Hills
A hill is a landform that extends above the surrounding
terrain. Hills often have a distinct summit, a point on a surface that is higher in elevation than all points immediately adjacent to it.
A hill is generally somewhat lower and less steep than a mountain. Artificial, man made, hills may be referred to by a variety of technical names, including mound and tumulus.
There are various specific names used to describe particular types of hill,
based on appearance and method of formation. Many such names originated in one
geographical region to describe a type of hill formation peculiar to that
region, though the names are often adopted by geologists and used in a wider geographical
context. These include:
Drumlin – an elongated whale-shaped hill formed by glacial action.
Butte – an isolated hill with steep sides and a small flat top, formed by weathering.
Tor – a rock formation found on a hilltop; also used to refer to the hill itself, especially in South West England.
Puy – used especially in the Auvergne, France, to describe a conical volcanic hill.
Pingo – a mound of earth-covered ice found in the Arctic and Antarctica.
Hills may form through a number of geomorphic phenomena:
- faulting,
- erosion of larger landforms, such as mountains
- movement and deposition of sediment by glaciers
The rounded peaks of hills results from the movement of soil and loose growth covering the hill, a process known as downhill creep.
Areas that would otherwise have hills do not because of glacier cover during the Ice Age. The hills that existed before the ice age were worn down by the ice (and the rocks they carry) and/or the surrounding valleys and hollows were filled in with glacial drift, therefore leaving a level topography.
Many settlements were originally built on hills, either to avoid or curb floods, particularly if they were near a large body of water, or for defence, since they offer a good view of the surrounding land and require would-be attackers to fight uphill. For example, Ancient Rome was built on seven hills, protecting it from invaders.
Hills provide a major advantage to an army, giving them an elevated firing position and forcing an opposing army to charge uphill to attack them. They may also conceal forces behind them, allowing a force to lay in wait on the crest of a hill, using that crest for cover, and firing on unsuspecting attackers as they broach the hilltop.
Examples of man made hills
- Blackstrap Ski Hill (148 ft)
- Silbury Hill (130 ft)
- Grizzly Peak, Disneland Resort (112 ft)
- Mount Manisty (100 ft)
- Monks Mound (98 ft)
- Mount Gushmore (89 ft)
terrain. Hills often have a distinct summit, a point on a surface that is higher in elevation than all points immediately adjacent to it.
A hill is generally somewhat lower and less steep than a mountain. Artificial, man made, hills may be referred to by a variety of technical names, including mound and tumulus.
There are various specific names used to describe particular types of hill,
based on appearance and method of formation. Many such names originated in one
geographical region to describe a type of hill formation peculiar to that
region, though the names are often adopted by geologists and used in a wider geographical
context. These include:
Drumlin – an elongated whale-shaped hill formed by glacial action.
Butte – an isolated hill with steep sides and a small flat top, formed by weathering.
Tor – a rock formation found on a hilltop; also used to refer to the hill itself, especially in South West England.
Puy – used especially in the Auvergne, France, to describe a conical volcanic hill.
Pingo – a mound of earth-covered ice found in the Arctic and Antarctica.
Hills may form through a number of geomorphic phenomena:
- faulting,
- erosion of larger landforms, such as mountains
- movement and deposition of sediment by glaciers
The rounded peaks of hills results from the movement of soil and loose growth covering the hill, a process known as downhill creep.
Areas that would otherwise have hills do not because of glacier cover during the Ice Age. The hills that existed before the ice age were worn down by the ice (and the rocks they carry) and/or the surrounding valleys and hollows were filled in with glacial drift, therefore leaving a level topography.
Many settlements were originally built on hills, either to avoid or curb floods, particularly if they were near a large body of water, or for defence, since they offer a good view of the surrounding land and require would-be attackers to fight uphill. For example, Ancient Rome was built on seven hills, protecting it from invaders.
Hills provide a major advantage to an army, giving them an elevated firing position and forcing an opposing army to charge uphill to attack them. They may also conceal forces behind them, allowing a force to lay in wait on the crest of a hill, using that crest for cover, and firing on unsuspecting attackers as they broach the hilltop.
Examples of man made hills
- Blackstrap Ski Hill (148 ft)
- Silbury Hill (130 ft)
- Grizzly Peak, Disneland Resort (112 ft)
- Mount Manisty (100 ft)
- Monks Mound (98 ft)
- Mount Gushmore (89 ft)