How deep is the ocean? – the Conversation

Mother humpback and calf (courtesy of NOAA Photo Library CC BY 2.0 via Flickr).

If you wanted to measure the depth of a pool or lake, you could tie a weight to a string, lower it to the bottom, then pull it up and measure the wet part of the string. In the ocean you would need a rope thousands of feet long. In 1872 the HMS Challenger, a British Navy ship, set sail to learn about the ocean, including its depth. It carried 181 miles (291 kilometers) of rope…

The “Octopus Garden” – MBARI

Pearl octopus (Muusoctopus robustus) nesting in rocky crevices in the "Octopus Garden" on the Davidson Seamount, part of the Monterey Bay Marine Sanctuary off the central coast of California. (courtesy of Ocean Exploration Trust / NOAA, public domain).

Deep below the ocean’s surface just off the Central California coast, thousands of octopus gather near an extinct underwater volcano. The Octopus Garden is the largest known aggregation of octopus anywhere in the world…

A sea change on managed retreat? – CommonWealth Journal

Plum Island, Merrimack River entrance, 40 minutes after high tide, January 23, 2023 (courtesy of Massachusetts the Office of Coastal Management via mycoast.org/ma).

As waters rise, coastal residents are increasingly facing a difficult choice: try to relocate in a difficult housing market and take losses on their homes, or get comfortable with a future where there may be multiple feet of water in their living rooms…

Where does beach sand come from? – the Conversation

Pebbles on the Beach (by Susanne Nilsson CC BY-SA 2.0 via Flickr).

Question from Sly M., age 6, Cambridge, Massachusetts…
There’s more to beach sand than meets the eye. It has stories to tell about the land, and an epic journey to the sea. That’s because mountains end their lives as sand on beaches….