The coast,also known as the coastline,shoreline or seashore,is defined as the area where land meets the ocean,or as a line that forms the boundary between the land and the coastline. Shores are influenced by the topography of the surrounding landscape,as well as by water induced erosion,such as waves. The geological composition of rock and soil dictates the type of shore which is created. The Earth has around 620,000 kilometres (390,000 mi) of coastline. Coasts are important zones in natural ecosystems,often home to a wide range of biodiversity. On land,they harbor important ecosystems such as freshwater or estuarine wetlands,which are important for bird populations and other terrestrial animals. In wave-protected areas they harbor saltmarshes,mangroves or seagrasses,all of which can provide nursery habitat for finfish,shellfish,and other aquatic species. Rocky shores are usually found along exposed coasts and provide habitat for a wide range of sessile animals and various kinds of seaweeds. In physical oceanography,a shore is the wider fringe that is geologically modified by the action of the body of water past and present,while the beach is at the edge of the shore,representing the intertidal zone where there is one. Along tropical coasts with clear,nutrient-poor water,coral reefs can often be found between depths of 1–50 meters.
The Chesapeake Bay is the largest estuary in the United States. The Bay is located in the Mid-Atlantic region and is primarily separated from the Atlantic Ocean by the Delmarva Peninsula,including parts of the Eastern Shore of Maryland,the Eastern Shore of Virginia,and the state of Delaware. The mouth of the Bay at its southern point is located between Cape Henry and Cape Charles. With its northern portion in Maryland and the southern part in Virginia,the Chesapeake Bay is a very important feature for the ecology and economy of those two states,as well as others surrounding within its watershed. More than 150 major rivers and streams flow into the Bay's 64,299-square-mile (166,534 km2) drainage basin,which covers parts of six states,New York,Pennsylvania,Delaware,Maryland,Virginia,and West Virginia,and all of Washington,D.C.
Coastal erosion is the loss or displacement of land,or the long-term removal of sediment and rocks along the coastline due to the action of waves,currents,tides,wind-driven water,waterborne ice,or other impacts of storms. The landward retreat of the shoreline can be measured and described over a temporal scale of tides,seasons,and other short-term cyclic processes. Coastal erosion may be caused by hydraulic action,abrasion,impact and corrosion by wind and water,and other forces,natural or unnatural.
Longshore drift from longshore current is a geological process that consists of the transportation of sediments along a coast parallel to the shoreline,which is dependent on the angle of incoming wave direction. Oblique incoming wind squeezes water along the coast,and so generates a water current which moves parallel to the coast. Longshore drift is simply the sediment moved by the longshore current. This current and sediment movement occur within the surf zone. The process is also known as littoral drift.
Barrier islands are a coastal landform,a type of dune system and sand island,where an area of sand has been formed by wave and tidal action parallel to the mainland coast. They usually occur in chains,consisting of anything from a few islands to more than a dozen. They are subject to change during storms and other action,but absorb energy and protect the coastlines and create areas of protected waters where wetlands may flourish. A barrier chain may extend for hundreds of kilometers,with islands periodically separated by tidal inlets. The largest barrier island in the world is Padre Island of Texas,United States,at 113 miles (182 km) long. Sometimes an important inlet may close permanently,transforming an island into a peninsula,thus creating a barrier peninsula,often including a beach,barrier beach. Though many are long and narrow,the length and width of barriers and overall morphology of barrier coasts are related to parameters including tidal range,wave energy,sediment supply,sea-level trends,and basement controls. The amount of vegetation on the barrier has a large impact on the height and evolution of the island.
The Chesapeake Bay impact crater is a buried impact crater,located beneath the mouth of Chesapeake Bay,United States. It was formed by a bolide that struck the eastern shore of North America about 35.5 ±0.3 million years ago,in the late Eocene epoch. It is one of the best-preserved "wet-target" impact craters in the world.
A raised beach,coastal terrace, or perched coastline is a relatively flat,horizontal or gently inclined surface of marine origin,mostly an old abrasion platform which has been lifted out of the sphere of wave activity. Thus,it lies above or under the current sea level,depending on the time of its formation. It is bounded by a steeper ascending slope on the landward side and a steeper descending slope on the seaward side. Due to its generally flat shape,it is often used for anthropogenic structures such as settlements and infrastructure.
The Lamont–Doherty Earth Observatory (LDEO) is the scientific research center of the Columbia Climate School,and a unit of The Earth Institute at Columbia University. It focuses on climate and earth sciences and is located on a 189-acre campus in Palisades,New York,18 miles (29 km) north of Manhattan on the Hudson River.
In geology,a terrace is a step-like landform. A terrace consists of a flat or gently sloping geomorphic surface,called a tread,that is typically bounded on one side by a steeper ascending slope,which is called a "riser" or "scarp". The tread and the steeper descending slope together constitute the terrace. Terraces can also consist of a tread bounded on all sides by a descending riser or scarp. A narrow terrace is often called a bench.
Stephen Parker Leatherman,also known as Dr. Beach,is an American geoscientist,coastal ecologist,and author. He was the first director of the International Hurricane Research Center at Florida International University (FIU),from 1997 to 2009. He then became professor and co-director of the Laboratory for Coastal Research at FIU. Leatherman often discuss his research on beach quality evaluations,beach erosion,coastal storm and sea level rise impacts and rip currents.
Coastal engineering is a branch of civil engineering concerned with the specific demands posed by constructing at or near the coast,as well as the development of the coast itself.
The Virginia Institute of Marine Science (VIMS) is one of the largest marine research and education centers in the United States. Founded in 1940,VIMS is unique among marine science institutions in its legal mandate to provide research,education,and advisory services to government,citizens,and industry. Funding for VIMS comes from the Commonwealth of Virginia,grants and contracts from federal and state agencies,and private giving. The School of Marine Science (SMS) at VIMS is the graduate school in marine science for the College of William &Mary. VIMS offers M.S.,Ph.D.,and professional M.A. degrees in marine science. The school has 52 faculty members,an enrollment of 80-100 students,and includes 4 academic departments. VIMS' main campus is located in Gloucester Point,Virginia.
The United States Geological Survey (USGS),founded as the Geological Survey,is an agency of the United States government whose work spans the disciplines of biology,geography,geology,and hydrology. The agency was founded on March 3,1879,to study the landscape of the United States,its natural resources,and the natural hazards that threaten it. The agency also makes maps of extraterrestrial planets and moons based on data from U.S. space probes.
Leon County Pleistocene coastal terraces and shorelines were the geologic result of warming and cooling periods in what is now Leon County,Florida during the Pleistocene epoch.
Reginald Van Trump Truitt was an American zoologist,Army officer,and college lacrosse player and coach. He spent his professional career studying the oyster habitat in the Chesapeake Bay. Truitt founded the Chesapeake Biological Laboratory at what is now the University of Maryland Center for Environmental Science. He also served as the first head lacrosse coach at his alma mater,the University of Maryland from 1919 to 1927. Truitt was inducted into the National Lacrosse Hall of Fame in 1959.
Donald F. Boesch is a professor of marine science and,from 1990 to 2017,president of the University of Maryland Center for Environmental Science. From 2006-2017,he concurrently served as Vice Chancellor for Environmental Sustainability for the University System of Maryland. In 2010,he was appointed by President Barack Obama as a member of the National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling to investigate the root causes of the blowout at the Macondo Prospect in the Gulf of Mexico.
Dr. Mary A. Voytek is the director of the National Aeronautics and Space Administration (NASA) Astrobiology Program at NASA Headquarters in Washington, D.C. In 2015,Voytek formed Nexus for Exoplanet System Science (NExSS),a systems science initiative by NASA,to search for life on exoplanets. Voytek came to NASA from the U.S. Geological Survey in Reston,VA,where she headed the USGS Microbiology and Molecular Ecology Laboratory from 1998 to 2009.
The Nanjemoy Formation is a geologic formation pertaining to both the Wilcox Group and the Pamunkey Group of the eastern United States,stretching across the states of Virginia,Maryland,and District of Columbia. The formation crops out east of the Appalachians and dates back to the Paleogene period. Specifically to the Ypresian stage of the Eocene epoch,about 55 to 50 Ma or Wasatchian in the NALMA classification,defined by the contemporaneous Wasatch Formation of the Pacific US coast.
The geology of Virginia began to form 1.8 billion years ago and potentially even earlier. The oldest rocks in the state were metamorphosed during the Grenville orogeny,a mountain building event beginning 1.2 billion years ago in the Proterozoic,which obscured older rocks. Throughout the Proterozoic and Paleozoic,Virginia experienced igneous intrusions,carbonate and sandstone deposition,and a series of other mountain building events which defined the terrain of the inland parts of the state. The closing of the Iapetus Ocean,to form the supercontinent Pangaea added additional small landmasses,some of which are now hidden beneath thick Atlantic Coastal Plain sediments. The region subsequently experienced the rifting open of the Atlantic Ocean in the Mesozoic,the development of the Coastal Plain,isolated volcanism and a series of marine transgressions that flooded much of the area. Virginia has extensive coal,deposits of oil and natural gas,as well as deposits of other minerals and metals,including vermiculite,kyanite and uranium.
Jingpu "Paul" Liu is a geologist and professor at North Carolina State University.
