Aboard the Swedish Icebreaker (IB) Oden, the Ryder 2019 Expedition, which the ExplorersClub officially designated as “Flag Expedition #51,” we successfully achieved our ambitious goals of scientifically investigating northern Greenland and creating the first ever maps of water depths in the ice-infested seas of the usually inaccessible and essentially unexplored Sherard Osborn Fjord, which connects the southern Lincoln Sea and the northern Nares Strait to the Ryder Glacier, one of the primary outlet glaciers draining the Greenland Ice Sheet.The expedition departed from the harbor of US Air Force Base Thule on August 5, 2019, and returned there on September 10th. During those 37 days, the international scientific party of 39 scientists, assisted by seven representatives from the Swedish Polar Research Secretariat, and 26 crew members, travelled 3369 nautical miles achieving all of their high-priority research goals on land and sea. One of the primary accomplishments was creating the first-ever, high-quality bathymetric map of large areas of previously uncharted waters. IB Oden was the first vessel (after Greenlandic Inuit in kayaks, of course) to enter these waters, and to reveal the fascinating and complicated shape of the seafloor that shows geological structuresand evidence of the powerful forces of the Greenland Ice Sheet and its marine outlet glaciers as they advanced and retreated during past glaciations. The map shows that the near vertical fjord walls, roughly 1 km high, continue downward, below sea level, with equal steepness, and nearly equal depths, as great as 900 meters in Sherard Osborn Fjord. The new map also shows the specific pathways by which warmer subsurface waters of Atlantic origin reach into the fjords of northern Greenland, where they come into contact with the floating glacial ice tongues and impact the rate at which the ice melts. The warmer waters have first circulated through the Arctic Ocean and into the Lincoln Sea, before reaching the fjord mouths. Another major achievement of the expedition was collecting many types of data that reveal dramatic environmental changes, over a variety of timescales, of the frozen world (cryosphere, which consists of ice sheets, marine outlet glaciers, and their floating icetongues, and sea ice) and how it waxes and wanes, in response to climate change, and, conversely, also contributing to it. Revealing the history of the cryosphere, and the mechanismsby which it changes, provides information that is essential to understanding Greenland’s modern cryosphere, which has global significance with respect to climate, because the ice sheet holds water equivalent to a global sea-level rise by over 7 meters.

The broad scientific program included marine geology, geophysics and marine chemistry, biology, ecology, glaciology, oceanography, climatology, air chemistry, and archeology. Data processing began immediately onboard IB Oden in the permanent and temporary laboratories setup specifically for the expedition in portable containers. As opportunities to explore remote, generally inaccessible regions are rare, teams of scientists who conduct research on land joined the expedition, making it truly multidisciplinary. They journeyed back and forth to the ship by two helicopters on IB Oden’s helipad either on day trips, or for a week at a time, by camping on lands nearby the fjord. By taking samples of driftwood from the shoreline, clam shells from elevated terraces, and by studying modern and ancient remains of plant and animals, and artifacts left behind by ancient peoples, these teams will reconstruct sea-level history, ice sheet thickness, climate change, and the colonization history of Greenland, after the last ice age, by humans, animals and plants, and how they have shaped the environment of what we now find in Greenland.