SATELLITE Pictures

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A powerful earthquake struck southeastern Iran on December 26, 2003, killing thousands and destroying much of the city of Bam. The USGS National Earthquake information center is reporting a magnitude of 6.5 for the quake, which was located just southwest of the city. About 60 percent of the buildings in Bam were destroyed. The old quarter and a 2,000-year-old citadel (severely damaged by the earthquake) were built primarily of mud brick.

Iran is a mountainous country subject to frequent severe earthquakes. A subduction zone where the Arabian Plate is sliding underneath the Eurasian Plate lies inland from, and parallel to, the Persian Gulf coast. This collision is squeezing the edge of the Eurasian plate, resulting in common earthquakes and a series of mountain ranges. Bam is northeast of one of these mountain ranges, the Jebal Barez. Frequent earthquakes occur along the Nayband and Gowk faults, near Bam, but the immediate area experiences relatively few earthquakes.

This image was created from Landsat 7 Enhanced Thematic Mapper Plus (ETM+) data acquired on October 1, 1999.

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The Zagros Mountains in southwestern Iran present an impressive landscape of long linear ridges and valleys. Formed by collision of the Eurasian and Arabian tectonic plates, the ridges and valleys extend hundreds of kilometers. Stresses induced in the Earth’s crust by the collision caused extensive folding of the preexisting layered sedimentary rocks. Subsequent erosion removed softer rocks, such as mudstone (rock formed by consolidated mud) and siltstone (a slightly coarser-grained mudstone) while leaving harder rocks, such as limestone (calcium-rich rock consisting of the remains of marine organisms) and dolomite (rocks similar to limestone containing calcium and magnesium). This differential erosion formed the linear ridges of the Zagros Mountains. The depositional environment and tectonic history of the rocks were conducive to the formation and trapping of petroleum, and the Zagros region is an important part of Persian Gulf production.

This astronaut photograph of the southwestern edge of the Zagros mountain belt includes another common feature of the region—a salt dome (Kuh-e-Namak or “mountain of salt” in Farsi). Thick layers of minerals such as halite (common table salt) typically accumulate in closed basins during alternating wet and dry climatic conditions. Over geologic time, these layers of salt are buried under younger layers of rock. The pressure from overlying rock layers causes the lower-density salt to flow upwards, bending the overlying rock layers and creating a dome-like structure. Erosion has spectacularly revealed the uplifted tan and brown rock layers surrounding the white Kuh-e-Namak to the northwest and southeast (center of image). Radial drainage patterns indicate another salt dome is located to the southwest (image left center). If the rising plug of salt (called a <span class="jargon">salt diapir</span>) breaches the surface, it can become a flowing salt glacier. Salt domes are an important target for oil exploration, as the impermeable salt frequently traps petroleum beneath other rock layers.

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With a population of just over two million, Mashhad is Iran’s second-largest city. It is located in the Kashaf River valley near the northeast corner of the country, not far away from the borders of Turkmenistan and Afganistan. Besides being the capital and center of commerce for Khorasan province, Mashhad is tourist center as well as a site of pilgrimage for millions to the shrine of martyred Shi’ate Imam Reza.

The crew of STS-107 acquired this snow-enhanced image just after noon (local time) on January 21, 2003. The long runways of the international airport, on the southeastern edge of the city, run parallel to the prevailing valley winds. Note how little snow is visible in the urbanized areas and the discoloration of snow in the surrounding area, probably due to wind-borne smoke generated by fuel burning in the city.

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Iran's Salt Glaciers



In southern Iran, the collision between the Asian landmass and the Arabian platform has folded rocks and pushed up the rugged Zagros Mountains. In places, underlying deposits of salt have ascended in fluid-like plumes. Some of these plumes have pushed through the rock above, like toothpaste from a tube, and they are now visible as darkish irregular patches. This image shows a few of over 200 similar features—called diapirs, or salt plugs—that are scattered about this part of the Zagros Mountains.

Gravity has caused the salt to flow like glaciers into adjacent valleys. The resulting tongue-shaped bodies are more than 5 kilometers long, with repeating bow-shaped ridges separated by crevasse-like gullies and with steep sides and fronts. The darker tones are due to clays brought up with the salt, as well as the probable accumulation of airborne dust. This ASTER perspective view was created by draping a band 3-2-1 (RGB) image over an ASTER-derived Digital Elevation Model (2x vertical exaggeration), and was acquired on August 10, 2001.

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Caspian Sea
ce clogs the northern end of the Caspian Sea in this true-color Aqua MODIS image from March 31, 2003. The Caspian Sea is actually a salt-water lake, albeit the largest lake in the world, covering 373,000 square kilometers (1 square kilometer=0.3861 square mile). Surrounding the Caspian Sea are five countries (clockwise from top left): Russia, Kazakhstan, Turkmenistan, Iran, and Azerbaijan.

Because the Caspian sits on considerable oil reserves, this lake is of great strategic and economic importance. Another of the Caspian´s very valuable attributes is the fact that this is where sturgeon, the source of beluga caviar, live and spawn. Unfortunately, the destruction of spawning areas and illegal fishing have had serious repercussions on the sturgeon population.

Also visible in the image are a number of fires, which are marked in red. The fires are concentrated in the fan-shaped Volga River Delta at upper left and all along the foothills of the Caucasus Mountains at middle left. These fires are likely agricultural in nature; many farmers use fire to prepare the land for spring planting.
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Dust storm across the Persian Gulf
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Credit
Jacques Descloitres, MODIS Rapid Response Team, NASA/GSFC

The mountainous terrain of western Iran appears to be diverting the previous days’ dust storms southward across the Persian Gulf. In this true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from March 28, 2003, dust is pooled in the valleys closest to the coast and the front stretches across hundreds of miles. Into the waters of the Persian Gulf (center), bright blue swirls of sediment pour in from rivers. In places the swirls appear tinged with green, which suggests some marine plant life could be present. Several thermal anomalies were detected by MODIS and are marked with red dots. In southern Iraq, these appear to be associated with oil fires, which are producing dark, thick smoke plumes. Another source of smoke and aerosols is the city of Baghdad, where massive plumes of blackish-brown smoke are streaming southward.

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Dasht-e Kevir
Image taken 10/24/2000

The Dasht-e Kevir, or valley of desert, is the largest desert in Iran. It is a primarily uninhabited wasteland, composed of mud and salt marshes covered with crusts of salt that protect the meager moisture from completely evaporating.



Dasht-e Kevir can be found on Landsat 7 WRS Path 162 Row 36, center: 34.62, 54.71.
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Konari, Iran
Image taken 2/2/2000

The Mand River and the small town of Konari nestle in the Zagros Mountains in western Iran.



Konari can be found on Landsat 7 WRS Path 163 Row 40, center: 28.87, 51.62.
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images of Spectacular Cenozoic Fault Scarps in the Mongolian and Gobi Altai

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Aerial photo and field photos of frontal thrust fault, SW side of Altun Huhey Range, Mongolian Altai



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Satellite view of Hovd Fault and SW Altun Huhey Range front, Mongolian Altai


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Field photos of SW Tsambagarav Range mountain front


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Aerial photo of faulted SW front of Tsambagarav Massif