In November of 2018 Aquatica Submarines shipped a three person submarine, Stingray 500, across frosty North America on the back of a truck then over the rolling winter seas of the Gulf of Mexico to Belize aboard the R/V Brooks McCall. Our destination was a site located 7 miles into Lighthouse Reef – a perfect sinkhole in the ocean known as the Great Blue Hole. We traveled to this UNESCO World Heritage site to explore and document a geologic phenomenon in support of conservation science and to conduct outreach. Our mission was two fold, map the Great Blue Hole using high resolution sonar and take people worldwide on this journey with us on broadcast TV. Everything we collected, from CTD data and dissolved oxygen content, to video footageand experiential data, gives us the fodder we need to tell a story about an unusual place on our planet most people have never seen, until now.
Photo courtesy Aquatica Submarines.
Geology from not-a-geologist
Over the past 14,000 years the polar ice caps, formed during the last glacial maximum, have thawed and raised sea level in steps. These defrosting events are captured in a stone record of an oceanic sinkhole in Belize. The aptly named Great Blue Hole is a collapsed cave, filled with stalactite caverns, and built up from layers of fine limestone and rougher calcium carbonate walls. The stepped rise of sea level can be seen in the form of terraces carved deeply by erosion into the otherwise vertical rock walls. Straight vertical stretches of wall are free of erosion because sea level rose rapidly during a few brief decades between each step. As each melting event took place sea level rose dramatically, as much as 100 feet in 100 years, followed by centuries of stability. Preserved from the disturbance of time, and isolated in the darkness, the hole holds clues to a very natural part of our planet’s life cycle. It’s these terraces and stalactites we set out to map.
Hagfish appear to use slime to avoid predators like sharks (top) and large fish (bottom). The images above are from videos showing fish eating a hagfish, which then produces slime and is able to escape (Images from wikimediacommons).
I missed this over the summer, but Nash was an incredible guide and touring ancient Chamorro caves with him was the highlight of my time in Guam. He will be missed by many: Traditional seafarer Ignacio ‘Nash’ Camacho dies.
Ignacio R. “Nash” Camacho, a Traditions About Seafaring Islands member, and codesigner of the Chamoru Sakman outrigger replica canoe “Tasi,” talks about his creation during a ceremony at the Guam Museum on June 29, 2017.
Friend of the blog and submarine legend Erika Bergman is leading an expedition to Belize’s Blue Hole! Follow along as she maps this unique ocean feature: Belize Blue Hole 2018. Some dudes are tagging along, too.
Climate change affects the natural, built, and social systems we rely on individually and through their connections to one another. These interconnected systems are increasingly vulnerable to cascading impacts that are often difficult to predict, threatening essential services within and beyond the Nation’s borders.
