China Fears Mt. Qomolangma Is Shrinking
China is to re-measure the world's tallest peak, Mount Qomolangma, because of fears it maybe shrinking. A recent survey found the summit had dropped by l.3 m (4 ft) because of global warming. The height of the mountain, which lies on the border between China and Nepal, has long been a subject of controversy. It was first measured in the 1850s, but a more accurate Indian survey 100 years later calculated the mountain to be 8,848m tall. In 1999, American scientists re-measured the mountain using global positioning satellite technology. They - and the National Geographic Society - concluded that the peak was two meters higher. But now global warming is melting glaciers on the world's highest mountain, apparently causing it to shrink. Chinese scientists will map Qomolangma in March to check estimates that it is more than one meter shorter than before. No matter how big it really is, Mount Qomolangma's height is unlikely to stay constant. The movement of the earth's tectonic plates is forcing the Himalayas upwards, reportedly causing Qomolangma to grow by about one centimeter every year.
A volcano's power, drawn from deep within the earth, is unleashed in different forms, from molten lava to thick clouds of burning gas to blazing rocks, falling from the sky. All over the world, people choose to make their homes in the path of nature's deadly power. Nowhere is the relationship between alluring scenery and terrifying danger more tenuous than in southern Italy - at the site of Mount Vesuvius, the world's most famous volcano.
Rising four thousand feet above the Bay of Naples, Mount Vesuvius looms above the Italian countryside, Today, millions live at its base. Every day these Italians accept the risk of living next to this ticking bomb. But Vesuvius' explosive potential wasn't always evident to those who lived nearby.
Vesuvius was not really known to be an active volcano by the Romans at first. They had no real history of its volcanic activity. In early August, 79AD, sporadic tremors rocked the Campanian plains. Wells dried up and water disappeared from streams. These were all signs that gas pressure was growing inside the volcano. Then, at about one P. M. on August 24th, the floor of the crater cracked, and Mount Vesuvius roared to life. The earliest fatalities from the eruption were probably because of people being hit by rocks and also by being buried under roof collapses. Around midnight, the eruption column collapsed, behaving like a fountain of ash and pumice, and cascading down at a very high speed and flowing like an avalanche of snow, but in this case a very hot avalanche of hot ash. This pyroclastic flow(火山灰流) is a volcano's most lethal weapon. As many as twenty thousand people perished in the eruption.
Then the volcano erupted again in 4.72 AD and then in 1631.More eruptions were recorded in the 18th and 19th centuries. On March 13th, 1944, an explosion inside the vent caused rocks and boulders to fall into the cone, completely closing the vent, Lava and gases were now trapped and the pressure inside was building. An eruption was now more likely than ever.
At 4: 30 PM on March 18th, a powerful explosion within Mount Vesuvius drove lava over the crater's rim. Wide strips of liquid fire burned on the slopes of the mountain. The lava is practically molten rocks that flow along the flank of the volcano like a river. The eruption of 1944 claimed twenty-six lives. Thousands of people were evacuated. The entire countryside was a barren wasteland.
Today, Mount Vesuvius has been calm for more than fifty years. During this period, magma has been sitting in its reservoir, undergoing chemical changes - a process that could lead to another eruption. The longer the magma sits around in the reservoir and stews in there and differentiates or evolves, the greater the potential of a large, catastrophic eruption. We are not sure when it will happen next time, but we do know that after long periods of rest, the next eruption will be devastating. Some believe the disaster could be even greater than the one that occurred in 79AD. The high population density does not help matters, as a string of towns and villages circle the slopes of the volcano bringing the population to over a half million people. But to those who live at the foot of Mount Vesuvius, this is the power of nature and it help us get a better understanding of our position on planet Earth.