نا آرامی و آشوب در در آتشفشان " توری آلبا " ، " کا ستاریکا " Unrest at Turrialba Volcano, Costa Rica

Turrialba Volcano, located in central Costa Rica, emits a translucent plume of volcanic gases in this natural-color satellite image from January 21, 2010. According to the RED Sismológica Nacional (Costa Rican National Seismological Network), activity at the volcano increased markedly on January 4, 2010. Strong, long-lasting volcanic tremors were accompanied by gas plumes over the volcano, and emissions of ash began on January 5th. The “jet-type noise” of gas and ash rushing out of fumaroles was heard several kilometers away. On January 21, Nacion.comreported that potato and carrot farmers were asked to leave fields near the volcano’s summit due to further increases in gas emissions.

The barren summit region of the 3,340-meter- (10,960-foot-) high Turrialba appears gray and brown, while the volcanic plume is a hazy blue. Fields and pastures are light green, in contrast to dark green forest that covers the high-elevation ridges. Since 2007, frequent acid rain showers caused by activity at the volcano killed or damaged much of the vegetation to the southwest of the summit, leaving the area brown and orange. This image was acquired by the Advanced Land Imager (ALI) aboard NASA’s Earth Observing-1 (EO-1) satellite.

1.   Reference

2.   Nacion.com. (2010, January 21). Suspendida agricultura cerca del volcán Turrialba. Accessed January 25, 2010.

3.   Red Sismológica Nacional. (2010, January). Turrialba Volcano, Costa Rica. Current Activity: January 4-10, 2010. Preliminary Report. Accessed January 25, 2010.

4.   Volcano Live. (2010, January). Turrialba Volcano - John Search. Accessed January 25, 2010.

پسروی یخچال ها ی قطبی Retreating Glaciers

 Satellite image of the Jakobshavn Glacier, Greenland's largest and fastest moving tidewater glacier, which is retreating under conditions similar to those Briner studied in the Canadian Arctic. NASA Landsat Geocover image.

 Study shows that Ice Sheets Can Retreat in a Geologic Instant

 Glaciers Are Capable of Rapid Retreat

Modern glaciers, such as those making up the Greenland and Antarctic ice sheets, are capable of undergoing periods of rapid shrinkage or retreat, according to new findings by paleoclimatologists at the University at Buffalo. 

The paper, published on June 21 in Nature Geoscience, describes fieldwork demonstrating that a prehistoric glacier in the Canadian Arctic rapidly retreated in just a few hundred years. 

The proof of such rapid retreat of ice sheets provides one of the few explicit confirmations that this phenomenon occurs. 

Should the same conditions recur today, which the UB scientists say is very possible, they would result in sharply rising global sea levels, which would threaten coastal populations. 

استانبول ، ترکیه Istanbul, Turkey

The population of Turkey's economic and cultural center has exploded in recent decades.

The rise and fall of empires is easy to read in Istanbul’s richly varied architecture. Stately 19th century wood townhouses are tucked in the shadow of the fifteenth century Ottoman palace. The late Roman or early Byzantineaqueduct of Constantinople cuts across the city center, a straight line across a skyline punctuated with minarets on mosques that are only centuries old. But as much as history has left its imprint on Istanbul’s make-up, modern civilization may have a far greater impact on its shape.

Istanbul has grown by more than 11 million people in the last 50 years, and the city has expanded to accommodate its new population. This pair of images contrasts Istanbul’s size in 1975 to its size in 2011. Both images come from the Landsat series of satellites and show the city in false color. Plant-covered land is red, while urban areas are gray. Lightly vegetated land or bare earth is tan, and water is black.

In 1975, Istanbul was still centered around the Golden Horn, the estuary that flows southwest into the Bosporus Strait. By 2011, the city had expanded over many kilometers to the east and west, and a new reservoir is visible to the west. Istanbul housed more than 13 million people by the end of 2011—18 percent of the population of Turkey. Much of Istanbul’s growth is happening as people move to the city for industrial jobs.

The images reveal some interesting patterns of growth. In 1973, the first bridge across the Bosporus opened, connecting the Asian side of Istanbul to the European side. The bridge is faintly visible in the 1975 image, and the urban areas in the newly connected east are near the bridge. In 1988, Istanbul opened a second bridge across the Bosporus. Farther north, this bridge is visible in the 2011 image. Not surprisingly, the dark gray of dense settlement has filled in the area between the two bridges on both sides of the strait.

This modern sprawl may be nothing new for Istanbul. Archeologists recently identified a wealthy port city some 13 miles west of Istanbul that was operating during the fourth to sixth centuries, during the founding of Constantinople. Though the find is new and not well understood, the city may have acted as a satellite harbor and retreat for the wealthy of Constantinople. The city appeared to have been abandoned after an earthquake flattened it in 1037.

1.   References

2.   Finkel, A. (2011, November 16). The bridge to nowhere. International Herald Tribune. Accessed January 27, 2012.

3.   Istanbul Metropolitan Municipality. (2008). Population and demographic structure. Accessed January 27, 2012.

4.   Pinkowski, J. (2012, January 23). After being stricken by drought, Istanbul yields ancient treasure. New York Times.Accessed January 27, 2012.

5.   Republic of Turkey Turkish Statistical Institute. (2012, January 27). The results of address based population registration system. Accessed January 27, 2012.

انفجار جمعیت در دهه ی اخیر ناشی از شرایط اقتصادی و فرهنگی در استانبول

فعالیت زبانه های خورشید The Sun Flares with Activity

Following one of the longest and weakest periods of activity in many cycles, the Sun is brimming with activity again. In late January 2012, our nearest star offered a preview of what may be to come in the solar maximum of 2012–13. The storm has the potential to disrupt some communications and satellite systems and to bring auroras to high-latitude skies.

The images above show a solar flare as observed by the Atmospheric Imaging Assembly (AIA) on NASA’s Solar Dynamics Observatory (SDO) at 03:27, 03:42, and 04:12 Universal Time (Greenwich Time) on January 23. Note the brightening of the solar surface as gas was superheated and magnetically supercharged. By the third (right) image, a stream of solar material is seen flowing off into space above the hot spot, likely solar protons and a coronal mass ejection. Click on the enlarged images and movies for a wider view.

The high-latitude solar flare was measured as M8.7 in intensity, just below the most intense “X class” of flares. The eruption sent a stream of fast-moving, highly energetic protons toward Earth, provoking the most intense solar energetic particle storm—an S3 on NOAA Space Weather Prediction Center’s scale—since 2005.

The flare was accompanied by a coronal mass ejection (CME), a cloud of solar plasma that was ejected from the solar atmosphere in the direction of Earth. The CME was observed by the STEREO and SOHO spacecraft with an initial speed of more than 2,000 kilometers (1,400 miles) per second. It was estimated to reach Earth sometime on January 24 and Mars on January 25. NOAA forecasters were predicting a G2 geomagnetic storm, though a G3 was possible.

Solar flares and CMEs are not a danger to humans on Earth's surface, as the planet's magnetic field (magnetosphere) and atmosphere deflect and absorb the solar energy and particles. The sun storms can pose some risks to astronauts, and they can upset the electronics and transmissions on science, military, and communications satellites. Closer to Earth's surface, solar activity can cause disruptions of radio signals (particularly HF), provide a small dose of radiation to passengers on high-latitude flights, and provoke auroras (northern and southern lights).

The storm is impressive by recent standards, but nowhere near the maximum intensities often generated at the height of the solar cycle. “I would expect that we will see more storms like this one or even bigger as we get closer to solar maximum,” said Michael Hesse, chief of heliophysics at NASA’s Goddard Space Flight Center.

در یکی ار دوره های فراز و فرود زبانه های خورشید هستیم که  بار دیگرجنبایی از سر گرفته است . در اواخر ژانویه ی 2012 ، نزدیکترین ستاره بما ، بیان از حداکثرفعالیت های  خورشید دارد . در سال های 2012 -2013 توفان  سبب اختلالات در ارتباطات و ماهواره ها و ایجاد ریز گرد ها در آسمان عرض های بالایی خواهد شد .

آتش و یخ در آتشفشا ن ِ " کی زی من" Fire and Ice at Kizimen Volcano

The low-in-the-sky winter sun casts extraordinarily long shadows in this satellite image of Russia’s Kizimen Volcano. A light-colored plume, likely steam-rich, rises above Kizimen’s summit, while a growing lava flow (mostly hidden by gases) descends the eastern flank. Emissions of ash, lava, and volcanic gases have been nearly continuous since the eruption started in November 2010.

This false-color image was acquired on January 11, 2012, by the Advanced Spaceborne Thermal Emission and Reflection Radiometer aboard the Terra satellite. Snow covers the landscape at high altitudes, and the evergreen forests to the north of the volcano are dark red-brown. The light brown hills nearby are covered with leafless deciduous trees poking above the snow.

1.   Reference

2.   Kamchatka Volcanic Eruption Response Team. (2012, January 12). KVERT Information Releases. Accessed January 13, 2012.

تولد جزیره ای آتشفشانی در دریای سرخ A Newborn Volcanic Island in the Red Sea

A volcanic eruption in the Red Sea appears to have stopped, leaving behind a newborn island. The new island is part of the Zubair Islands, located about 60 kilometers (40 miles) off the coast of Yemen. The Advanced Land Imager (ALI) aboard the Earth Observing-1 (EO-1) satellite acquired this natural-color image on January 15, 2011.

1.   References

2.   Gass, I.G., Mallick, D.I.J., Cox, K.G. (1973). Volcanic islands of the Red Sea. Journal of the Geological Society, 129(3), 275–309.

3.   Klemetti, E. (2011, December 19). Potential eruption off the coast of Yemen. Eruptions. Accessed December 27, 2011.

دلتای رودخانه ی زرد Yellow River Delta

China’s Huang He (Yellow River) is the most sediment-filled river on Earth. Flowing northeast to the Bo Hai Sea from the Bayan Har Mountains, the Yellow River crosses a plateau blanketed with up to 300 meters (980 feet) of fine, wind-blown soil. The soil is easily eroded, and millions of tons of it are carried away by the river every year. Some of it reaches the river’s mouth, where it builds and rebuilds the delta.

The Yellow River Delta has wandered up and down several hundred kilometers of coastline over the past two thousand years. Since the mid-nineteenth century, however, the lower reaches of the river and the delta have been extensively engineered to control flooding and to protect coastal development. This sequence of natural-color images from NASA's Landsat satellites shows the delta near the present river mouth at five-year intervals from 1989 to 2009.

Between 1989 and 1995, the delta became longer and narrower along a southeast-bending arc. In 1996, however, Chinese engineers blocked the main channel and forced the river to veer northeast. By 1999, erosion and settling along the old channel caused the tip of the delta to retreat, while a new peninsula had formed to the north.

The new peninsula thickened in the next five-year interval, and what appears to be aquaculture (dark-colored rectangles) expanded significantly in areas south of the river as of 2004. By 2009, the shoreline northwest of the new river mouth had filled in considerably. This may be the outcome that the engineers were anxious to achieve: the land northwest of the newly fortified shoreline is home to an extensive field of oil and gas wells. Their protection is a primary concern.

Although levees, jetties, and seawalls allow officials to slow erosion and direct the 

flow of the river, other challenges to protecting the delta’s natural wetlands and its agricultural and industrial development remain. Water and sediment flows to the delta have declined dramatically since the 1970s, due to both reduced rainfall and explosive urban and agricultural demand for water upstream. In the 1990s, the river frequently ran dry well before reaching the delta.

These low- and no-flow periods are a huge problem in the lower reaches of the river and the delta. They severely damage wetlands and aquaculture and worsen the river’s already severe water pollution problem. Ironically, they also increase the flood risk because when flows are low, sediment fills in the riverbed. The river becomes shallower and higher in elevation. In places, the river is already perched above the surrounding floodplain by as much as 10 meters (30 feet). A levee breach during a high water event could be devastating.

1.   References

2.   Baosheng, W., Zhaoyin, W., and Changzhi, Li. (2004). Yellow River Basin management and current issues. Journal of Geographical Sciences, 14, supplement, 29-37.

3.   Chu, Z., Sun, X., Zhai, S., and Xu, K. (2006). Changing pattern of accretion/erosion of the modern Yellow River (Huanghe) subaerial delta, China: Based on remote sensing images. Marine Geology,227, 13-30.

4.   Li, S., Wang, G., Deng, W., Hu, Y., and Hu, W. (2009). Influence of hydrology process on wetland landscape pattern: A case study in the Yellow River Delta.Ecological Engineering, 35, 1719-1726.

5.   Liu, J.P., Milliman, J., Gao, S., and Cheng, P. (2004). Holocene development of the Yellow River’s subaqueous delta, North Yellow Sea. Marine Geology, 209, 45-67.

6.   Xue, C. (1993). Historical changes in the Yellow River delta, China. Marine Geology,113, 321-329.

شهر نشینی " دوبی " . تبدیل به شهر شدن ِ " دبی" Urbanization of Dubai

Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite observed its progress from 2000 to 2011.

In these false-color images, bare ground appears brown, vegetation appears red, water appears dark blue, and buildings and paved surfaces appear light blue or gray. The first image, acquired in November of 2000, shows the area prior to the island’s construction. The image from February 2002, shows the barest beginnings of the artificial archipelago. By October 2002, substantial progress had been made on Palm Jumeirah, with many sandy “palm fronds” inside a circular breakwater.

By November 2003, the palm tree has been constructed, and buildings and vegetation populate Palm Jumeirah in the images from November 2004, October 2005, September 2006, March 2007, and November 2008. The final image, acquired in February 2011, shows vegetation on most of the palm fronds, and numerous buildings on the tree trunk.

Inland, changes are just as dramatic between November 2000 and February 2011. In the earliest image, empty desert fills the lower right quadrant of the image, as cityscape primarily hugs the coast. As the years pass, urbanization spreads, and the final image shows the area almost entirely filled by roads, buildings, and irrigated land.

·      References

·      Earth Observatory. (2006, October 22). Palm Islands, Dubai. Accessed April 23, 2009.

·      Van Oord. The Making of: Palm Jumeirah, Dubai. Accessed April 23, 2009.

·      Wikipedia. (2009, April 18). Palm Islands. Accessed April 23