What is an erg and where can they be found?

What is an erg and where can they be found?

Erg, also called Sand Sea, in a desert region, area of large accumulation of sand, generally in the bottom of a huge basin in which a former river piled up alluvium. Ergs are areas of actively shifting dunes, “fossilized” dunes, or extensive sand sheets.

What is a erg in Algeria?

The Issaouane Erg (sand sea) is located in eastern Algeria between the Tinrhert Plateau to the north and the Fadnoun Plateau to the south. Ergs are vast areas of moving sand with little to no vegetation cover. Considered to be part of the Sahara Desert, the Issaouane Erg covers an area of approximately 38,000 km2.

Where are ergs in Africa?

There are major ergs in northern Africa, southern Africa, the Arabian Peninsula, Central Asia, PAKISTAN, and China. The largest contiguous erg covers 1 million square mi (2.5 million square km) in southern Africa’s KALAHARI DESERT. Natural vegetation has stabilized most of this sand sea.

How are erg formed?

Ergs are formed when sand from abundant sources move downwind and build up into humongous dunes and its movement is slowed down or halted by geological barriers to the flow of wind or by concurring wind flow.

What can an erg diagnose?

Your doctor may perform an ERG to determine if you have an inherited or acquired disorder of the retina, such as:

• retinitis pigmentosa, which is a genetic disease causing loss of peripheral and night vision.
• macular degeneration, which is a loss of vision due to the death of cells in the macula.

What is the point of an erg?

An Employee Resource Group (ERG) is a network within a company where employees meet up (in person or remotely) based on shared characteristics, experiences or goals. The groups offer a chance to network and socialize, work on professional development, and to raise awareness of relevant issues.

What is the difference between ERG and Hamada?

Hamada is related to desert pavement (known variously as reg, serir, gibber or saï), which occurs as stony plains or depressions covered with gravels or boulders, rather than as highland plateaus. Hamadas exist in contrast to ergs, which are large areas of shifting sand dunes.

What is an erg at work?

What are hamadas in Africa?

Hamadas are elevated plateaus of rock and stone that reach heights of 3,353 meters (11,000 feet). They include the Atlas Mountains, which stretch from southwestern Morocco to northeastern Tunisia; the Tibesti Mountains of southern Libya and northern Chad; and the Ahaggar Mountains in southern Algeria.

What is the purpose of an erg?

What does a normal ERG look like?

A normal ERG shows an a-wave (photoreceptor activity) and b-wave (Muller and bipolar cells activity) patterns in dark-adapted (scotopic) and light-adapted (photopic) settings. Wave patterns that are diminished in size or delayed or prolonged in time provide clues about the types of damaged cells.