America’s Emerald Isle

Earth Observatory Science Earth Observatory America’s Emerald Isle Earth Earth Observatory Image of the Day EO Explorer Topics All Topics Atmosphere Land Heat & Radiation Life on Earth Human Dimensions Natural Events Oceans Remote Sensing Technology Snow & Ice Water More Content Collections Global Maps World of Change Articles Notes from the Field Blog Earth Matters Blog Blue Marble: Next Generation EO Kids Mission: Biomes About About Us Subscribe 🛜 RSS Contact Us Search 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 August 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.” The farming and fishing, in particular, were productive for the new arrivals. In the 1880s, Beaver Island became the largest supplier of freshwater fi