Where to see the northernmost coral reefs in the Atlantic, how to tour two caves formed from karst erosion in limestone, and the best spot to enjoy Bermuda's national drink, the Rum Swizzle.
When I was teaching, I had the pleasure of accompanying students on a Study Abroad trip to Bermuda. Known for its clear waters and pink sand beaches, the northernmost coral reefs in the Atlantic Ocean are found there. Bermuda also boasts a diverse marine biosphere and interesting geologic sites. Let’s dive in! 🐠
Sharon Lyon
Editor, GeoLifestyle
About the Island
Standing on a pink sand beach in Bermuda, surrounded by lithified carbonate dunes (eolianite)
Bermuda is a series of small carbonate islands along the southern rim of a volcanic seamount. The seamount formed in the early Cretaceous near the axis of the Mid-Atlantic Ridge then moved westward by seafloor spreading, sinking below sea level.
Geology details:
In the early Oligocene, the area was reactivated and intruded by lamprophyric sheets, which raised the seamount as it moved over a hot spot.
Once in shallow water, carbonate-secreting organisms established reefs around the islands.
The islands are formed from lithified Pleistocene calcareous dunes (eolianites). Brown and red paleosols sit between the stacked dunes.
Researchers have recorded Quaternary fluctuations in sea level on Bermuda, with high stands being times of carbonate production and dune formation and low stands being times of exposure and soil formation.
The carbonate dune sand was produced in warm, shallow marine environments, and prevailing winds blew it offshore. These skeletal grainstones are composed predominantly of bivalves, gastropods, and foraminifera, identical to that of modern Bermuda beaches.
Calcareous invertebrates that thrive in lagoons, grass meadows, and reefs are still producing sediments. These invertebrates include the encrusting foraminifera Homotrema rubrum, which lives on the underside of coral ledges and on coral rubble. When they die, their reddish shells mix with white calcareous fragments to form pink sand beaches.
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Seas can be rough at North Rock; An array of corals and fish live beneath the waves.
Bermuda is located 1,000 km east of North Carolina, at the northern edge of the Sargasso Sea. The platform is bathed by the warm waters of the Gulf Stream, supporting its subtropical climate and allowing corals to thrive.
There are thousands of reefs within a shallow lagoon to the northwest of the islands. Fringing reefs, patch reefs, and pinnacle- and mesa-like forms build from the lagoon floor.
The diversity of coral is less than in the Caribbean, with only 22 of the 72 known Caribbean species.
Where to see coral:
Whalebone Bay: Whalebone Bay is a public beach perfect for strolling, swimming, snorkeling, and the like.
Because it is shallow and partly cut off from the north lagoon by a line of small rocks, it is an excellent place to study the fauna and map the sea floor while snorkeling.
You can swim around the rocks to see isolated corals. Students also enjoyed night snorkeling here, using flashlights to see the nocturnal creatures.
North Rock: Located 10 miles offshore, North Rock is a spectacular place to snorkel and see the coral heads and marine life.
If snorkeling is not your thing, you can visit the museum’s 140,000-gallon North Rock Exhibit, which showcases live corals and large predatory fish.
Note: The seas at North Rock can be rough, so take precautions if you tend to get seasick.
ASU BIOS
ASU BIOS facility and the Atlantic Explorer research vessel; Courtesy of Jennifer Kling
Our group stayed and worked at the Bermuda Institute of Ocean Sciences, now owned by Arizona State University (ASU BIOS). Visiting scientists, graduate and post-graduate students from all over the world come to ASU BIOS to do their research. There are also courses for university and community college students and high school and middle school groups.
About ASU BIOS:
ASU BIOS contains multiple research and educational laboratories, boats and marine operations, classrooms, workrooms, an auditorium, and a library.
The main facility includes living spaces and a dining room.
Every morning, we ate breakfast on theback patio overlooking the turquoise waters of Ferry Reach, the three-mile-long channel between St. George Island and St. David’s Island.
ASU BIOS also owns and operates the oceanographic research vessel Atlantic Explorer. The ship docked one evening when we were there, loaded new supplies, and launched the next morning.
Our group enjoyed chatting with the visiting scientists, who were happy to discuss their work. A British oceanographer shared her research on corals with us, and an American demonstrated a prototype of the Mid-Atlantic Glider.
Crystal and Fantasy Caves
Soda straws in Crystal Cave
Two boys playing cricket discovered Crystal and Fantasy Caves in 1907. Now, the caves are two of Bermuda’s favorite tourist attractions.
Formed from karst erosion in the limestone, the caves host spectacular formations on the ceiling and 50 feet beneath a clear lake.
Fun fact: Mark Twain visited the caves during a trip to St. George and declared “the roof overhead splendid with shining stalactites, thousands and thousands of them as white as sugar.”
Trip tips:
Tour both caves, which are adjacent to one another.
Then, enjoy lunch at The Swizzle Inn Pub, home of the Rum Swizzle, the national drink of Bermuda, which combines rum, lemon, orange, and pineapple juices, Angostura bitters, and a syrup called Bermudan falernum.
If sweets are more of your guilty pleasure—or if a Rum Swizzle sparks a sweet craving for you— enjoy ice cream at Bailey’s Bay Ice Cream Parlour across the street from The Swizzle Inn Pub. The cute, pistachio-colored storefront boasts 30 flavors of homemade, all-natural ice cream.
A salute to my colleagues, geologists Jennifer Kling and Karen Bridges (Howard Community College), who have taken study abroad students to Bermuda on multiple occasions. Thanks for including me on this trip!
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