Geography

Main article: Environment of Virginia

Geographically and geologically, Virginia is divided into five regions from east to west: Tidewater, Piedmont, Blue Ridge Mountains, Ridge and Valley, and Cumberland Plateau.^[18]

Virginia has a total area of 42,774.2 square miles (110,784.7 km²), including 3,180.13 square miles (8,236.5 km²) of water, making it the 35th-largest state by area.^[19] Virginia is bordered by Maryland and Washington, D.C. to the north and east; by the Atlantic Ocean to the east; by North Carolina to the south; by Tennessee to the southwest; by Kentucky to the west; and by West Virginia to the north and west. Virginia's boundary with Maryland and Washington, D.C. extends to the low-water mark of the south shore of the Potomac River.^[20] The southern border is defined as the 36° 30′ parallel north, though surveyor error led to deviations of as much as three arcminutes.^[21] The border with Tennessee was not settled until 1893, when their dispute was brought to the U.S. Supreme Court.^[22]

Geology and terrain

The Chesapeake Bay separates the contiguous portion of the Commonwealth from the two-county peninsula of Virginia's Eastern Shore. The bay was formed from the drowned river valleys of the Susquehanna River and the James River.^[23] Many of Virginia's rivers flow into the Chesapeake Bay, including the Potomac, Rappahannock, York, and James, which create three peninsulas in the bay.^[24][25]

Deciduous and evergreen trees give the Blue Ridge Mountains their distinct color.^[26]

The Tidewater is a coastal plain between the Atlantic coast and the fall line. It includes the Eastern Shore and major estuaries of Chesapeake Bay. The Piedmont is a series of sedimentary and igneous rock-based foothills east of the mountains which were formed in the Mesozoic era.^[27] The region, known for its heavy clay soil, includes the Southwest Mountains around Charlottesville.^[28] The Blue Ridge Mountains are a physiographic province of the Appalachian Mountains with the highest points in the state, the tallest being Mount Rogers at 5,729 feet (1,746 m).^[29] The Ridge and Valley region is west of the mountains and includes the Great Appalachian Valley. The region is carbonate rock based and includes Massanutten Mountain.^[30] The Cumberland Plateau and the Cumberland Mountains are in the southwest corner of Virginia, south of the Allegheny Plateau. In this region, rivers flow northwest, with a dendritic drainage system, into the Ohio River basin.^[31]
The Virginia Seismic Zone has not had a history of regular earthquake activity. Earthquakes are rarely above 4.5 in magnitude, because Virginia is located away from the edges of the North American Plate. The largest earthquake, at an estimated 5.9 magnitude, was in 1897 near Blacksburg.^[32] A 5.8 magnitude earthquake struck central Virginia on August 23, 2011, near Mineral. The earthquake was reportedly felt as far away as Toronto, Atlanta and Florida.^[33]
Coal mining takes place in the three mountainous regions at 45 distinct coal beds near Mesozoic basins.^[34] Over 62 million tons of other non-fuel resources, such as slate, kyanite, sand, or gravel, were also mined in Virginia in 2012.^[35] The state's carbonate rock is filled with more than 4,000 caves, ten of which are open for tourism.^[36] 35 million years ago, a bolide impacted what is now eastern Virginia. The resulting crater may explain sinking and earthquakes in the region.^[37]

Climate

Main article: Climate of Virginia

Virginia state-wide averages
Climate chart (explanation)
J F M A M J J A S O N D     3.1     46 26     3.1     48 27     3.7     57 34     3.3     67 43     4     76 52     3.7     83 60     4.3     86 64     4.1     85 63     3.5     79 57     3.4     69 45     3.2     58 35     3.2     48 28 Average max. and min. temperatures in °F Precipitation totals in inches Source: University of Virginia data 1895–1998
[show]Metric conversion

The climate of Virginia is temperate and becomes increasingly warmer and more humid farther south and east.^[38] Seasonal extremes vary from average lows of 26 °F (−3 °C) in January to average highs of 86 °F (30 °C) in July. The Atlantic Ocean has a strong effect on eastern and southeastern coastal areas of the state. Influenced by the Gulf Stream, coastal weather is subject to hurricanes, most pronouncedly near the mouth of Chesapeake Bay.^[39] In spite of its position adjacent to the Atlantic Ocean, even the coastal areas have a significant continental influence with quite large temperature differences between summer and winter, particularly given the state climate's subtropical classification, which is typical of states in the Upper South.
Virginia has an annual average of 35–45 days of thunderstorm activity, particularly in the western part of the state,^[40] and an average annual precipitation of 42.7 inches (108 cm).^[39] Cold air masses arriving over the mountains in winter can lead to significant snowfalls, such as the Blizzard of 1996 and winter storms of 2009–2010. The interaction of these elements with the state's topography creates distinct microclimates in the Shenandoah Valley, the mountainous southwest, and the coastal plains.^[41] Virginia averages seven tornadoes annually, most F2 or lower on the Fujita scale.^[42]
In recent years, the expansion of the southern suburbs of Washington, D.C. into Northern Virginia has introduced an urban heat island primarily caused by increased absorption of solar radiation in more densely populated areas.^[43] In the American Lung Association's 2011 report, 11 counties received failing grades for air quality, with Fairfax County having the worst in the state, due to automobile pollution.^[44][45] Haze in the mountains is caused in part by coal power plants.^[46]

Ecosystem

Forests cover 65% of the state, primarily with deciduous, broad leaf trees in the western part of the state and evergreens and conifers dominant the central and eastern part of Virginia.^[47] Lower altitudes are more likely to have small but dense stands of moisture-loving hemlocks and mosses in abundance, with hickory and oak in the Blue Ridge.^[38] However, since the early 1990s, Gypsy moth infestations have eroded the dominance of oak forests.^[48] In the lowland tidewater and piedmont, yellow pines tend to dominate, with bald cypress wetland forests in the Great Dismal and Nottoway swamps. Other common trees and plants include red bay, wax myrtle, dwarf palmetto, tulip poplar, mountain laurel, milkweed, daisies, and many species of ferns. The largest areas of wilderness are along the Atlantic coast and in the western mountains, where the largest populations of trillium wildflowers in North America are found.^[38][49] The Atlantic coast regions are host to flora commonly associated with the South Atlantic pine forests and lower Southeast Coastal Plain maritime flora, the latter found primarily in eastern and central Virginia.

White-tailed deer, also known as Virginia deer, graze at Big Meadows in Shenandoah National Park

Mammals include white-tailed deer, black bear, beaver, bobcat, coyote, raccoon, skunk, groundhog, Virginia opossum, gray fox, red fox, and eastern cottontail rabbit.^[50] Other mammals include: nutria, fox squirrel, gray squirrel, flying squirrel, chipmunk, brown bat, and weasel. Birds include cardinals (the state bird), barred owls, Carolina chickadees, red-tailed hawks, ospreys, brown pelicans, quail, seagulls, bald eagles, and wild turkeys. Virginia is also home to the pileated woodpecker as well as the red-bellied woodpecker. The peregrine falcon was reintroduced into Shenandoah National Park in the mid-1990s.^[51] Walleye, brook trout, Roanoke bass, and blue catfish are among the 210 known species of freshwater fish.^[52] Running brooks with rocky bottoms are often inhabited by plentiful amounts of crayfish and salamanders.^[38] The Chesapeake Bay is host to many species, including blue crabs, clams, oysters, and rockfish (also known as striped bass).^[53]
Virginia has 30 National Park Service units, such as Great Falls Park and the Appalachian Trail, and one national park, the Shenandoah National Park.^[54] Shenandoah was established in 1935 and encompasses the scenic Skyline Drive. Almost 40% of the park's area (79,579 acres/322 km²) has been designated as wilderness under the National Wilderness Preservation System.^[55] Additionally, there are 34 Virginia state parks and 17 state forests, run by the Department of Conservation and Recreation and the Department of Forestry.^[47][56] The Chesapeake Bay, while not a national park, is protected by both state and federal legislation, and the jointly run Chesapeake Bay Program which conducts restoration on the bay and its watershed. The Great Dismal Swamp National Wildlife Refuge extends into North Carolina, as does the Back Bay National Wildlife Refuge, which marks the beginning of the Outer Banks.^[57]