In a process that played out over thousands of years, a retreating ice sheet carved, scoured and shaped the landscape of the present-day Great Lakes. In northern Lake Michigan, this sculpting left distinct ridges and valleys running north-to-south along the lake floor. Some parts of those ridges, made of erosion-resistant rock, have remained above the waves of the big lake, forming the Beaver Archipelago.
The OLI (Operational Land Imager) on Landsat 9 captured this image of several of the archipelago’s islands on Aug. 2, 2024. These patches of land contain upland forests, dunes, wetlands and marshes—habitats that support rare plant and bird species and provide spawning grounds for fish. The bright, sandy perimeters of the islands are surrounded by shallow, turquoise waters and deeper, dark-blue areas, where depths reach up to about 330 feet (100 meters).
This image centers on Beaver Island, the largest island in Lake Michigan at 13 miles (21 kilometers) long and 6 miles (10 kilometers) wide. It is also the only inhabited island of the Beaver Archipelago, and many of its approximately 600 residents are of Irish descent. In the mid-1800s, scores of immigrants from County Donegal, Ireland, and Irish fishermen from nearby islands and ports in Michigan settled on the island, which subsequently took on the moniker of “America’s Emerald Isle.”
Image Credit: NASA Earth Observatory image by Wanmei Liang, using Landsat data from the U.S. Geological Survey.
