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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 stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dark Hollow Falls Shenandoah NP 2007
Darkness, the direct opposite of lightness, is defined as a lack of lighting, illumination, an absence of visible spectrum, visible light, or a surface that absorbs light, such as black or brown. Human visual perception, vision is unable to distinguish colors in conditions of very low luminance. This is 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. Referring to a time of day, night, complete darkness occurs when the Sun is more than 18° below the horizon, without the effects of twilight on the night sky. Scientific Perception The perception of darkness differs from the mere absence of light due to the effects of afterimage, after images on perception. In perceiving, the eye is active, and the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Ecoregions In The United States (EPA)
This list of ecoregions in the United States 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 ... [...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 Atlantic coastal plain, coastal plain of Virginia north and east of Richmond, Virginia, Richmond. Its banks were inhabited by indigenous peoples of North America, 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 Colony of Virginia, Virginia Colony. It was the site of significant events and battles in both the American Revolutionary War and the American C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James River
The James River is a river in the U.S. state of Virginia that begins in the Appalachian Mountains and flows U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map , accessed April 1, 2011 to Chesapeake Bay. The river length extends to if one includes the Jackson River, the longer of its two source tributaries. It is the longest river in Virginia. Jamestown and Williamsburg, Virginia's first colonial capitals, and Richmond, Virginia's current capital, lie on the James River. History The Native Americans who populated the area east of the Fall Line in the late 16th and early 17th centuries called the James River the Powhatan River, named for the chief of the Powhatan Confederacy which extended over most of the Tidewater region of Virginia. The Jamestown colonists who arrived in 1607 named it "James" after King James I of England (), as they constructed the first permanent English settlement in the Americas at Jamestown along t ... [...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. 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). It was at the center of a major theater o ... [...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 (Virginia), Cockle Creek *Machipongo River Chesapeake Bay *Pocomoke River *Potomac River **Hull Creek (Potomac River tributary), Hull Creek **Coan River **Yeocomico River ***Northwest Yeocomico River ***South Yeocomico River ***West Yeocomico River **Lower Machodoc Creek **Nomini Creek **Popes Creek (Virginia), Popes Creek **Mattox Creek **Rosier Creek **Upper Machodoc Creek **Potomac Creek ***Accokeek Creek **Aquia Creek **Chopawamsic Creek **Quantico Creek **Neabsco Creek **Occoquan River ***Bull Run (Occoquan River tributary), Bull Run ****Popes Head Creek ****Cub Run ****Little Bull Run ***Cedar Run (Occoquan River tributary), Cedar Run ***Broad Run (Occoquan River tributary), B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). 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'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. 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 isotope Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Popigai impact structure, Siberia and in what is now ... [...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 per second, punching a deep hole through the sediments and into the granite continental base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Shore Of Virginia
The Eastern Shore of Virginia consists of two counties ( Accomack and Northampton) on the Atlantic coast detached from the mainland of the Commonwealth of Virginia in the United States. The region is part of the Delmarva Peninsula and is separated from the rest of Virginia by the Chesapeake Bay. Its population was 45,695 as of 2020. The terrain is overall very flat, ranging from sea level to just above sea level. It is characterized by sandy and deep soil. The weather in the area has temperate summers and winters, significantly affected by the Chesapeake Bay and the Atlantic Ocean."Virginia's Eastern Shore (AVA): Appellation Description" ''Appellation America'', 2007, Retrieved Jan. 31, 2008 The rural area has long been devoted to |
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 the parts: the Eastern Shore of Maryland / Eastern Shore of Virginia and the state of Delaware) with its mouth of the Bay at the south end 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, Pennsylvania, Delaware, Maryland, Virginia and West Virginia) and all of District of Columbia. The Bay is approximately long from its northern headwaters in the Susquehanna River to its outlet in the Atlantic Ocea ... [...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 bays, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
