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Misfit Stream
A misfit stream is a river that is either too large or too small to have eroded the valley or cave passage in which it flows. This term is also used for a stream or river with meanders that obviously are not proportional in size to the meanders of the valley or meander scars cut into its valley walls. If the misfit stream is too large for either its valley or meanders, it is known as an overfit stream. If the misfit stream is too small for either its valley or meanders, it is known as an underfit stream.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, J.A., eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. Dury, G. H. (1964) ''Subsurface Exploration and Chronology of Underfit Streams.'' Professional Paper no. 452-A. U.S. Geological Survey, Reston, Virginia. The term ''misfit stream'' is often used as a synonym for an underfit stream. Origin An underfit stream can result when glaciation modifies the landscape by creati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glaciation
A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate between glacial periods. The Last Glacial Period ended about 15,000 years ago. The Holocene is the current interglacial. A time with no glaciers on Earth is considered a greenhouse climate state. Quaternary Period Within the Quaternary, which started about 2.6 million years before present, there have been a number of glacials and interglacials. At least eight glacial cycles have occurred in the last 740,000 years alone. Changes in atmospheric and associated radiative forcing were among the primary drivers of globally cold glacial and warm interglacial climates, with changes in ocean physical circulation, biological productivity and seawater acid-base chemistry likely causing most of the recorded changes Penultimate Glacial Period The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
U-shaped Valley
U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of Glacial period, glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom (by contrast, valleys carved by rivers tend to be V-shaped in cross-section). Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring. When the ice recedes or thaws, the valley remains, often littered with small boulders that were transported within the ice, called Till, glacial till or glacial erratic. Examples of U-shaped valleys are found in mountainous regions throughout the world including the Andes, Alps, Caucasus Mountains, Himalaya, Rocky Mountains, New Zealand and the Scandinavian Mountains. They are found also in other major European mountains including the Carpathian Mountains, the Pyrenees, the Rila and Pirin moun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valley
A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over a very long period. Some valleys are formed through erosion by glacial ice. These glaciers may remain present in valleys in high mountains or polar areas. At lower latitudes and altitudes, these glacially formed valleys may have been created or enlarged during ice ages but now are ice-free and occupied by streams or rivers. In desert areas, valleys may be entirely dry or carry a watercourse only rarely. In areas of limestone bedrock, dry valleys may also result from drainage now taking place underground rather than at the surface. Rift valleys arise principally from earth movements, rather than erosion. Many different types of valleys are described by geographers, using terms that may be global in use or else applied only locally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discharge (hydrology)
In hydrology, discharge is the volumetric flow rate (volume per time, in units of m3/h or ft3/h) of a stream. It equals the product of average flow velocity (with dimension of length per time, in m/h or ft/h) and the cross-sectional area (in m2 or ft2). It includes any suspended solids (e.g. sediment), dissolved chemicals like (aq), or biologic material (e.g. diatoms) in addition to the water itself. Terms may vary between disciplines. For example, a fluvial hydrologist studying natural river systems may define discharge as streamflow, whereas an engineer operating a reservoir system may equate it with outflow, contrasted with inflow. Formulation A discharge is a measure of the quantity of any fluid flow over unit time. The quantity may be either volume or mass. Thus the water discharge of a tap (faucet) can be measured with a measuring jug and a stopwatch. Here the discharge might be 1 litre per 15 seconds, equivalent to 67 ml/second or 4 litres/minute. This is an average meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climate Change (general Concept)
Present-day climate change includes both global warming—the ongoing increase in global average temperature—and its wider effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to Earth's climate. The current rise in global temperatures is driven by human activities, especially fossil fuel burning since the Industrial Revolution. Fossil fuel use, deforestation, and some agricultural and industrial practices release greenhouse gases. These gases absorb some of the heat that the Earth radiates after it warms from sunlight, warming the lower atmosphere. Carbon dioxide, the primary gas driving global warming, has increased in concentration by about 50% since the pre-industrial era to levels not seen for millions of years. Climate change has an increasingly large impact on the environment. Deserts are expanding, while heat waves and wildfires are becoming more common. Amplified warming in the Arctic has cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precipitation (meteorology)
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwealth usage), snow, ice pellets, graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor (reaching 100% relative humidity), so that the water condenses and "precipitates" or falls. Thus, fog and mist are not precipitation; their water vapor does not condense sufficiently to precipitate, so fog and mist do not fall. (Such a non-precipitating combination is a colloid.) Two processes, possibly acting together, can lead to air becoming saturated with water vapor: cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called shower (p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groundwater
Groundwater is the water present beneath Earth's surface in rock and Pore space in soil, soil pore spaces and in the fractures of stratum, rock formations. About 30 percent of all readily available fresh water in the world is groundwater. A unit of rock or an unconsolidated deposit is called an ''aquifer'' when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the ''water table''. Groundwater is Groundwater recharge, recharged from the surface; it may discharge from the surface naturally at spring (hydrosphere), springs and Seep (hydrology), seeps, and can form oasis, oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction water well, wells. The study of the distribution and movement of groundwater is ''hydrogeology'', also called groundwater hydrology. Typically, groundwater is thought o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stream Capture
Stream capture, river capture, river piracy or stream piracy is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed, and flows down to the bed of a neighbouring stream. This can happen for several reasons, including: *Tectonic earth movements, where the slope of the land changes, and the stream is tipped out of its former course *Natural damming, such as by a landslide or ice sheet *Erosion, either ** Headward erosion of one stream valley upwards into another, or **Lateral erosion of a meander through the higher ground dividing the adjacent streams. **Within an area of karst topography, where streams may ''sink'', or flow underground (a sinking or losing stream) and then reappear in a nearby stream valley *Glacier retreat The cause is not always clear. The additional water flowing down the capturing stream may accelerate erosion and encourage the development of a canyon (gorge). The now-dry valley of the o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waikato River
The Waikato River is the longest river in New Zealand, running for through the North Island. It rises on the eastern slopes of Mount Ruapehu, joining the Tongariro River system and flowing through Lake Taupō, New Zealand's largest lake. It then drains Taupō at the lake's northeastern edge, creates the Huka Falls, and flows northwest through the Waikato Plains. It empties into the Tasman Sea south of Auckland, at Port Waikato. It gives its name to the Waikato region that surrounds the Waikato Plains. The present course of the river was largely formed about 17,000 years ago. Contributing factors were climate warming, forest being reestablished in the river headwaters and the deepening, rather than widening, of the existing river channel. The channel was gradually eroded as far up river as Piarere, leaving the old Hinuera channel through the Hinuera Gap high and dry. The remains of the old course are seen clearly at Hinuera, where the cliffs mark the ancient river edges. The Wai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hauraki Plains
The Hauraki Plains are a geographical area located in the northern North Island of New Zealand, at the lower (northern) end of the Thames Valley, New Zealand, Thames Valley. They are located 75 kilometres south-east of Auckland, at the foot of the Coromandel Peninsula and occupy the southern portion of a rift valley bounded on the north-west by the Hunua Ranges, to the east by the Coromandel Range, Coromandel and Kaimai Range, Kaimai ranges and to the west by a series of undulating hills which separate the plains from the much larger plains of the Waikato River. The Plains are not presently a single administrative area, though a Hauraki Plains County Council existed from 1920 to 1989 and a statistical Meshblock#New Zealand, Area Unit remains. Broadly, the northern and southern parts of the Hauraki Plains are administered by the Hauraki District and the Matamata-Piako District respectively. The alluvial plains have been built up by sediment deposited by the Piako River, Piako a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Island
The North Island ( , 'the fish of Māui', historically New Ulster) is one of the two main islands of New Zealand, islands of New Zealand, separated from the larger but less populous South Island by Cook Strait. With an area of , it is the List of islands by area, world's 14th-largest island, constituting 43% of New Zealand's land area. It has a population of which is % of New Zealand's residents, making it the most populous island in Polynesia and the List of islands by population, 28th-most-populous island in the world. Twelve main urban areas (half of them officially cities) are in the North Island. From north to south, they are Whangārei, Auckland, Hamilton, New Zealand, Hamilton, Tauranga, Rotorua, Gisborne, New Zealand, Gisborne, New Plymouth, Napier, New Zealand, Napier, Hastings, New Zealand, Hastings, Whanganui, Palmerston North, and New Zealand's capital city Wellington, which is located at the south-west tip of the island. Naming and usage The island has been known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
