Hudson Bay Is Missing Gravity — Satellites Showed the Ice Age Explains Less Than Half of It

Stand on the shore at Churchill, Manitoba, and the sea is leaving the land. Relative sea level there keeps falling, and a tide gauge records it, because the ground is rising faster than the ocean. What is lifting the ground, and why does gravity over Hudson Bay pull slightly less than a smooth planet would give? The video walks through thirty facts about the bay, from its size and its rivers to the Laurentide ice sheet that once covered it. It follows the stranded beaches that stand high above today's waves, the coastline that is still climbing, and the Halifax coast on the other side of the same Ice Age. Then it turns to the twin GRACE satellites that weighed the ground from orbit, and to the scientists who tried to explain the gravity anomaly. The list ends with the two suspects still on the table and with what the measurements can and cannot yet separate. Sources: Harvard-Smithsonian Center for Astrophysics — Rebounding from the Ice Age: https://cfa.harvard.edu/news/reboundi... California Institute of Technology (Caltech) — Geophysicists Develop Model to Describe Huge Gravity Anomaly in Hudson Bay Region: https://lindecenter.caltech.edu/news/... NASA Earth Observatory — Rebounding in Hudson Bay: https://science.nasa.gov/earth/earth-... NASA Jet Propulsion Laboratory (JPL) — Prolific Earth Gravity Satellites End Science Mission: https://www.jpl.nasa.gov/news/prolifi... Natural Resources Canada / Environment and Climate Change Canada — Canada's Changing Climate Report - Chapter 7: Changes in Oceans Surrounding Canada: https://changingclimate.ca/CCCR2019/c...