Sag (geology)

In geology a sag, or trough, is a depressed, persistent, low area; the opposite of an arch, or ridge, a raised, persistent, high area. The terms sag and arch were used historically to describe very large features, for example, characterizing North America as two arches with a sag between them.

Also, a sag is a former river bed which has been partially filled with debris from glaciation or other natural processes but which is still visible in the surface terrain. Sags formed by the former river beds of large rivers often become the valleys of smaller streams after a change of course by the main river.

Examples of sags include the former continuations of the Grand, Moreau and White rivers in South Dakota in the United States. Before the last ice age these rivers continued eastward past their current confluences with the present course of Missouri River. The sags are prominently visible on the plateau of the Coteau du Missouri, allowing small streams to drain into the Missouri from its eastern side.

Geology

Geology (from the Greek γῆ, gē, i.e. "earth" and -λoγία, -logia, i.e. "study of, discourse") is an earth science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which they change. Geology can also refer generally to the study of the solid features of any celestial body (such as the geology of the Moon or Mars).

Geology gives insight into the history of the Earth by providing the primary evidence for plate tectonics, the evolutionary history of life, and past climates. Geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, and for providing insights into past climate change. Geology also plays a role in geotechnical engineering and is a major academic discipline.

Geologic materials

The majority of geological data comes from research on solid Earth materials. These typically fall into one of two categories: rock and unconsolidated material.

Country rock (geology)

Country rock is a geological term meaning the rock native to an area. It is similar and in many cases interchangeable with the terms basement and wall rocks.

The term is used to denote the usual strata of a region in relation to the rock which is being discussed or observed.

The following are areas in geology when the term country rock is used;

Geology (journal)

Geology is a publication of the Geological Society of America (GSA). The GSA claims that it is the most widely read scientific journal in the field of earth science. It is published monthly, with each issue containing 20 or more articles, and an annual total of 1166 pages.

One of the goals of the journal is to provide a forum for shorter articles and less focus on pure academic research type articles.

See also

References

External links

SAG

SAG is the acronym for:

SAg is the abbreviation for:

Sag (or Sâg, Șag, Šag) may refer to:

Voltage sag

A voltage sag (U.S. English) or voltage dip (British English) is a short duration reduction in rms voltage which can be caused by a short circuit, overload or starting of electric motors. A voltage sag happens when the rms voltage decreases between 10 and 90 percent of nominal voltage for one-half cycle to one minute. Some references defines the duration of a sag for a period of 0.5 cycle to a few seconds, and longer duration of low voltage would be called a "sustained sag".

Related notions

The term "sag" should not be confused with brownout which is the reduction of voltage for minutes or hours.

The term "transient" as used in power quality is an umbrella term and can refer to sags, but also to swells, dropouts etc.

Swell

Voltage swell is the opposite of voltage sag. Voltage swell, which is a momentary increase in voltage, happens when a heavy load turns off in a power system.

Causes

There are several factors which cause a voltage sag to happen:

2010 South Asian Games

The 2010 South Asian Games, officially the XI South Asian Games, was a major multi-sport event that took place from 29 January to 8 February 2010 in Dhaka, Bangladesh. This was the third time that the Bangladeshi capital hosted the Games, thus becoming the first city to hold the games three times.

Roughly 2000 athletes from eight countries competed at the games in 23 different sports. The sporting giant of the region, India continued its dominance in the game's medal tally with a staggering 175 medals including 90 gold medals. Pakistan narrowly beat the host country in gold medals count with 19, while the host Bangladesh captured 18 golds including the region's most popular and prestigious football and cricket titles. Bangladesh, however, earned second spot in total medal count beating out Pakistan. Sri Lanka’s Shehan Abeypitiya becomes the fastest man while Pakistan’s Naseem Hamid was crowned the fastest woman of the region winning 100 meter sprint.

Organization

The 11th South Asian Games were originally scheduled to take place in November 2009. However, the host country (Bangladesh) faced difficulties due to general elections. As a result, the South Asian Association Council (SAOC) held the 39th Executive Meeting and decided against hosting the Games in 2009, postponing the games to early 2010.