A submarine-shaped, slow-moving, half-blind Greenland shark about the size of a Great White Shark that feeds on polar bears' carcasses was found swimming in the deep waters of corals in Belize. The Greenland shark is slow-moving, half blind, its flesh toxic, and can live to be 400 years old. I am curious as to why it was close to the surface of warm tropical water. I would have thought the temperature change would have killed it.
From the Mote Marine Laboratory and Aquarium:
Devanshi Kasana, a Ph.D. candidate in the Florida International University (FIU) Predator Ecology and Conservation lab, was working with local Belizean fishermen to tag tiger sharks when the discovery was made. It had been a long night of fishing. By dawn, the weather had deteriorated. Storms were gathering on the horizon. The team did a last check of their lines. On the other end of one, wasn’t a tiger shark, but a rather sluggish creature. It looked old — ancient, even — and more like an elongated, smooth stone that had sprung to life. It had a blunt snout and small pale bluish colored eyes. All together, these clues led scientists to think it was a member of the sleeper shark family.
“At first, I was sure it was something else, like a six gill shark that are well known from deep waters off coral reefs,” Kasana said. “I knew it was something unusual and so did the fishers, who hadn’t ever seen anything quite like it in all their combined years of fishing.”
Greenland sharks remain somewhat of an enigma to science. What is known about them is they tend to be seen in the frigid waters of the Arctic and North Atlantic oceans. The slow-moving species is also slow growing. Yet, a life in the slow lane may benefit them, because they have been estimated to live upward of 400 years — earning them the special designation of longest-living vertebrate known to science.
Because little is known about them, that means nothing can be definitively ruled out about the species. Greenland sharks could possibly be trolling the depths of the ocean all across the world. In fact, experts speculate that they could be found all over the world, living in tropics at greater depths, where they can find their preferred low temperatures.
The waters where Kasana and the fishermen found the shark certainly get deep. Glover’s Reef Atoll — part of the Glover’s Reef Marine Reserve World Heritage Site, a marine protected area (MPA) — sits on top a limestone platform, forming a lagoon surrounded by a coral reef. Along the edges of the atoll there’s a steep slope that drops from 1,600 feet to 9,500 feet deep, which means there is cold water needed for a Greenland shark to thrive.
In the Arctic, permafrost has been rapidly thawing as the Arctic has warmed by four degrees celsius and, in some areas, seven times faster than the rest of the planet. This process is named Arctic Amplification and occurs in the Arctic ocean and on land.
The consequences of the heating Arctic are becoming evident in the world's weather, particularly the Northern Hemispheres weather. Heat waves, drought, wildfires, and flooding news is so alarming that even mainstream media has paid attention. Most do not connect the dots to greenhouse gas emissions, but scientists do if they join in the discussion. The polar region is our planet's air-conditioner and is rapidly breaking down, leaving us to heat up like a frog in a pot.
In another sign of deglaciation, a study has found that retrogressive slump thaws in Siberia's Taymyr peninsula reveal a substantial "43-fold increase in retrogressive thaw slump activity and a 28-fold increase in carbon mobilization."
Marianne Lucien, ETH Zurich writes in Phys.org
Siberia's Taymyr peninsula, like many areas of the Arctic, is a remote and nearly inaccessible region making scientific field studies a challenging, if not impossible, operation. The findings of this study indicate, however, that summer heatwaves and warming arctic areas pose a significant environmental risk that is worth monitoring.
The Arctic permafrost reportedly encases approximately 1.5 trillion metric tons of organic carbon, about twice as much as currently contained in the atmosphere. Bernhard agrees that the potential risks associated with this type of carbon mobilization is "a major, but largely neglected component of the Arctic carbon cycle." The research team anticipates that satellite remote sensing will be an indispensable tool for continuous monitoring of carbon mobilization resulting from melting permafrost across the Arctic.
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Their findings, recently published in the European Geosciences Union journal The Cryosphere, reveal substantial changes to the topography of Siberia's Taymyr peninsula, in northern Russia. The study's results reveal a strong, 43-fold increase in retrogressive thaw slump activity and a 28-fold increase in carbon mobilization. The increase also happens to coincide with an extreme heat wave that occurred in northern Siberia in 2020 in which temperatures reportedly reached 38 degrees Celsius (more than 100 degrees Fahrenheit)—record-breaking temperatures for the Arctic region.
"The strong increase in thaw slump activity due to the Siberian heatwave shows that carbon mobilization from permafrost soils can respond sharply and non-linearly to increasing temperatures," asserts the paper's lead author, Philipp Bernhard, Institute of Environmental Engineering, ETH Zurich.
Dr. Zack Labbe reviews the state of the Arctic so far in 2022. He writes in Polar Bears and the Changing Arctic.
Although the long-term trends are clear in the Arctic—such as declining Arctic sea ice, warming ocean and atmospheric temperatures, melting glaciers, thawing permafrost, shifts in plant phenology and Arctic greening—there is also large year-to-year variability. This means that not every year will observe a new record. An excellent blog by Dr. Ed Hawkins described this type of sea-ice variability as analogous to that of a bouncing ball rolling down a hill. While the downward movement of the ball is inevitable, there are still periods of upwards bounces.
In the real-world, this variability is tied to the chaotic nature of our atmosphere (often called “internal variability” and similar to the concept of the butterfly effect). This characteristic is well simulated by our climate models and is considered when analyzing future climate change projections. This is one reason that it is nearly impossible to predict the exact timing of our first ice-free Arctic summer. So far, 2022 fits this example perfectly. While we’ve witnessed sea-ice levels consistent with the long-term declining trend, there have been no new monthly records yet this year.
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Compared to some recent years, the last few months have observed fairly small temperature departures across the greater Arctic Ocean basin (Figure 2). Cooler temperatures have generally been found around northern Greenland and stretching to the North Pole, while anomalous warmth has been confined to the Siberian coastal region around the Kara and Laptev Seas. These patterns of warmer and colder temperatures are linked to the position and strength of the jet stream and regions of low sea-ice cover.
Averaging temperatures over the last 12 months helps to remove some of the monthly variability from changes in weather patterns and subsequently reveals the familiar pattern of only warmer departures across nearly the entire Northern Hemisphere.
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The latest predictions from this network of forecasts do not suggest a new record low this year for the annual sea ice minimum in September. However, weather forecast models indicate an acceleration of sea-ice melt conditions through at least mid-July over parts of the Canadian Arctic with temperatures rising to more than 15°C (27°F) above average. Satellite observations also confirm that melting is already well underway in the Beaufort Sea with large melt ponds visible overtop of the existing sea ice. The consequences of this warmer and drier weather are also being felt across surrounding land areas with extreme wildfires and poor air quality found in Alaska and northwestern Canada.
