In 1810, in the Greenland Sea, William Scoresby Jr., the captain of Resolute, who was 21 years old, used an oceanographic instrument made from a ten-gallon wooden cask. It was built following Sir Joseph Banks’s instructions—he had sailed with Captain Cook, who also served as President of the Royal Society for 40 years.
The cask was made of two-inch-thick fir planks, “as being a bad conductor of heat.” At each end of the cask was a valve connected by a wire that opened and closed at the same time—a horizontal lever with a flat circular paddle extended from the barrel. When lowered, the lever was pushed upward, opening the valves and allowing seawater to flow through the barrel. When the hydrowinch was braked and the barrel stopped descending, its gravity caused the valves to close. The paddle lever kept the barrel sealed as it was reeled up from the ocean depths.
Scoresby first deployed the fir-cast on April 19, 1810. The Resolute was described in the data table as a “ship beset in ice.” They were in the Greenland Sea, west-southwest of Svalbard at Latitude 76.10′ North and Longitude 9.0′ East. The conventional wisdom was, and remains for many today, that the ocean is like a big bathtub where the temperature you feel with your toe correlates to the temperature down in the water column. If anything, the water would become colder with depth due to increasing distance from the surface and increasing density with rising pressure from the column of water above.
Preparing to lower the fir-cask, Scoresby’s crew noted that the surface ocean water was blue and 28.8 degrees F. The cask was lowered to a depth of 300 feet, where water was trapped, then raised and brought back onboard. The water was surprisingly 31.8 degrees. A deeper sounding, to 738 feet, showed seawater at 33.8 degrees. Finally, from a depth of 1,380 feet, the seawater measured 33.3 degrees. The water below the cold surface waters was warmer.
Initially, they blamed the ordinary thermometer inserted into the cask on the deck. Later, a minimum-maximum thermometer was installed inside the cask behind a glass pane to avoid disturbing the contents when measuring the temperature. Water temperatures at different depths were measured multiple times from April to May 1810 and again in 1811, with similar results. Scoresby wrote in his journal:
From the fact of the sea near Spitsbergen being usually six or seven degrees warmer at the depth of 100 to 200 fathoms than it is at the surface, it seems not improbable that the water below is a still farther extension of the Gulf Stream, which, on meeting with water near the ice lighter than itself, sinks below the surface, and become a counter under-current. (William Scoresby, page 209.)
The ship Resolution was close to directly over the deep suture fault line where the North American plate diverges from Europe. Scoresby was making observations in Fram Strait, the only deep-water connection between the Arctic Ocean and the World Ocean. The fir-cask was capturing warm water transported North by the Gulf Stream. The Gulf Stream warmed Scotland’s Western shores, permitting palm trees to grow. Across the Atlantic, North American shores are chilled by the cold Labrador Current, transporting ice from Baffin Bay and Greenland. Scoresby noted: “a body of about 2000 square leagues of ice, having drifted out of the Greenland Sea.”
Scoresby was also concerned with climate change, writing: “changes of climate to a certain extent, have occurred, within the limits of historical record; these changes have been… considered as the effects of human industry, in draining marshes and lakes, felling woods, and cultivating the earth.” (page 263)
Two hundred years later, the climate changed as the Gulf Stream strengthened. In 2007, warm Atlantic Gulf Stream water rose to the surface of the sea at Svalbard, warming the air and melting the glaciers on the islands.
By 2011, the Gulf Stream was observed meandering to dissipate energy onto the Continental Shelf closer to Rhode Island than ever before. NASA’s Arctic Sea Ice Minimum 2024 animated video shows the Arctic Ocean first melting where the Atlantic meets the Arctic and then moving counterclockwise along Siberia’s shore because of the Earth’s spin, which causes flowing water to turn to the right— the Coriolis effect.
Sea ice forms to cover the Arctic Ocean in October. Water freezes at a warmer temperature if it is fresh. As water solidifies, salt is extruded into the adjacent liquid. Scoresby reported: “With the degree of saltness common to the Greenland Sea, freezes at 28 ½. Seawater, concentrated by freezing, until it… requires a temperature of 13 2/3 for its congelation, having its freezing point reduced by 18 1/3 below that of pure water.” (page 231)
In 2005, researchers reported that in Svalbard, ice formation and brine rejection had created the highest bottom salinities observed in the last 20 years.5
The cold, briny water of the Arctic Ocean sinks and increases the flow of nutrient-rich Arctic water out of Fram Strait into the Atlantic Ocean. It jets through the Denmark Strait between Greenland and Iceland. Meeting warm nutrient-poor Atlantic water, it once dove 11,000 feet to flow below. With increased volume, the dive is not as deep. Further south, a cold-water temperature anomaly has developed, known as the cold blob.
Meanwhile, since Scoresby’s voyage, “the effects of human industry, in draining marshes and lakes, felling woods, and cultivating the earth” have accelerated the removal of vegetation and soils, and the loss of the carbon sponge, while increasing the extent of hard, impervious surfaces. Without increasing annual rainfall amounts, rainwater that once infiltrated the ground becomes destructive stormwater before crashing into the sea. We have strengthened the Gulf Stream with stormwater. It is transporting more water, warmed by our heat islands, northwards to melt Arctic sea ice and further change the climate.
The climate is further warmed when water-laden winds blow in from off the ocean onto coastal urban developments. These heat islands warm the air, causing it to expand and rise. Warmer air increases its humidity by drawing more moisture from the land. Globally, thirsty winds have pulled from the land more moisture than the volume of Lake Huron.
More water vapor in the atmosphere results in this greenhouse gas holding more heat energy, further warming the climate. Researchers reported that of the 1.5 degrees Celsius temperature increase the world has experienced, 1.2 degrees, or 80%, was due to more water vapor. In comparison, 0.2 degrees, or 10%, was attributed to the rising carbon dioxide levels. In the title and abstract, the publication obscured the significance of the findings by referring to water vapor as a greenhouse gas, which accounts for a major portion of the warming, and the 0.2 degrees was described in research as a “gap never satisfactorily explained.”
Increasing soil moisture is eight times more effective at reducing climate change than cutting carbon dioxide emissions. If we could increase vegetation and soils to hold more moisture in the ground, rather than in the air, the Earth would avoid the adverse effects of 420 parts per million of carbon. Naturally, with enhanced photosynthesis and a more active water cycle, life would also help lower the carbon level.
The lesson of Scoresby’s ten-gallon fir-cask is that if you want to understand how the world works, it’s best to venture out with a hardy crew and practice the real science of observation, recording, questioning, and communicating. Look deep below the surface, and when the data defies one’s beliefs, let go of the prevailing dogma and figure out what the data is telling you. And we’ll all be glad you did.
About the Author
Dr. Rob Moir is a nationally recognized and award-winning environmentalist. He is the president and executive director of the Ocean River Institute, a nonprofit based in Cambridge, MA, that provides expertise, services, resources, and information not readily available on a localized level to support the efforts of environmental organizations. Please visit www.oceanriver.org for more information