(Return matching records with ALLANY of these words.)    ................................................................ state Choose State Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Hawaii Idaho Illiniois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississipi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virginia Washington West Virginia Wisconsin Wyoming District of Columbia    regions Choose region Pacific Southwest Midwest Southeast Northeast Mountain-Prairie Alaska California-Nevada All Regions    ................................................................ ................................................................ Journal Entry   Back Landslide Northeast Region, May 6, 2005 Print Friendly Version Landslide at Rachel Carson NWR. Damage to Carson Trail. Blocked Merriland River pools and reroutes. A landslide on or about May 6, 2005 has changed the face of the Rachel Carson Trail near lookout No. 1. This event occurred as the result of three factors affecting banks of the Merriland River: a winding river channel, unconsolidated sediments and a high groundwater table combined to set in motion an event that has altered the landscape for hundreds of years. The current along the outside edge of the Merriland River channel steadily removed sediment from the base of the cliff over a period of many years. The river is tidal and flow is reversed twice a day. Steep, unstable riverbank cliffs made up of heavy sediments, not bedrock, added to the unpredictability of the area. Cliff sediments were composed of a sand layer and deeper marine clay layer that lacked any real cohesion. Lastly, high water tables, prevalent in the spring, kept the pore space (spaces between grains) in sediments saturated. This weakened the bond between particles; increased pressure from penetrating rainfall forced the soil apart and created greater instability. These combined factors; sediment type bank, river channel meandering and high water table caused a shift along a "plane of failure," or fault, which created a domino effect of opening additional cracks. Underlying clay then extruded sideways into the river while the sand, soil and trees dropped straight down, in some areas settling 20 feet below the original bluff. A remaining question is how the course of the river and the existing marsh will be altered by the damming effect of the landslide as the tidal river patiently dredges new channels and seeks the path of least resistance to the open ocean Contact Info: Jennifer Lapis, (413) 253-8303, jennifer_lapis@fws.gov Send to: From: Notes: ..........................................................................................

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