Misplaced Pages

#738261

90-678: Penns Valley is an eroded anticlinal valley of the Pennsylvania ridge and valley geologic region of the Appalachian Mountain range. The valley is located in southern Centre County, Pennsylvania . Along with the Nittany Valley to the north and east, it is part of the larger Nittany Anticlinorium. It is bordered by Mount Nittany to the north, the Seven Mountains range to the south, and connects to

180-517: A Pennsylvania State Senate bill for infrastructure improvement. There are two public airfields in Penns Valley. Centre Airpark is a sod 3,100 ft airstrip located approximately two miles south of Centre Hall. It is privately owned and is host to ultralight air shows during the summer months. Penns Cave Airport is an asphalt landing strip 4 miles east of Centre Hall and beside Penns Cave . The only private airfield in Penns Valley

270-429: A glacial armor . Ice can not only erode mountains but also protect them from erosion. Depending on glacier regime, even steep alpine lands can be preserved through time with the help of ice. Scientists have proved this theory by sampling eight summits of northwestern Svalbard using Be10 and Al26, showing that northwestern Svalbard transformed from a glacier-erosion state under relatively mild glacial maxima temperature, to

360-650: A book by Tom Shakely on the history of Mount Nittany and local conservation efforts, was published, incorporating histories of the mountain and valley. Mount Nittany is part of the Ridge and Valley province of the Appalachian Mountains . The neighboring Bald Eagle , Tussey and Shriner mountains are part of the same sedimentary formation, consisting of, from youngest to oldest, Tuscarora Formation quartzite , Juniata Formation shale , and Bald Eagle Formation sandstone . These layers were folded during

450-426: A considerable depth. A gully is distinguished from a rill based on a critical cross-sectional area of at least one square foot, i.e. the size of a channel that can no longer be erased via normal tillage operations. Extreme gully erosion can progress to formation of badlands . These form under conditions of high relief on easily eroded bedrock in climates favorable to erosion. Conditions or disturbances that limit

540-408: A fall in sea level, can produce a distinctive landform called a raised beach . Chemical erosion is the loss of matter in a landscape in the form of solutes . Chemical erosion is usually calculated from the solutes found in streams. Anders Rapp pioneered the study of chemical erosion in his work about Kärkevagge published in 1960. Formation of sinkholes and other features of karst topography

630-485: A glacier-armor state occupied by cold-based, protective ice during much colder glacial maxima temperatures as the Quaternary ice age progressed. These processes, combined with erosion and transport by the water network beneath the glacier, leave behind glacial landforms such as moraines , drumlins , ground moraine (till), glaciokarst , kames, kame deltas, moulins, and glacial erratics in their wake, typically at

720-464: A homogeneous bedrock erosion pattern, curved channel cross-section beneath the ice is created. Though the glacier continues to incise vertically, the shape of the channel beneath the ice eventually remain constant, reaching a U-shaped parabolic steady-state shape as we now see in glaciated valleys . Scientists also provide a numerical estimate of the time required for the ultimate formation of a steady-shaped U-shaped valley —approximately 100,000 years. In

810-423: A large river can remove enough sediments to produce a river anticline , as isostatic rebound raises rock beds unburdened by erosion of overlying beds. Shoreline erosion, which occurs on both exposed and sheltered coasts, primarily occurs through the action of currents and waves but sea level (tidal) change can also play a role. Hydraulic action takes place when the air in a joint is suddenly compressed by

900-492: A mountain mass similar to the Himalaya into an almost-flat peneplain if there are no significant sea-level changes . Erosion of mountains massifs can create a pattern of equally high summits called summit accordance . It has been argued that extension during post-orogenic collapse is a more effective mechanism of lowering the height of orogenic mountains than erosion. Examples of heavily eroded mountain ranges include

990-673: A steward of the Upper Penns Creek watershed . Its purview includes Penns Valley's waters, farmlands, forests, and rural heritage. PVCA also supports and organizes activities fostering local sourcing and environmental awareness. The Penns Valley Business Network brings together individuals and local businesses interested in professional advancement through the exchange of ideas and information amongst each other. The network joins 16 businesses, ranging from accounting and banking to landscaping and personal care management, in advancing these ideals. The Penns Valley Area School District

SECTION 10

#1732787080739

1080-501: A wave closing the entrance of the joint. This then cracks it. Wave pounding is when the sheer energy of the wave hitting the cliff or rock breaks pieces off. Abrasion or corrasion is caused by waves launching sea load at the cliff. It is the most effective and rapid form of shoreline erosion (not to be confused with corrosion ). Corrosion is the dissolving of rock by carbonic acid in sea water. Limestone cliffs are particularly vulnerable to this kind of erosion. Attrition

1170-412: A weak bedrock (containing material more erodible than the surrounding rocks) erosion pattern, on the contrary, the amount of over deepening is limited because ice velocities and erosion rates are reduced. Glaciers can also cause pieces of bedrock to crack off in the process of plucking. In ice thrusting, the glacier freezes to its bed, then as it surges forward, it moves large sheets of frozen sediment at

1260-488: Is deposited . Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as physical or mechanical erosion; this contrasts with chemical erosion, where soil or rock material is removed from an area by dissolution . Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall ; bedrock wear in rivers ; coastal erosion by

1350-467: Is PA 45 which runs through the heart of Penns Valley connecting all the townships and boroughs, except Miles Township served by PA 192. The only U.S. route in the area is US 322 which takes a unique form in Penns Valley as the smaller two-lane General Potter Highway linking the four-lane sections crossing the seven mountains and intersecting State College and Boalsburg. As of June 2013 plans have been proposed to increase this smaller section of US 322 through

1440-462: Is Pennfield Farm located just west of Spring Mills off PA Route 45. 40°51′N 77°37′W  /  40.850°N 77.617°W  / 40.850; -77.617 Eroded Erosion is the action of surface processes (such as water flow or wind ) that removes soil , rock , or dissolved material from one location on the Earth's crust and then transports it to another location where it

1530-686: Is a small, rural, public school district serving the southeastern portions of Centre County, Pennsylvania . It encompasses an area of 254.4 square miles (659 km2). Primary education is conducted in three K -4th grade elementary schools ; Centre Hall-Potter Township Elementary, Penns Valley Area Elementary, Rebersburg-Miles Township Elementary, and one district-wide combined 5th-6th grade Penns Valley Area Intermediate school operating concurrently with Penns Valley Area Elementary. The district's secondary educational needs are fulfilled by Penns Valley Junior-Senior High School which combines 7th through 12th grades. The district provides vocational education through

1620-428: Is a volunteer, Christian based, non-denominational, non-profit organization created for financially assisting members of the community effected by medical and accidental crises. The HOPE Fund has distributed over $ 250,000 from 2008 to 2013, and annually hosts many fundraising events throughout the area including festivals and banquets. The Penns Valley Conservation Association is a non-profit organization that acts as

1710-494: Is also more prone to mudslides, landslides, and other forms of gravitational erosion processes. Tectonic processes control rates and distributions of erosion at the Earth's surface. If the tectonic action causes part of the Earth's surface (e.g., a mountain range) to be raised or lowered relative to surrounding areas, this must necessarily change the gradient of the land surface. Because erosion rates are almost always sensitive to

1800-484: Is an example of extreme chemical erosion. Glaciers erode predominantly by three different processes: abrasion/scouring, plucking , and ice thrusting. In an abrasion process, debris in the basal ice scrapes along the bed, polishing and gouging the underlying rocks, similar to sandpaper on wood. Scientists have shown that, in addition to the role of temperature played in valley-deepening, other glaciological processes, such as erosion also control cross-valley variations. In

1890-533: Is created by Tussey Mountain which is one of the stratigraphic ridges of central Pennsylvania. Tussey Mountain is one of the longest running mountains of the Ridge and Valley complex starting in Flintstone, Maryland and running 80 miles into the Seven Mountains of central Pennsylvania. Egg Hill is a mountain separating greater Penns Valley from the subordinate Georges Valley. Rising to 1,955 ft., Egg Hill

SECTION 20

#1732787080739

1980-488: Is derived from the Algonquian word Nit-A-Nee meaning "single mountain". According to Penn State folklore, Nit-A-Nee is also the name of a Native American maiden whose actions caused Mount Nittany to be formed. The original inhabitants of the area used Nit-A-Nee to describe the mountain, and it likely became commonly known as "Nittany" by the first Europeans to settle the area in the 18th century. The word "Nittany"

2070-409: Is distinguished from changes on the bed of the watercourse, which is referred to as scour . Erosion and changes in the form of river banks may be measured by inserting metal rods into the bank and marking the position of the bank surface along the rods at different times. Thermal erosion is the result of melting and weakening permafrost due to moving water. It can occur both along rivers and at

2160-510: Is host to two major public limestone caves. Penn's Cave , located just east of Centre Hall, is an all water limestone cave and wildlife center unique in the United States. For centuries the few dry rooms above the water were used as shelter by Native Americans and European trappers ; in 1885 the cave was officially opened as a show cavern and the nearby Penn's Cave Hotel was opened the same year. On its 91st anniversary in 1976 both

2250-535: Is located in Centre Hall and takes place during the final week of August. As a tradition since 1874, The Grange Fair draws thousands of people from across the Central PA region. The fair also acts as the last week of summer for many organizations around Centre County. The fairgrounds also become a city within a town , as fairgoers are able to move-in for the duration of the fair. The HOPE Fund of Penns Valley

2340-486: Is located on the western border of Spring Mills and in the center of greater Penns Valley along PA 45. As Egg Hill separates Georges Valley from Penns Valley so too does Brush Mountain from Brush Valley. Brush Mountain raises to an elevation of 1,936 ft and has one large pass, the Millheim Narrows, cut by Elk Creek. This pass allows travel from Rebersburg to Millheim and greater Penns Valley. Penns Valley

2430-578: Is located on the western boundary of Penns Valley and has a surface area of 77 acres. Boating and fishing are permitted and as part of the Cooperative Fish Habitat Improvement Program through the Pennsylvania Fish and Boat Commission , the lake has been host to fish habitat structures to support fish populations. As of March 2013 Colyer Lake has been slated for indefinite draining until deficiencies in

2520-405: Is of two primary varieties: deflation , where the wind picks up and carries away loose particles; and abrasion , where surfaces are worn down as they are struck by airborne particles carried by wind. Deflation is divided into three categories: (1) surface creep , where larger, heavier particles slide or roll along the ground; (2) saltation , where particles are lifted a short height into

2610-404: Is sparse and soil is dry (and so is more erodible). Other climatic factors such as average temperature and temperature range may also affect erosion, via their effects on vegetation and soil properties. In general, given similar vegetation and ecosystems, areas with more precipitation (especially high-intensity rainfall), more wind, or more storms are expected to have more erosion. In some areas of

2700-457: Is the main climatic factor governing soil erosion by water. The relationship is particularly strong if heavy rainfall occurs at times when, or in locations where, the soil's surface is not well protected by vegetation . This might be during periods when agricultural activities leave the soil bare, or in semi-arid regions where vegetation is naturally sparse. Wind erosion requires strong winds, particularly during times of drought when vegetation

2790-400: Is where particles/sea load carried by the waves are worn down as they hit each other and the cliffs. This then makes the material easier to wash away. The material ends up as shingle and sand. Another significant source of erosion, particularly on carbonate coastlines, is boring, scraping and grinding of organisms, a process termed bioerosion . Sediment is transported along the coast in

Penns Valley - Misplaced Pages Continue

2880-627: The Appalachian Mountains , intensive farming practices have caused erosion at up to 100 times the natural rate of erosion in the region. Excessive (or accelerated) erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and (on natural landscapes ) ecological collapse , both because of loss of the nutrient-rich upper soil layers . In some cases, this leads to desertification . Off-site effects include sedimentation of waterways and eutrophication of water bodies , as well as sediment-related damage to roads and houses. Water and wind erosion are

2970-521: The Appalachian orogeny . Nittany Mountain is part of a synclinal depression of the anticlinal Nittany Arch , which originally formed a huge mountain, since eroded, that towered over what is now Nittany Valley. The present Nittany and Big Mountain ridges were originally a valley in this ancient mountain. The Nittany ridge line is topped by the erosion-resistant Bald Eagle Sandstone. The more durable Tuscarora Quartzite formations are found exposed on

3060-664: The Great Plains , it is estimated that soil loss due to wind erosion can be as much as 6100 times greater in drought years than in wet years. Mass wasting or mass movement is the downward and outward movement of rock and sediments on a sloped surface, mainly due to the force of gravity . Mass wasting is an important part of the erosional process and is often the first stage in the breakdown and transport of weathered materials in mountainous areas. It moves material from higher elevations to lower elevations where other eroding agents such as streams and glaciers can then pick up

3150-737: The Timanides of Northern Russia. Erosion of this orogen has produced sediments that are now found in the East European Platform , including the Cambrian Sablya Formation near Lake Ladoga . Studies of these sediments indicate that it is likely that the erosion of the orogen began in the Cambrian and then intensified in the Ordovician . If the erosion rate exceeds soil formation , erosion destroys

3240-1027: The U.S. Census Bureau for the purposes of compiling demographic data. They are not actual jurisdictions under Pennsylvania law. Other unincorporated communities, such as villages, may be listed here as well. As of the 2010 census, the Penns Valley area had 12,819 people living in the area. The most populous municipality is Potter Township with 3,517 people followed by 2,405 people living in Gregg Township, 1,983 people living in Miles Township, 1,564 people living in Haines Township, and 1,181 people living in Penn Township. There were 1,265 people living in Centre Hall borough and 904 people in Millheim borough. The Centre County Grange Encampment and Fair , also known simply as The Grange Fair ,

3330-416: The accumulation zone above the glacial equilibrium line altitude), which causes increased rates of erosion of the mountain, decreasing mass faster than isostatic rebound can add to the mountain. This provides a good example of a negative feedback loop . Ongoing research is showing that while glaciers tend to decrease mountain size, in some areas, glaciers can actually reduce the rate of erosion, acting as

3420-405: The impact of a falling raindrop creates a small crater in the soil , ejecting soil particles. The distance these soil particles travel can be as much as 0.6 m (2.0 ft) vertically and 1.5 m (4.9 ft) horizontally on level ground. If the soil is saturated , or if the rainfall rate is greater than the rate at which water can infiltrate into the soil, surface runoff occurs. If

3510-455: The lower crust and mantle . Because tectonic processes are driven by gradients in the stress field developed in the crust, this unloading can in turn cause tectonic or isostatic uplift in the region. In some cases, it has been hypothesised that these twin feedbacks can act to localize and enhance zones of very rapid exhumation of deep crustal rocks beneath places on the Earth's surface with extremely high erosion rates, for example, beneath

3600-407: The surface runoff which may result from rainfall, produces four main types of soil erosion : splash erosion , sheet erosion , rill erosion , and gully erosion . Splash erosion is generally seen as the first and least severe stage in the soil erosion process, which is followed by sheet erosion, then rill erosion and finally gully erosion (the most severe of the four). In splash erosion ,

3690-525: The 200-foot-long Hall of Statues. This solution limestone cave can be toured in 50 minutes and has both cabin rentals and campground facilities. Under Pennsylvania law, there are five types of incorporated municipalities: cities, home rule municipalities, boroughs, townships, and towns. The following municipalities, boroughs and townships are located in Penns Valley: Census-designated places are geographical areas designated by

Penns Valley - Misplaced Pages Continue

3780-499: The 21st century, a strong link has been drawn between the increase in storm frequency with an increase in sediment load in rivers and reservoirs, highlighting the impacts climate change can have on erosion. Vegetation acts as an interface between the atmosphere and the soil. It increases the permeability of the soil to rainwater, thus decreasing runoff. It shelters the soil from winds, which results in decreased wind erosion, as well as advantageous changes in microclimate. The roots of

3870-717: The Center County Library system. Penns Valley is home to two state parks and large tracts of state forest . The state parks, Poe Valley State Park and Poe Paddy State Park are located just minutes from each other. Both parks have extensive hiking trails which link up to the trails of the surrounding and extensive lands of the Bald Eagle State Forest . Poe Valley State Park is host to Poe Lake which has overnight camping facilities for summer visitors and guided walks, evening amphitheater programs and other special activities are available during

3960-648: The Central Pennsylvania Institute of Science and Technology in Pleasant Gap, Pennsylvania . The Penns Valley Region is host to 12 private schools, the most in the county. Many of these schools are operated for the use of the large Amish community within Penns Valley. The Centre County Libraries has a branch in Centre Hall and operates a bookmobile that provides service to the Penns Valley area. The East Penns Valley Library has been an all volunteer library since 2013 after their split from

4050-433: The air, and bounce and saltate across the surface of the soil; and (3) suspension , where very small and light particles are lifted into the air by the wind, and are often carried for long distances. Saltation is responsible for the majority (50–70%) of wind erosion, followed by suspension (30–40%), and then surface creep (5–25%). Wind erosion is much more severe in arid areas and during times of drought. For example, in

4140-413: The amount of eroded material that is already carried by, for example, a river or glacier. The transport of eroded materials from their original location is followed by deposition, which is arrival and emplacement of material at a new location. While erosion is a natural process, human activities have increased by 10–40 times the rate at which soil erosion is occurring globally. At agriculture sites in

4230-601: The area is Penns Creek whose headwaters are located south of Centre Hall in Penns Cave. It travels downstream linking with Sinking Creek in Spring Mills and flows to the town of Coburn. There it joins Elk Creek whose headwaters are in eastern Brush valley. From Coburn, it flows through the Seven Mountains and into Union County. There are also two lakes within Penns Valley, each which are controlled by dams: Poe Lake and Colyer Lake. Being fed by Sinking Creek, Colyer Lake

4320-470: The base along with the glacier. This method produced some of the many thousands of lake basins that dot the edge of the Canadian Shield . Differences in the height of mountain ranges are not only being the result tectonic forces, such as rock uplift, but also local climate variations. Scientists use global analysis of topography to show that glacial erosion controls the maximum height of mountains, as

4410-562: The cave and hotel were placed on the National Register of Historic Places . The cave is accessed by guided boat tours through the cavern. The second public cave in Penns Valley is Woodward Cave. Located in the village of Woodward, Woodward cave is one of the largest in the state featuring the 14-foot Tower of Babel stalagmite , 60-foot cathedral ceiling in the Upper Room, the ballroom which is large enough to host banquets, and

4500-522: The coast. Rapid river channel migration observed in the Lena River of Siberia is due to thermal erosion, as these portions of the banks are composed of permafrost-cemented non-cohesive materials. Much of this erosion occurs as the weakened banks fail in large slumps. Thermal erosion also affects the Arctic coast , where wave action and near-shore temperatures combine to undercut permafrost bluffs along

4590-409: The coastline. Where there is a bend in the coastline, quite often a buildup of eroded material occurs forming a long narrow bank (a spit ). Armoured beaches and submerged offshore sandbanks may also protect parts of a coastline from erosion. Over the years, as the shoals gradually shift, the erosion may be redirected to attack different parts of the shore. Erosion of a coastal surface, followed by

SECTION 50

#1732787080739

4680-407: The collision of the modern-day eastern seaboard of the then Euramerican continent with Africa , then Gondwana , about 290 million years ago forming the supercontinent Pangea . Since the collision event the mountains have been eroding from the breakup of Pangea and through sedimentation formed the coastal plains to the east and limestone plateaus to the west. The footprints of the mountains formed

4770-422: The dam being completed in 1937. Nittany Mountain is part of a synclinal depression of the anticlinal Nittany Arch, which originally formed a huge mountain, that has since eroded, during the Appalachian orogeny . Topped by erosion resistant sandstone the mountain forms a barrier between Penns Valley, and Brush Valley, to the south and Nittany Valley to the north. The southern mountainous border of Penns Valley

4860-595: The dam can be resolved. Poe Lake is a 25-acre lake at the southern boundary of Penns Valley. The lake is located in Poe Valley State Park which, in turn, is surrounded by 198,000 acre Bald Eagle State Forest. The lake itself was named for the Big Poe Creek which feeds the reservoir. Access to the reservoir and the reservoir's dam were both constructed by the CCC in the mid to late 1930s, specifically with

4950-411: The direction of the prevailing current ( longshore drift ). When the upcurrent supply of sediment is less than the amount being carried away, erosion occurs. When the upcurrent amount of sediment is greater, sand or gravel banks will tend to form as a result of deposition . These banks may slowly migrate along the coast in the direction of the longshore drift, alternately protecting and exposing parts of

5040-405: The extremely steep terrain of Nanga Parbat in the western Himalayas . Such a place has been called a " tectonic aneurysm ". Human land development, in forms including agricultural and urban development, is considered a significant factor in erosion and sediment transport , which aggravate food insecurity . In Taiwan, increases in sediment load in the northern, central, and southern regions of

5130-582: The flood regions result from glacial Lake Missoula , which created the channeled scablands in the Columbia Basin region of eastern Washington . Wind erosion is a major geomorphological force, especially in arid and semi-arid regions. It is also a major source of land degradation, evaporation, desertification, harmful airborne dust, and crop damage—especially after being increased far above natural rates by human activities such as deforestation , urbanization , and agriculture . Wind erosion

5220-539: The following two hundred years the iron industry would wane, but the agricultural heritage within Penns Valley would continue, and with the growth of a small land grant university just to the west in State College , The Pennsylvania State University would give the region a new academic wave of prosperity for the 21st century. The Penns Valley region is part of the Chesapeake watershed . The main waterway in

5310-417: The growth of protective vegetation ( rhexistasy ) are a key element of badland formation. Valley or stream erosion occurs with continued water flow along a linear feature. The erosion is both downward , deepening the valley , and headward , extending the valley into the hillside, creating head cuts and steep banks. In the earliest stage of stream erosion, the erosive activity is dominantly vertical,

5400-465: The higher ridges of the northern end of the same syncline: Big Mountain to "Riansares Mountain" and Big Kettle Mountain to "The Winehead". The more easily eroded Juniata Shale forms the depression between the lower and higher ridges, and the drainage from this area cut small ravines in the Nittany ridge line. The same three rock layers are exposed in the neighboring ridges. Beneath the sedimentary layers

5490-411: The island can be tracked with the timeline of development for each region throughout the 20th century. The intentional removal of soil and rock by humans is a form of erosion that has been named lisasion . Mountain ranges take millions of years to erode to the degree they effectively cease to exist. Scholars Pitman and Golovchenko estimate that it takes probably more than 450 million years to erode

SECTION 60

#1732787080739

5580-540: The larger Nittany Valley to the west. There are two smaller subordinate valleys typically associated with the greater valley: Georges Valley in the south, separated by Egg Hill, and Brush Valley in the north, separated by Brush Mountain. The Appalachian Mountain chain was formed starting around 420 million years ago with the collision of the North American craton and the Iapetus Ocean and culminating with

5670-409: The local slope (see above), this will change the rates of erosion in the uplifted area. Active tectonics also brings fresh, unweathered rock towards the surface, where it is exposed to the action of erosion. However, erosion can also affect tectonic processes. The removal by erosion of large amounts of rock from a particular region, and its deposition elsewhere, can result in a lightening of the load on

5760-418: The material and move it to even lower elevations. Mass-wasting processes are always occurring continuously on all slopes; some mass-wasting processes act very slowly; others occur very suddenly, often with disastrous results. Any perceptible down-slope movement of rock or sediment is often referred to in general terms as a landslide . However, landslides can be classified in a much more detailed way that reflects

5850-407: The material has begun to slide downhill. In some cases, the slump is caused by water beneath the slope weakening it. In many cases it is simply the result of poor engineering along highways where it is a regular occurrence. Surface creep is the slow movement of soil and rock debris by gravity which is usually not perceptible except through extended observation. However, the term can also describe

5940-438: The mechanisms responsible for the movement and the velocity at which the movement occurs. One of the visible topographical manifestations of a very slow form of such activity is a scree slope. Slumping happens on steep hillsides, occurring along distinct fracture zones, often within materials like clay that, once released, may move quite rapidly downhill. They will often show a spoon-shaped isostatic depression , in which

6030-481: The money needed to buy the mountain. In 1981, Lion's Paw established the Mount Nittany Conservancy, an organization intended to raise money from the general public in addition to the money raised by Lion's Paw members. Since its establishment, the Mount Nittany Conservancy has purchased hundreds of additional acres on Mount Nittany. In 2013, Conserving Mount Nittany: A Dynamic Environmentalism ,

6120-484: The morphologic impact of glaciations on active orogens, by both influencing their height, and by altering the patterns of erosion during subsequent glacial periods via a link between rock uplift and valley cross-sectional shape. At extremely high flows, kolks , or vortices are formed by large volumes of rapidly rushing water. Kolks cause extreme local erosion, plucking bedrock and creating pothole-type geographical features called rock-cut basins . Examples can be seen in

6210-404: The most erosion occurs during times of flood when more and faster-moving water is available to carry a larger sediment load. In such processes, it is not the water alone that erodes: suspended abrasive particles, pebbles , and boulders can also act erosively as they traverse a surface, in a process known as traction . Bank erosion is the wearing away of the banks of a stream or river. This

6300-604: The most significant environmental problems . Often in the United States, farmers cultivating highly erodible land must comply with a conservation plan to be eligible for agricultural assistance. Nittany Mountain Penn State University lies at the foot of Mount Nittany; the athletic teams and the mascot of the school, the Nittany Lion , are named for the mountain, as are Mount Nittany Elementary and Mount Nittany Middle School. The word "Nittany"

6390-434: The nutrient-rich upper soil layers . In some cases, the eventual result is desertification . Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses. Water and wind erosion are the two primary causes of land degradation ; combined, they are responsible for about 84% of the global extent of degraded land , making excessive erosion one of

6480-423: The oldest town of Centre County, Aaronsburg , which was planned out in 1786. At the close of the 18th century Penns Valley was already set aside for farmland, however, the surrounding county rapidly boomed as iron ore was discovered and the first road built by Philadelphia land speculator Reuben Haines brought the rest of Pennsylvania into the heart of Penns Valley terminating at the location of Spring Mills. In

6570-411: The order of a few centimetres (about an inch) or less and along-channel slopes may be quite steep. This means that rills exhibit hydraulic physics very different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when runoff water accumulates and rapidly flows in narrow channels during or immediately after heavy rains or melting snow, removing soil to

6660-556: The plants bind the soil together, and interweave with other roots, forming a more solid mass that is less susceptible to both water and wind erosion. The removal of vegetation increases the rate of surface erosion. The topography of the land determines the velocity at which surface runoff will flow, which in turn determines the erosivity of the runoff. Longer, steeper slopes (especially those without adequate vegetative cover) are more susceptible to very high rates of erosion during heavy rains than shorter, less steep slopes. Steeper terrain

6750-413: The relief between mountain peaks and the snow line are generally confined to altitudes less than 1500 m. The erosion caused by glaciers worldwide erodes mountains so effectively that the term glacial buzzsaw has become widely used, which describes the limiting effect of glaciers on the height of mountain ranges. As mountains grow higher, they generally allow for more glacial activity (especially in

6840-454: The ridge and valley geological region in which Penns Valley was formed through glacial and other activity. More recently the area now known as Penns Valley was discovered by General James Potter in 1764 who trekked through the region and observed the prairies and woodlands of the area and settled at Old Fort, near Centre Hall , in 1774. Upon observing the valley from above he exclaimed, "... I have discovered an empire." Penns Valley also hosts

6930-828: The rolling of dislodged soil particles 0.5 to 1.0 mm (0.02 to 0.04 in) in diameter by wind along the soil surface. On the continental slope , erosion of the ocean floor to create channels and submarine canyons can result from the rapid downslope flow of sediment gravity flows , bodies of sediment-laden water that move rapidly downslope as turbidity currents . Where erosion by turbidity currents creates oversteepened slopes it can also trigger underwater landslides and debris flows . Turbidity currents can erode channels and canyons into substrates ranging from recently deposited unconsolidated sediments to hard crystalline bedrock. Almost all continental slopes and deep ocean basins display such channels and canyons resulting from sediment gravity flows and submarine canyons act as conduits for

7020-515: The runoff has sufficient flow energy , it will transport loosened soil particles ( sediment ) down the slope. Sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes. Generally, where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are typically of

7110-666: The sea and waves ; glacial plucking , abrasion , and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows . The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion proceeds the fastest on steeply sloping surfaces, and rates may also be sensitive to some climatically controlled properties including amounts of water supplied (e.g., by rain), storminess, wind speed, wave fetch , or atmospheric temperature (especially for some ice-related processes). Feedbacks are also possible between rates of erosion and

7200-538: The shoreline and cause them to fail. Annual erosion rates along a 100-kilometre (62-mile) segment of the Beaufort Sea shoreline averaged 5.6 metres (18 feet) per year from 1955 to 2002. Most river erosion happens nearer to the mouth of a river. On a river bend, the longest least sharp side has slower moving water. Here deposits build up. On the narrowest sharpest side of the bend, there is faster moving water so this side tends to erode away mostly. Rapid erosion by

7290-593: The soil. Lower rates of erosion can prevent the formation of soil features that take time to develop. Inceptisols develop on eroded landscapes that, if stable, would have supported the formation of more developed Alfisols . While erosion of soils is a natural process, human activities have increased by 10-40 times the rate at which erosion occurs globally. Excessive (or accelerated) erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and (on natural landscapes ) ecological collapse , both because of loss of

7380-403: The summer months. In the winter roads may by inaccessible but use of registered snowmobiles is allowed. Poe Paddy State Park is just east and provides access to fishing through Penns Creek. There are also limited camping facilities but they can be supplemented through the use of Poe Valley's amenities. Penns Valley has three main state routes that connect the valley both within itself and to

7470-542: The surrounding region. PA 144 is a north–south route that begins as a branch from US 322 in Potters Mills running through Centre Hall and crossing Nittany Mountain into Pleasant Gap and the Bellefonte area. PA 192 runs east–west through upper Penns Valley in the subordinate Brush Valley. This route acts as one of two connections from Union County into Centre County and State College. The second of these two routes

7560-433: The terminus or during glacier retreat . The best-developed glacial valley morphology appears to be restricted to landscapes with low rock uplift rates (less than or equal to 2mm per year) and high relief, leading to long-turnover times. Where rock uplift rates exceed 2mm per year, glacial valley morphology has generally been significantly modified in postglacial time. Interplay of glacial erosion and tectonic forcing governs

7650-409: The transfer of sediment from the continents and shallow marine environments to the deep sea. Turbidites , which are the sedimentary deposits resulting from turbidity currents, comprise some of the thickest and largest sedimentary sequences on Earth, indicating that the associated erosional processes must also have played a prominent role in Earth's history. The amount and intensity of precipitation

7740-563: The two primary causes of land degradation ; combined, they are responsible for about 84% of the global extent of degraded land, making excessive erosion one of the most significant environmental problems worldwide. Intensive agriculture , deforestation , roads , anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall , and

7830-427: The valleys have a typical V-shaped cross-section and the stream gradient is relatively steep. When some base level is reached, the erosive activity switches to lateral erosion, which widens the valley floor and creates a narrow floodplain. The stream gradient becomes nearly flat, and lateral deposition of sediments becomes important as the stream meanders across the valley floor. In all stages of stream erosion, by far

7920-554: The world (e.g. western Europe ), runoff and erosion result from relatively low intensities of stratiform rainfall falling onto the previously saturated soil. In such situations, rainfall amount rather than intensity is the main factor determining the severity of soil erosion by water. According to the climate change projections, erosivity will increase significantly in Europe and soil erosion may increase by 13–22.5% by 2050 In Taiwan , where typhoon frequency increased significantly in

8010-491: The world (e.g. the mid-western US ), rainfall intensity is the primary determinant of erosivity (for a definition of erosivity check, ) with higher intensity rainfall generally resulting in more soil erosion by water. The size and velocity of rain drops is also an important factor. Larger and higher-velocity rain drops have greater kinetic energy , and thus their impact will displace soil particles by larger distances than smaller, slower-moving rain drops. In other regions of

8100-469: Was already in use by the time Pennsylvania State University was founded. Some sources cite the word Nit-A-Nee as meaning "barrier against the wind". In 1945, the landowners of Mount Nittany were preparing to sell the mountain, allegedly to use timber rights . The alumni of the Lion's Paw Senior Society who heard of this bought an option to buy the mountain. It took the Lion's Paw alumni until May 1946 to raise

#738261