|NASA Photo ID||ISS050-E-29426|
|Time taken||12:30:56 GMT|
1000 x 666 pixels 540 x 360 pixels 4000 x 2662 pixels 720 x 480 pixels 4928 x 3280 pixels 640 x 426 pixels
|Nikon D4 Electronic Still Camera|
|4928E: 4928 x 3280 pixel CMOS sensor, 36.0mm x 23.9mm, total pixels: 16.6 million, Nikon FX format|
|1000 pixels||666 pixels||No||No||Earth From Space collection||Download Image|
|540 pixels||360 pixels||Yes||No||Earth From Space collection||Download Image|
|4000 pixels||2662 pixels||No||No||NASA's Earth Observatory web site||Download Image|
|720 pixels||480 pixels||Yes||No||NASA's Earth Observatory web site||Download Image|
|4928 pixels||3280 pixels||No||No||Download Image|
|640 pixels||426 pixels||No||No||Download Image|
This photograph of the central Meidob Volcanic Field was taken by an astronaut onboard the International Space Station. The entire field covers an area of approximately 5,000 square kilometers (approximately 1,930 square miles) of western Sudan. There are numerous vents (nearly 700) that are believed by geologists to be less than 6 million years old. The most recent eruptive activity in the field has been dated to within 500 years of 2950 BCE, or roughly spanning the time of the unification of the Upper and Lower kingdoms of ancient Egypt.
While the majority of the Meidob field is comprised of volcanic rocks with significant iron and magnesium (basalt), the central region depicted here is dominated by volcanic rocks that have relatively higher amounts of sodium and potassium than basalt (known as trachyte and phonolite to geologists). This part of the volcanic field is also distinctive for the landforms that are common here, such as explosively-formed maar craters, lava domes built by viscous lava flows, and scoria or cinder cones formed around a single volcanic vent.