Four Erupting Volcanoes on the Kamchatka Peninsula

Russia’s Kamchatka Peninsula has the highest concentration of active volcanoes on Earth. Separated by only 180 kilometers (110 miles), Shiveluch, Bezymianny, Tolbachik, and Kizimen were all erupting simultaneously on January 11, 2013.

The activity of these four volcanoes was captured during a single orbit by the Advanced Spaceborne Thermal Emission and Reflection Radiometer on NASA’s Terra satellite. These four false-color (near infrared, red, and green) images show Shiveluch, Bezymianny, Plotsky-Tolbachik, and Kizimen in detail.

The Shiveluch and Bezymianny eruptions are both characterized by a growing lava dome—thick, pasty lava that forms a mound as it is extruded. Tolbachik, one of the few shield volcanoes on Kamchatka, is erupting in a dramatically different manner. The thin, runny lava flows easily, forming low and broad flows similar to those in Hawai’i. In this image the lava remains hot enough to glow in near-infrared light.

Kizimen’s lava is not as viscous as that at Shiveluch and Bezymianny, but not as fluid as Tolbachik’s. The intermediate lava forms thick, blocky flows bordered by tall levees. Rocks and ash frequently fall from Kizimen’s summit and the fresh lava flow on its eastern flank, creating dark, fan-shaped debris deposits.

1.  References

2.   Kamchatka Volcanic Eruption Response Team. (2013, January 17) Kamchatka and the Northern Kuriles volcanoes: Erupting or Restless. Accessed January 18, 2013.

3.   Klemetti, Erik. (2013, January 18) Four New Cinder Cones from the Ongoing Tolbachik Eruption in Russia. Accessed January 18, 2013.

NASA image by Robert Simmon, using data from the NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team. Caption by Robert Simmon.

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Terra - ASTER

Dust Storm over Iran and Pakistan

A dust storm that arose on January 11 spread toward the south and east the next day. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this natural-color image on January 12, 2013.

By the time MODIS captured this scene, the dust stretched from the coast of Pakistan to the Strait of Hormuz. Thick enough to hide the ground below, a river of dust flowed southward past the Dasht-e Lut (Desert of Emptiness) in southeastern Iran. West and south of that desert, mountain ridges poked above the low-lying dust.

Dust storms rank among the leading natural hazards in Iran. Other than the subtropical climate of the Caspian Sea coast, Iran is mostly arid or semiarid. Less than 10 percent of the country’s land is arable.

1.  References

2.   CIA World Factbook. (2013, January 2) Iran. Accessed January 14, 2013.

NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response. Caption by Michon Scott.

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Dust Storm in Iran

On January 11, 2013, a dust storm struck Iran’s Dasht-e Kavir, or Kavir Desert. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image the same day. Dust plumes blew eastward, many of them arising from discrete source points.

In eastern Iran, dust plumes blew southward, passing over the diverse terrain of the Dasht-e Lut in the southeastern part of the country. (The dust plumes in eastern Iran can be seen in the high-resolution image.)

Situated on the Iranian Plateau, southeast of Tehran, Dasht-e Kavir is known as the Great Salt Desert. The plateau’s landscapes include gravel plains, sand dunes, small streams, and salt flats. Dasht-e Kavir typically sees less than 100 millimeters (4 inches) of precipitation a year, and the region has no major water bodies. It is considered one of the hottest places on Earth. This area lies within a broad band of prolific dust-producing land stretching from the Sahara Desert in the west to the Gobi Desert in the east.

1.  References

2.   Freshwater Ecoregions of the World. (2012, August 18) Kavir and Lut Deserts. Accessed January 14, 2013.

3.   University Corporation for Atmospheric Research. Forecasting Dust Storms. (Registration required).

NASA image courtesy Jeff Schmaltz, LANCE MODIS Rapid Response. Caption by Michon Scott.

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Pollution across Southwestern Asia

Cold winter weather and burgeoning industrial economies have made for difficult breathing in Asia and the Middle East this January. News reports from Ankara, Tehran, Beijing, and other cities have described hazy skies with very low visibility; restrictions on driving, factory operations, and outdoor activity; and hospitals full of people with lung ailments.

The map above shows the concentration of nitrogen dioxide (NO₂) in the atmosphere above southwestern Asia from January 1–8, 2013. Shades of orange reflect the relative abundance of NO₂, while grays show areas without usable data (cloud cover, for instance). The data were acquired by the Ozone Monitoring Instrument (OMI) on NASA’s Aura satellite. OMI measures the visible and ultraviolet light scattered and absorbed by Earth’s atmosphere and surface. The presence of NO₂ causes certain wavelengths of light to be absorbed.

Nitrogen dioxide is a key emission from the burning of fossil fuels by cars, trucks, power plants, and factories; the combustion of fuel also produces sulfur dioxides and aerosol particles. When the weather is hot and sunlight strongest, NO₂ emissions usually lead to the creation of ground-level ozone. In the winter, NO₂ is less likely to breed ozone, but it does linger for a long time and contribute to fine particle pollution. Year-round, it is a good proxy for the presence of air pollution.

Reports from Tehran and other cities note that the air is full of particulate matter, which is easier to spot from the ground but harder to measure from space. Desert landscapes, snow cover, and clouds all make airborne particles difficult to measure with nearly all current satellite instruments. Given that aerosols and NO₂ usually arise from the same fuel-burning emissions, the presence of one usually indicates the presence of the other.

In winter, several trends can combine to significantly harm air quality. When the weather is cold, people burn more fuel to keep warm. In many developing economies, the most widely available fuel is coal, which can produce more particulates and smog-producing compounds than other forms of energy.

At the same time, the weather is conspiring to keep these emissions close to the ground. In most times of year, the air higher in the atmosphere is cooler than the air near the ground, allowing warm air to rise and carry pollution up and away from its source. But in the winter, temperature “inversions” can form, where the air near the ground is cooler than the air at altitude. Polluted surface air rises a bit, but then runs into warmer air masses above and stays trapped near the surface.

Winter also can bring strong high pressure systems, which generate less wind and more stable atmospheric conditions that also hold surface air in place. Even geography can concentrate the air pollution. If a city is surrounded by mountains, cold air may continually sink down into the basin and the hills may temper or redirect the winds that can clear the air.

1.  Related Reading

2.   Hurriyet Daily News (2013, January 17) Alarming air pollution in Ankara. Accessed January 17, 2013.

3.   NASA Earth Observatory (2007, May 20) Driving Ban Lowers Beijing Pollution.

4.   The New York Times (2013, January 6) Annual Buildup of Air Pollution Chokes Tehran. Accessed January 17, 2013.

5.   U.S. Environmental Protection Agency (n.d.) Nitrogen Dioxide. Accessed January 17, 2013.

NASA Earth Observatory image by Jesse Allen, using data provided courtesy of the Aura OMI science team. Caption by Michael Carlowicz.

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Dust Storm in Western Africa

Dust plumes blew off the west coast of Africa and over the Atlantic Ocean on December 28, 2012. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image the same day. Multiple plumes blew westward, some arising near the coast, and some arising east of the Western Sahara-Mauritania border.

Sandy desert extends over parts of Western Sahara and most of Mauritania. Hot, dust-choked sirocco winds rank among the leading natural hazards of both countries, according to the CIA World Factbook. The winds often arise during the winter and spring.

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