far right hand side is showing a rip current from Delaware Sea Grant and shows aerial view of more than one rip current given by Dr. Wendy Carey and found http://www.ripcurrents.noaa.gov/graphics.shtml You may click on this image to enlarge the thumbnail.
|Environmental issues facing Bermuda:||Asbestos disposal, water pollution, preservation of open
space, and sustainable development.
A picture of the beaches in Bermuda, not full of water pollution but it is still a major environmental concern facing Bermuda because the beaches are a main tourist attraction. The thumbnail picture from source http://ersoy.org/Bermuda2.htm
|Interesting water fact:||Bermuda
consists of about 138 coral islands with ample rainfall, but no rivers or
freshwater lakes. No
fresh water in Bermuda, even the roofs are set in a way to maximize water
Thumbnail picture of a roof in Bermuda, to show how they get their water from the rain. Source of picture is http://spas.about.com/library/weekly/aa090602d6.htm
The bigger picture is also of a roof in Bermuda, to show how they extract the rain. A picture to show the differences, picture from http://www.dreamingofbermuda.bm/roof.html
|Bermuda flag, click to enlarge. Source is http://www.cia.gov/cia/publications/factbook/flags/bd-flag.html||One of Bermuda's beautiful beaches. Click to enlarge. Source is http://www.colby.edu/~ragastal/2002Itinerary.htm||Another picture. Click to enlarge. Source from http://www.dreamingofbermuda.bm/|
Bermuda Caves-Let's Venture Inside...
|More than 150 caves are found in Bermuda, and all are formed in this limestone cap rock. These caves contain many stalactites, and stalagmites. Although many of the entrances to the caves are inland, some caves extend down to sea level and contain pools of water.|
|Bermuda's longest cave is Green Bay Cave System and is completely submerged in water, this cave also contains about 2 km of explored passageways, while most other caves average in 18 meters of passageway.|
|Underwater caves that contain stalactites and stalagmites are proof of the idea that during the Ice Age, caves must have been dry for prolonged periods of time.|
|In Bermuda's anchaline caves comes new species that were previously unknown to man, and there are 75 aquatic cave adapted species that have been identified from caves including: 64 crustaceans, 5 mites, 2 ciliates, 2 gastropod molluscs, and 2 segmented worms.|
Specific Caves in Bermuda: this is a map of the Crystal Cave and Fantasy Cave location. The source of this picture is http://www.bermuda.com/CrystalCaves/pages/indexhistory.html
in Hamilton Parish, Bermuda this karst cave is 500 meters in overall
length and in the 1990's fossil bird bones were dated back several hundred
thousand years ago, and found by the Smithsonian Museum. At this
cave David Milne Holme calculated the age of a stalagmite to 600, 000
years old in 1864. David Milne Holme was the son of the British
Admiral that first came across this cave. This cave is one of the
largest dry caves on the island and has three entrances, one being a large
sinkhole entrance. there are small lakes that are found inside the
cave, specifically 5 of them, and they lead back to the sea to show wave
Picture of Admirals' Cave thumbnail, click to enlarge, the source is http://www.tamug.tamu.edu/cavebiology/BeCKIS/images/Admirals1.jpg
Picture on the top as well that is in full size is from http://www.tamug.edu/cavebiology/Bermuda/images/Admiral1.jpg
Picture on the bottom is of the fossil bird bones found, the source is http://www.tamug.edu/cavebiology/BeCKIS/hotspot.html
also in Hamilton Parish, but more specifically in Grotto Bay Beach
Resort. This cave was one of the first five to be in
Joyce's Dock group, which is situated in the location of Grotto Bay Beach
resort, and the location is also right beside Prospero's cave. Many
people believe these two caves are connected, and maybe share a water
pathway. The main feature to the cave is a large, and quite deep
lake. After the hotel was built in the 1960's the guests would
frequently use the lake in the cave as a place to swim without the weather
getting to them. The lake in this cave is tidal, just like all the
other lakes in caves that are found in Bermuda. The lake inside this
cave is also formed by sea water migrating through fissures in the porous
rock that is around the cave.
Click to enlarge the thumb nail image. Picture from http://www.tamug.edu/cavebiology/Bermuda/images/Church1.jpg
again in the Hamilton Parish, along with the rest so far, but this more
specifically is Wilkinson Avenue, Bailey's Bay. This karst cave is
also 500 meters with 350 meters underwater, and a vertical range of -62
meters. This is also one of the most interesting, and most known
caves in Bermuda-and if you believe it was discovered through child's
play. March 1904, Carl Gibbons and Edgar Hollis were playing, and
lost their ball and after moving around some rocks to locate their missing
ball they found a hole. March 17, 1907 Percy Wilkinson, his father
and three brothers were shown the entrance of the cave by John Hollis, and
the exploration from the Wilkinson's began there. The next day they
sent out to search this cave and found crystal stalagmites and stalactites
which circled a lake of 16 meters deep. This cave was then opened to
the public by the Wilkinson's January 8, 1908 and even Jim Henson went to
Click on thumb nail to enlarge, picture from http://www.tamug.edu/cavebiology/BeCKIS/images/Crystal1.jpg
The picture beside it, is also in the Crystal Cave. Picture from http://www.tamug.edu/cavebiology/Bermuda/images/Crystal2.jpg
|Fantasy Cave||Discovered in 1907 by Arthur Elystan Haycock when a hole in his property gave out a draft, and he turned to Carl Gibbons and asked him to investigate the hole. Carl Gibbons was asked to make trails and a concrete staircase from the surface to the lake, and then in 1912 was opened to the public as Wonderland Cave. After a while it was closed and gated in 1931, and only in 1999 did redevelopment begin again. In July 2001, the cave was finally opened to the public eyes again, and this time under the name Fantasy cave.|
is in Hamilton Parish in Grotto Bay Beach Resort, and this is one of the
first five caves to be in Joyce's Dock group, along with the Cathedral
Cave. It was said to be discovered in 1609-1610 by Sir George
Somers, which would mean this may be the first cave to have been
discovered in Bermuda. The cave was first called the Island Cave,
after it was named Prospero's Magic Cave, and now as Prospero's cave for
short. in order to get into the cave one must go down a short flight
of stairs that leads to deep lakes and if you look above there are stalactites.
Now the cave has a little bit different of a make over, and also contains
an underground bar, and discotheque.
Picture of Sir George Somers, found from http://www.bermuda-online.org/sirgeorgesomers.htm
Extra Bermuda Cave facts: (picture below sourced from : http://bermudashorts.bm/crystalcaves/ )
|Although many people think Bermuda caves are strong and can not be ruined this is not true. The things that threaten Bermuda caves are such thing as:|
|dumping sites and|
|and construction and quarrying activities.|
|Many of Bermuda's caves have already been used as dumping sites.|
|While these caves have still remained intact, there are some caves that have collapsed that are now used for other such things: such collapsed caves include Blue Grotto, and the Devil's Hole.|
Bermuda's Pink Beach Sand-What's Up With That?
Pictures of the beaches of Bermuda, showing off their natural "pink" tint. Sources from http://www.bermuda-online.org/beaches.htm
|The Bermuda beach sand isn't volcanic sand at all, but rather the fine remains of the calcium carbonate shells and even skeletons of invertebrates.|
|Such invertebrates are corals, clams, and forams, among other little shells.|
|Forams-dark red skeletal animals that grow like wild fire on the underside of "the Reefs" of Bermuda.|
|When the red forms die, the skeletons fall to the ocean floor, wave action erodes the forams|
|The wave action lets the forams mix around with other debris that happen to be on the seabed which would consist of white shells of clams, snails, and sea urchins. (Think of the same type of wave action that oolitic limestone endures, and the wave action that helps the limestone collect other debris.)|
|After this wave action and the mixing, the white sand then takes on its known pink hue.|
|Information provided here from http://www.bermuda-online.org/beaches.htm|
Another interesting fact about Bermuda's beaches: Erosion and Beaches? What are you Talking About?
|Coastal erosion and deeper sea surges are said to be the next big thing for Bermuda due to global warming.|
|Although right now this is only a prediction done by Dr. Wolfgang Sterrer at the Bermuda Natural History Museum, this already has truth.|
|At certain times of the year, a major section of the sands of Elbow Beach and the nearby Stongington Beach are washed away.|
|Bermuda's coastline has also eroded by between 20-30 centimeters in the last century, and this was noted by Dr. Sterrer, and now scientists are even believing that with more global warming, further erosion of up to 100 centimeters will take place in the 21st century.|
|Information provided here from http://www.bermuda-online.org/beaches.htm|
In Summary (just a quick note, to fully explain what points in this website had geologic significance if it was not clear):
Bermuda has lots of information pertaining to Geology, and geologic concept. Some are seen easily at face value, while others are not. Seeing as this is a page for geology, mainly every piece of information has a geologic concept, or geologic significance behind it. The formation of Bermuda, was the most major and eye catching process, and then to learn it has everything to do with geology was even better. Seeing as Bermuda began with volcanic activity, continued with plate tectonic activity and sea floor spreading and then the volcano was pushed over a hot spot, which sent the extinct volcano into an erupt, and created Bermuda. Then after the volcano became dormant again, the top began to erode away, which reminds us of one of the processes of unconformities, and after getting eroded away life takes its course and begins again, this time creating a platform of limestone. So the formation of Bermuda did not deal with just one thing, it dealt with a little of everything. It dealt with the plate tectonics, sea floor spreading, the creation of a volcano over a hot spot, as well as the final steps which are hypothetically one of the unconformities. Enjoy!
Other Cool Sites to Look at:
http://www.bermudasun.bm/archives/2002-06-26/01News11/ Actually this is an article in the Bermuda Sun, but it talks about the Admiral's Cave, so enjoy!
http://www.tamug.tamu.edu/cavebiology/Galleries/BeCKIS-02/index.htm This is the website for more cave pictures, there are really neat and interesting. Take a look!
http://www.bermuda.com/CrystalCaves/pages/indexvirtual.html This is a website where you can see a virtual tour of both the Crystal Cave in Bermuda, and the Fantasy Cave.
http://www.bermuda-triangle.org/html/introduction.html This is a good site to read up on the mystery of the Bermuda triangle. Just when you thought Bermuda couldn't get any more interesting!
http://www.dreamingofbermuda.bm/ This website has lots of interesting pictures, and information about Bermuda.
http://www.bermuda-triangle.org/html/introduction.html I did not include this information, because it is not geologic, and I know we were supposed to keep this assignment with the geology roots, but this is unexplainable and very known facts about Bermuda. For example, I knew about the Bermuda triangle, before I ever knew about Bermuda. Very interesting information and a real mystery case, true and unsolved. Enjoy!
http://www.bermuda4u.com/Essential/bermuda_triangle.html This is another really cool page about Bermuda triangle, although it does NOT go into detail about the whole scenario it gives a very brief overview but is still interesting.