For the couple of weeks, we have been diving near the McMurdo Jetty. Our dive hole and huts are located very close to shores of Ross Island, and during our 15ft, 3 min safety stop - we enjoy playing underneath the sea ice close to shore in amongst the wondrous anchor ice.
View over the McMurdo sound sea ice. As you can see, our dive sites are actually very close to shore. Photo credit: Rowan McLachlan
Achor ice forms in the spring/early summer here in Antarctica. Supercooled water flows out from underneath the ice shelves and moves North. Although this “supercooled” water is only 0.1-0.2°C [or 32°F] colder than the surrounding seawater (the annual mean water temperature in McMurdo Sound is -1.87°C or 28.6°F) the temperature difference is enough to stimulate ice crystal growth.
Diver Rob Robbins swims amongst the anchor ice at the Jetty dive site, McMurdo, Antarctica. Photo credits: Rowan McLachlan
Beautiful, shimmering crystals form in the water column and larger crystals start to grow on the seafloor. Eventually, a giant blanket of thick interlocking crystals known as “anchor ice” forms on the shallow seafloor, growing up to 2 feet thick in some areas.
A Sterechinus urchin moves across the anchor ice in McMurdo sound. It better be quick though, or else the anchor ice may grow over him! Photo credit: Rowan McLachlan
Swimming next to this anchor ice is a phenomenal experience. As you gently graze the anchor ice, the crystals break off and float up into the water column. With light reflected in all directions, you feel like you are inside a magical kaleidoscope or surrounded by fairy dust.
Anchor ice floating in the water column. Photo credit: Rowan McLachlan
The experience of being beneath sea ice is almost indescribable. The colors of blue that pass through the cracks in the snow and ice are so beautiful - it almost reminds me of the milky way!
Photo credit: Rowan McLachlan
I have recently been trying my hand at underwater panoramas: taking multiple photos, and later stitching them together in the photo editing software, Lightroom. Here are some of my first attempts (P.S., try clicking on each photo to make them bigger on your screen).
In this photo, Andrew Thurber is swimming just below the surface of the anchor ice, whilst hovering above the anchor ice at Dayton's Wall dive site.
In this photo, Rob Robbins is on the left photographing a curious Weddell Seal that came by to check out what we were up to! Taken at Dayton's Wall dive site. Photo credit: Rowan McLachlan.
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