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Environment Of Virginia
The natural environment of Virginia encompasses the physical geography and biology of the U.S. state of Virginia. Virginia has a total area of , including of water, making it the 35th- largest state by area. Forests cover 65% of the state, wetlands and water cover 6% of the land in the state, while 5% of the state is a mixture of commercial, residential, and transitional. Virginia is bordered by Maryland and Washington, D.C. to the north and east; by the Atlantic Ocean to the east; by North Carolina and Tennessee to the south; by Kentucky to the west; and by West Virginia to the north and west. Due to a peculiarity of Virginia's original charter, its boundary with Maryland and Washington, D.C. does not extend past the low-water mark of the south shore of the Potomac River (unlike many boundaries that split a river down the middle). The southern border is defined as the 36° 30′ parallel north, though surveyor error led to deviations of as much as three arcminutes. The sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Hollow Falls Shenandoah NP 2007
Darkness is the condition resulting from a lack of lighting, illumination, or an absence of visible light. Human visual perception, vision is unable to distinguish colors in conditions of very low luminance because the hue-sensitive photoreceptor cells on the retina are inactive when light levels are insufficient, in the range of visual perception referred to as scotopic vision. The emotional response to darkness has generated metaphorical usages of the term in many cultures, often used to describe an unhappy or foreboding feeling. "Darkness" may also refer to night, which occurs when the Sun is more than 18° below the horizon. Scientific Perception The perception of darkness differs from the mere absence of light that sometimes lead to afterimages. In perceiving, the eye is active, and the part of the retina that is unstimulated produces a complementary afterimage. Physics In terms of physics, an object is said to be dark when it absorbs photons, causing it to appear dim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Ecoregions In The United States (EPA)
This list provides an overview of United States ecoregions designated by the U.S. Environmental Protection Agency (EPA) and the Commission for Environmental Cooperation (CEC). The CEC was established in 1994 by the member states of Canada, Mexico, and the United States to address regional environmental concerns under the North American Agreement on Environmental Cooperation (NAAEC), the environmental side accord to the North American Free Trade Agreement (NAFTA). The Commission's 1997 report, ''Ecological Regions of North America'', provides a framework that may be used by government agencies, non-governmental organizations, and academic researchers as a basis for risk analysis, resource management, and environmental study of the continent's ecosystems. In the United States, the EPA and the United States Geological Survey (USGS) are the principal federal agencies working with the CEC to define and map ecoregions. Ecoregions may be identified by similarities in geology, physiog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
York River (Virginia)
The York River is a navigable estuary, approximately long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 1, 2011 in eastern Virginia in the United States. It ranges in width from at its head to near its mouth on the west side of Chesapeake Bay. Its watershed drains an area of the coastal plain of Virginia north and east of Richmond. Its banks were inhabited by indigenous peoples for thousands of years. In 2003 evidence was found of the likely site of Werowocomoco, one of two capitals used by the paramount chief Powhatan before 1609. The site was inhabited since 1200 as a major village. Enormously important in later U.S. history, the river was also the scene of early settlements of the Virginia Colony. It was the site of significant events and battles in both the American Revolutionary War and the American Civil War. Description The York River is formed at West Point, approximately east of Richmond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James River
The James River is a river in Virginia that begins in the Appalachian Mountains and flows from the confluence of the Cowpasture and Jackson Rivers in Botetourt County U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 1, 2011 to the Chesapeake Bay. The river length extends to if the Jackson River (Virginia), Jackson River, the longer of its two headwaters, is included. It is the longest river in Virginia. Jamestown, Virginia, Jamestown and Williamsburg, Virginia, Williamsburg, Virginia's first colonial capitals, and Richmond, Virginia, Richmond, Virginia's current capital, lie on the James River. History The Native American tribes in Virginia, Native Americans who populated the area east of the Atlantic Seaboard Fall Line, Fall Line in the late 16th and early 17th centuries called the James River the Powhatan River, named for the Powhatan, Powhatans who occupied the area. The Jamestown, Virginia, Jamestown colo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rappahannock River
The Rappahannock River is a river in eastern Virginia, in the United States, approximately in length.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed April 1, 2011 It traverses the entire northern part of the state, from the Blue Ridge Mountains in the west where it rises, across the Piedmont to the Fall Line, and onward through the coastal plain to flow into the Chesapeake Bay, south of the Potomac River. An important river in American history, the Rappahannock was long an area of occupation by indigenous peoples, including the Rappahannock Tribe. Similarly, during the colonial era, early settlements in the Virginia Colony were formed along the river. During the American Civil War, due to the river's acting as a barrier to north–south troop movements, it effectively functioned as the boundary of the eastern theater of the war, between the "North" (the Union) and the "South" (the Confederate States of America). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Virginia Rivers
This is a list of rivers in the U.S. state of Virginia. By drainage basin This list is arranged by drainage basin, with respective tributaries, arranged in the order of their confluence from mouth to source, indented under each larger stream's name. Atlantic Ocean north of Chesapeake Bay * Cockle Creek * Machipongo River Chesapeake Bay *Pocomoke River *Potomac River ** Hull Creek ** Coan River ** Yeocomico River *** Northwest Yeocomico River *** South Yeocomico River *** West Yeocomico River ** Lower Machodoc Creek ** Nomini Creek ** Popes Creek ** Mattox Creek ** Rosier Creek ** Upper Machodoc Creek **Potomac Creek ***Accokeek Creek **Aquia Creek **Chopawamsic Creek **Quantico Creek **Neabsco Creek **Occoquan River *** Massey Creek *** Sandy Run ***Stillwell Run *** Bull Run **** Popes Head Creek **** Cub Run **** Little Bull Run **** Foley Branch *** Cedar Run *** Broad Run **** Kettle Run ** Pohick Creek **Accotink Creek ** Dogue Creek **Little Hunting Creek ** Hunting Creek * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior 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 planets and moons, based on data from U.S. space probes. The sole scientific agency of the U.S. Department of the Interior, USGS is a fact-finding research organization with no regulatory responsibility. It is headquartered in Reston, Virginia, with major offices near Lakewood, Colorado; at the Denver Federal Center; and in NASA Research Park in California. In 2009, it employed about 8,670 people. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on its hundredth anniversary, was "Earth Science in the Pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''Ēṓs'', 'Eos, Dawn') and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chesapeake Bay Impact Crater
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. Continued slumping of sediments over the rubble of the crater has helped shape the Chesapeake Bay. Formation and aftermath During the warm late Eocene, sea levels were high, and the tidewater region of Virginia lay in the coastal shallows. The shore of eastern North America, about where Richmond, Virginia is today, was covered with thick tropical rainforest, and the waters of the gently sloping continental shelf were rich with marine life that was depositing dense layers of lime from their microscopic shells. The bolide made impact at a speed of approximately , punching a deep hole through the sediments and into the granite continental basement rock ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Shore Of Virginia
The Eastern Shore of Virginia is the easternmost region of the Commonwealth (U.S. state), Commonwealth of Virginia in the United States. It consists of two counties (Accomack County, Virginia, Accomack and Northampton County, Virginia, Northampton) on the Atlantic coast. It is detached from the mainland of Virginia by the Chesapeake Bay. The region is part of the Delmarva Peninsula. Its population was 45,695 as of 2020. History Accomac Shire was established in the Virginia Colony by the House of Burgesses in 1634 under the direction of King Charles I of England, Charles I. It was one of the original eight shires of Virginia, and consisted of the whole of Virginia's Delmarva territory. The shire's name comes from the Native American word Accawmack, which means, "the other shore". In 1642, the name was changed to Northampton County, Virginia, Northampton County. (In England, "shires" and "counties" are the same thing.) In 1663, Northampton County was split into two counties. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chesapeake Bay
The Chesapeake Bay ( ) is the largest estuary in the United States. The bay is located in the Mid-Atlantic (United States), 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 (headland), 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 drainage basin, which covers parts of six states (New York (state), New York, Pennsylvania, Delaware, Maryland, Virginia, and West Virginia) and all of Washington, D.C. The bay is approximately long from its northern headwaters in the Susquehanna River to its outlet i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estuary
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
