NASA’s latest image of Boston Harbor has revealed a rare geological formation – the drumlin islands, shaped by glaciers over 20,000 years ago. The Landsat 8 Operational Land Imager captured this striking visual as part of a detailed study shared by the NASA Earth Observatory.
The drumlin islands are a geological treasure formed during the Wisconsin Glaciation period, when massive glaciers up to a mile thick covered the land that now forms the Boston Harbor Islands National and State Park. As the glaciers retreated, they left behind piles of sediment and debris, forming these distinctive elongated hills.
Boston Harbor’s unique drumlins are partially submerged, making them a rare sight in North America. Scientists believe rising sea levels transformed these once-formed hills into islands, while glacial movements were dynamic and unpredictable.
The islands hold historical significance, with four accessible by car and others by ferry or boat. They’re part of the Boston Harbor Islands National and State Park, which preserves unique history and natural beauty.
Beyond their geological value, the drumlin islands support diverse ecosystems and marine life. Scientists study these islands to understand how climate change might impact fragile ecosystems, including salt marshes and tidal pools. As sea levels continue to rise, these habitats are vulnerable to erosion, making the drumlins a key site for studying long-term coastal environment impacts.
Source: https://dailygalaxy.com/2025/04/nasa-image-geologic-wonders-boston-harbor