Feb 5, 2016

Resilience by Sherry W.

January 6, 2016

Before coming to the United States, I had never heard of caving. Our school group headed to Lighthouse Cavern. This was the very first time I had ever gone caving. The proper term for this hobby is called 'spelunking' which involves exploring cave conduits.
 
Entrance of Lighthouse Cave. Photo source: https://www.flickr.com/photos/jsjgeology/16321380981
 
Upon entering the cave, under the darkness of the main chamber, I had a mixture of emotions going through my head. Normally, I would be afraid of such a dark and closed-off environment - one that I'm not familiar with. At the same time, I felt super excited to explore something so foreign and new to me! It was an interesting mix of feelings.  
 
The dry main chamber of Lighthouse Cave is decorated with a beautiful array of thousand-year old speleothems. Columns, draperies, stalactites, stalagmites, and bell holes can all be observed! Photo source: https://www.flickr.com/photos/jsjgeology/15705358684  
Transitioning from dry cave to a submerged tunnel was a fun shock. For one, the water here is a mix of salt and fresh that is refreshingly chilly. I followed the others in a single line as my headlamp illuminated ahead of me. The journey was relatively dark, and thoughts of creatures living beneath the water creeped into my head...I was afraid, but the idea of exploring something new propelled me forward. 
 
Entering the submerged phreatic zone of the cavern.
 
These headlamps were our guiding light!
 
 
We trekked further into the cave and into deeper water. At one point, my feet could no longer touch the rock below and began to swim in order to explore further. All over, I could see incredible formations on the cave walls. Once we reached the end of the cave, there was an 'island' of limestone where we were able to rest on. It was here when we turned off all of our headlamps and felt what is was like to be in complete darkness. Nowadays, people rely too much on technology and don't take the time for serenity and meditation. This experience was unique and unforgettable for me.

Feb 4, 2016

Salt Pond by Dana Y.

 
January 11, 2016

This morning Lisa had a discussion with us about sustainability for San Salvador. We learned that there are nine types of sustainability. They consist of energy, food, jobs, transportation, water, education, shelter, waste management, and outreach. The one I find most interesting and want to do my project on is education. I think that if the education system teaches sustainability from an early age then it can have an impact on the other eight types of sustainability. Learning about all of this was my favorite part of the day.

In the afternoon we did a beach profile of the dunes on Junk Beach. We found that from the hurricane the debris had traveled about 42 meters from the ocean’s edge. This means it had to have traveled up and over the dune, across the road, and deposited on the edge of the hypersaline Salt Pond. Some of the debris consisted of netting, a variety of plastics, some metal scraps, and medications. It was super interesting to see how much this hurricane truly impacts this island.




Salt Pond lake is located on the eastern side of San Salvador Island. It's also interesting to note all of the inland lakes. https://en.wikipedia.org/wiki/San_Salvador_Island#/media/File:SanSalvador_map.jpg 
 
 At Salt Pond, we also took core samples. You may notice the water in this inland pond is neither clear nor blue. Why is that? When Salt Pond formed, it was separated from the ocean by dunes that created a barrier to the sea. This cut-off basin then began to collect rain water and even overwash from the sea in times of storms. Who lives in these waters plays an even bigger role in the color of the water. A community of microbial mats call this pond their home and give the water its brownish-red glow. The mats are made of thin layers of bacteria that grow beneath the water surface. They play a role in the dynamics of the pond by influencing the precipitation and dissolution of carbonates.


Microbial mats. You may be familiar with the ones from Yellowstone National Park (left). On the right is an image of a profile of layered mats.
 


Photograph of Salt Pond. View is to the west. The core sample was taken from this portion of the pond to see the transition of various mats through depth.  


In order to understand the microbial mats better, we got a push core of the pond floor. We walked out about 40 ft. into the pond in order to get our core. The bottom of the pond was extremely gucky and difficult to navigate since my feet kept sinking into the floor! We hope to analyze how the mats change in varying water depth.  

Feb 3, 2016

Australian Invasion: Casuarina induced erosion by Melissa N.

January 2016

On San Salvador, we looked around the island at everything from rock formations to coral reefs. I was interested to learn about the invasive casuarina. This Australian pine was brought to the island (and all of the Bahamas) in hopes of stabilizing coastal dunes during storms. Sadly this pine had the opposite effect.

Australian pines. Image by Meg Stewart https://www.flickr.com/photos/megstewart/4320102993


The casuarina has a shallow root system that can easily be ripped out under the stress of the frequent hurricanes. Once the roots become dislodged, the dune is ripped up giving way to the processes of erosion. The dune eventually loses its profile and becomes unstable.
The casuarina also has needles that cover the ground below the tree. These needles block sunlight penetration to the soil and acidify the soil surrounding the tree. The casuarina not only rips up the dunes, but also halts the growth of any vegetation that could stabilize the dune.

Figure shows a profile of dune erosion caused by cauarinas. Figure by http://www.geraceresearchcentre.com/pdfs/10thNatHist/113_Sealey_10thNaturalHistory.pdf

Photograph of a foreshore on San Salvador Island. Casuarina trees can be seen in the upper right hand corner of the image.

Image shows beach erosion caused by the Australian pine. Photo by https://casuarinacontrol.files.wordpress.com/2011/07/casuarina1.jpg

So what does all of this mean for the island's future? Dunes serve to protect the land in times of storms. Think of them as buffers for local homes located on the coast. When Hurricane Joaquin struck the island on October 2015, it brought powerful winds and swells that eroded sand away from dunes. Beaches on the eastern side of the island were particularly affected. Australian pines are speeding up the erosion process. What can be done about this? For one, the Australian pine has a very dense and heavy wood that withstands water. The trees could be harvested and made into furniture for export which would boost the island's economy and create a market for Bahamian furniture.  

Sources and further reading:

The cycle of casuarina induced beach erosion by Neil Sealey

Snorkel Outings by Logan M.J.

January 2016


 
I had a fantastic time on the UCONN Bahamas Study Abroad adventure. Although caving and studying beaches was fascinating; the ultimate activity was snorkeling, which luckily we were able to do nearly everyday. Every time our truck stopped, we were all hoping we would be able to bring our snorkeling equipment. I cannot express in words the excitement we felt when we learned we were able to go snorkeling after doing field research. It was the coolest and most refreshing break.

The dark areas in the water pictured above are beds of sea grass (thalassia). They are havens for baby fish and make a great feeding ground for turtles!

Off to the races!


Swimming amongst the colorful reef fish was pretty much one of the coolest experiences of my life. Seeing the bright corals amongst diseased corals was fascinating as well. Knowing that parts of the island were made from ancient coral reefs was really interesting to learn. The weirdest thing was definitely learning all of the coral names throughout the trip, so at the end of the trip I felt like the ultimate coral naming professional!

The highlight of the snorkel trips and maybe the whole trip overall were when were able to swim with multiple sea turtles and when me and my snorkeling buddy spotted a huge stingray! It was very cool, very mind blowing and I hope someday to go back!
Check out the pattern on this little fellow! Very impressive.



 

 
 
 

Jan 15, 2016

Final goodbye on Grotto Beach

January 15, 2015



Our last day at GRC was one of the most memorable. With all of our daily exercises complete, we had the day to enjoy as a group one last time.

 In the morning, our groups gave presentations on future sustainability plans for San Salvador. Transportation, food, energy, waste management, jobs, education, and outreach were all addressed. Sarah and I were in charge of 'outreach' that would bring together these ideas and the local community. The overall goal is to encourage San Salvadorians to take a closer look at the sustainability of their island and highlight how Bahamian life is connected to the ocean. 

 Sarah had the wonderful idea of creating a website that would showcase the island's geology, facts, and sustainable practices. This is a project I would like to expand on and share with the San Salvadorians to show them potential opportunities for them and their island.

 Our presentations and discussions lasted until lunch time, and at 1:30 p.m. we set off on the trucks one last time. We decided on Grotto Beach - located on the south side of the island. En route to our destination, a storm cloud followed us and it began to pour. Some of us embraced the rain, others not so much, but it made for a very memorable trip! We all voted to keep forging ahead, determined to spend our last hours at this beautiful beach. As we approached our destination, the sun was there to shoo away the passing storm. Success!




Grotto Beach seems to host the bluest and most crystal clear wasters. The waves were just right for body surfing. Some of us were able to 'surf' up the foreshore about 25 ft from where the waves broke. Records were set.  


As the sun shifted from east to west and began to set, we all gathered to have our final sand castle and cartwheel competitions. Today was a good day. 




   

Jan 11, 2016

Green Cay: Visiting Iguanas

January 11, 2016

A very curious iguana! Photo courtesy of Bruno Shkembi

Today's forecast: sun, breeze, and an appetite for adventure! We were finally set to visit the iguanas of Green Cay. This remote island is home to the unique San Salvador rock iguana. After lunch, we met with Captain Bruce and his dog Jazzy at Graham’s Harbour. We sailed twenty minutes to the offshore island where we anchored the boat just 20 feet from the jagged shore. We were instructed to don our snorkel gear prior to entering the water. The short swim to the island was enjoyable as there were patch reefs with colorful parrotfish along the way.




The smooth gentleness of the water gave way to rocky slope covered with shells and dead coral. Upon reaching shore, I threw my fins and gear onto the island and carefully climbed up. The vast majority of the island is composed of a jagged, sharp limestone that makes it near impossible to walk the terrain without boots. I don't know how the iguanas do it.
Greetings from Green Cay! As you can see the island is very jagged and sparse, but home to edible succulent plants!


About a minute into our trek, a small greenish yellow iguana greeted us. Why was it so eager to see us? The answer is food! Many tourists come prepared with lettuce to give the iguanas. A few more iguanas snuck up behind us, curious of one of our group member’s video camera! In total, we saw about eight iguanas on Green Cay. The San Salvador rock iguana is an endangered species native to certain remote islands of the Bahamas. It was a pretty neat sight to see a larger iguana on San Salvador itself. It was spotted twice by Graham's Harbour on North Point. I take this as a positive sign of the iguana's return to the island.
Photo by geoscience major, Bruno Shkembi

A look at the north side of Green Cay Island. The ocean has eroded the limestone to create sea caves and inlets. Photo by Bruno Shkembi








Jan 6, 2016

Lighthouse Cave

January 6, 2016

Today was super special for me. We trekked to Lighthouse Cave, located on the northeastern edge of the island. I was super excited to visit this site since my interests include the karst dissolution of caverns and sinkholes (blueholes) – which this island has many of. 

Dissolution feature on the island: Watling's Blue Hole

Another common dissolution feature on San Salvador Island; banana holes.


Ladder leading down to the Main Room
The cave was a short drive from base and is situated downhill from the 200 year-old lighthouse which is still in use. With us, were two machetes, in the event that we encountered heavy brush. At the end of this muddy path was what we came looking for: the cave entrance. The opening was a straight 15-foot drop. Luckily for us, there was ladder to make our way down the main entrance. The entrance is a collapse pit cave with a chamber that intersects the water table. Going down the stairs, the cavern smelled musty, its darkness broken up only by the light of our headlamps. The cavern floor was made of slippery limestone, which led to a submerged pathway further down. The tidal range is this cave is about 3 feet and we entered at low tide (10 a.m.), although we were surprised when we swam through areas where the water went up to our chin. Due to yesterday’s (January 5th) rain event, the water table was a little higher than we had expected. In a single file, we all swam with our headlamps through a maze of stalactites and curved walls in all sorts of variety that kept our heads looking in all directions.

A number of observations could be seen, the most prominent being the abundant speleothems. Stalactites, stalagmites, and curtains could be seen decorating the ceiling and walls. Bell holes are another karst feature of this cave that are known to house bats.
Panorama of the Main Room

The cave was rather small and ended at a small round chamber where we all gathered to take a group photo. On the way out of the cave, I hit my already injured knee on a limestone ledge that caused it to open up again. We followed the mud-lined path back to the parked truck and made our way to the top of the hill where the Dixon Hill lighthouse stands guard.

Dixon Hill Lighthouse

The group spiraled up the lighthouse where we were treated a 360 degree view of San Salvador. It was a beautiful panoramic display of tree cover, lakes, and teal blue waters.

Our exercise for the day was completing a dune profile of one of the beaches on the eastern coast. We were shocked at the amount of bottles, plastic, and parmesan cheese containers that was washed ashore. Curious to see its origin, I picked up a whipped cream can and saw it had made its way from Puerto Rico. I’m not sure if this was a result from Hurricane Joaquín or if this normally washes onto these beaches by currents.
Update: During October 2015's Hurricane Joaquin, a cargo ship crashed off shore, losing all of its cargo to the sea. Frontline flea & tick medication, parmesan cheese, and other products washed ashore and can still be seen to this day.   





Splendid views all around! Many thanks to Bruno who got a whole bunch of amazing shots with his GoPro!


  

Jan 3, 2016

Cockburn Town Fossil Reef

January 3, 2016

Waking up, today did not feel like a Sunday. It is only our third day on the island, but it feels like we have been here for much longer. Our morning began at 6:45 a.m. with a magnificent view of the sunrise as we made our way to breakfast. Soon after, we all met in the conference room to go over today’s schedule and share what we have learned so far. We packed up our snorkel gear, hopped on the trucks, and made our way down to our first stop: Cockburn Town Fossil Reef.


Panoramic view of Cockburn Town Fossil Reef

The Pleistocene fossil reef is a true paleo-gem, with an outstanding combination of fossils and lithified dunes. Our objective is to compare fossil and modern reef environments to learn how to construct a stratigraphic column and interpret biofacies changes with respect to sea level fluctuations. 

The carbonate lithofacies of the Cockburn Town Fossil Reef were deposited during a global highstand of sea level that occurred around 120 thousand years ago. Everywhere we looked, we saw fossils. The most notable and abundant included: palmata, monastrea, porites, elkhorn coral, mollusks, bivalves, and brain coral. Overall, sea level has been in regression although it has fluctuated between phases of transgression and standstill phases. It was interesting to note that dune cross bedding was found near reefs which are deposited underwater.


Close up photograph of fossilized diploria, more commonly known as brain coral.


These tidal pools that form on the reef make great homes for modern-day gastropods.


Our daily exercise culminated in us meeting with a local on the reef. The local was very
upset by a pipe leading from the Bahamas Electric Corporation (BEC) to the water and Cockburn Fossil Reef. It is possible the pipe may be leaking diesel or other liquids into the local groundwater and sea. At the same time, it is this diesel and electricity company that powers the island. Supplying power to the island comes with a cost. Clearly, locals are concerned with the well being of their island and how companies are affecting it. Companies should communicate to the locals what they’re doing and what precautions are being taken to conserve the environment. There needs to be a bridge between the two parties in order to create a sustainable future for the island. Moving forward, locals should be informed about their geology, as do the engineers and companies that work on the island. How can this compromise be met?
Update: We later found out that this is an intake pipe for the island's diesel supply which provides electricity for the entire island. It's surprising how this pipe is not secured more properly.
Photograph of intake pipe sitting a top the Cockburn Town Fossil Reef leading to the Bahamas Electric Corporation.

Jan 2, 2016

New Routines: First Day at Gerace Research Centre by Sam L.

January 2, 2016
 


The first day anywhere new is always the strangest...new routine, new places, and new people. When I first woke up it even took a moment to remember that I was actually in the Bahamas. After a quick breakfast and morning lecture on the basics of the island's geology was on the menu. It was interesting seeing how far into the Atlantic the island of San Salvador is compared to the rest of the Bahamas.




San Salvador from space! Satellite image from Earth Observatory, NASA
 http://earthobservatory.nasa.gov/IOTD/view.php?id=76134



Queen's Highway, a ring road that circles the entire island. View from the entrance of the Gerace Research Centre.  



Sunglasses on. Top down. Music blaring. Catch us riding in style!









Pristine conditions at the former naval docks (Graham's Harbour).


 

With the lecture down and our stomachs full it was time to pile onto the truck and roll out. The first stop brought us down the road to the old naval docks, which have seen better days to say the least. Here we talked about a variety of topics including the composition of the sediments, trace fossils, and aeolian processes that helped shaped some of the rocks in the foreshore and backshore. These sections was part of the geologic unit known as the North Point Member. 


Geoscience student, Logan Mort-Jones, sits a top the North Point Member which belongs to the Rice Bay Formation. This formation is the youngest on San Salvador and was deposited during the start of sea level transgression in the Holocene.
 










Geoscience majors taking a closer look at the eolianite cross beds of the North Point Member.
 
This was the general gist for the day. We would pile onto the truck with music blaring, some laughs being had and arriving at another beautiful beach scene which always hidden gems for us to observe and learn about. An interesting stop was at the sea wall that currently being constructed. We were able to observe the damage San Salvador had endured from Hurricane Joaquin and the resilience of the island. The sea wall in particular was being built to help protect the road from being eroded. Gaps were made in the sea wall every few feet to help relieve water pressure in case there ever was to much for the wall to handle.


The newly built sea well is located by Cockburn Town.
 

 
 
 
 
 
 
 
 
 
 
 
 
 





Fossilized brain coral on the sea wall.


Below the sea wall, large chunks of coral visible as well as paleosols. The paleosols were formed when sediment was blown from the Sahara and mixed with the sediments already present on the island, which were oxidized through time. This is also an important feature because the paleosols also help to mark the boundary between two of the geologic formations. 

A quick final note on the best part of the day, in my opinion, involves the coral reefs around the island. The corals and life within are beautiful. The reef we visited had some visible bleaching and damage, but also some regrowth as well. This was a good warm up snorkel and definitely just the beginning of what I can expect to be an amazing experience.
 

Some more shots from today's trip to the southern end of San Salvador:

 
A great display of cross bedding on lithified dunes on the south end of San Sal.

Boulder field on the southern side of the island caused by Hurrican Joaquin.

 

An outcrop on the south end of the island (next to the boulder field).