The important reason that the measurement of Mount Qomolangma has attracted worldwide concerns this year is that there have been three unsolved and long-disputed mysteries in the world, which will probably find a clue to the answers in this measurement action, reported special correspondent Zhao Yahui from the People's Daily.

First, how high is "the roof of the world''?

In 1954, an Indian survey known as Gulatee fixed the height at 8,847.6 meters; in 1975, a Chinese expedition and mapping team found the peak was growing, standing at 8,848.13 meters; in 1992 an Italian expedition re-measured the height of the mount was 8846.50 meters; in 1999 a US expedition using GPS technology re-measured the elevation and found it to be 8,850 meters ¡­ What on earth is the height of Mount Qomolangma? It has been the subject of controversy.

China has adopted an advanced and perfect measurement scheme, namely the traditional classical measurement method and the modern GPS technology. These two kinds of methods will supplement and confirm each other, which will find a clue to the height mystery of Mount Qomolangma.

Second, how thick are the ice and snow at the summit?

Correctly measuring the thickness of the accumulated ice and snow at the summit of Mount Qomolangma peak is of important scientific significance for assessing the height changes of Mount Qomolangma as well as its impact on the change of the whole world. However there has been controversy about the thickness of the accumulated ice and snow on top Mount Qomolangma.

In 1975, a Chinese expedition and mapping team found the peak stood at 8,849.05 including the thickness of the ice and snow layers when it reached the peak and measured Mount Qomolangma. The depth of the ice and snow layers on top of the mount measured by a women team member was 0.92 meters by the way of inserting drill rod at that time. So the actual high of the peak was 8848.13 meters; in 1992, an Italian reached the peak the scientist measured the thickness of the ice and snow to be 2.55 meters by the same way. So there was 1.63-meter difference between the two measuring results made in 1975 and in 1992 respectively.

Some researchers also do not think the method by working a drill rod into the ice and snow can measure the true thickness of the ice and snow. The thickness of the ice and snow on top of Mount Qomolangma is far greater than 2.5 meters or perhaps even more than 10 meters.

This year's measurement of Mount Qomolangma is more attractive since the mountaineers carried an advanced radar detector specially made for measuring ice and snow while climbing the mount so they could more accurately survey the thickness of the floating snow and the permanent ice sheet on the peak of Mount Qomolangma by following the different responses of frequency according to the different materials there.

Third, how the earth's crust of Mount Qomolangma area and the Qinghai-Tibet Plateau changes?

Researches prove that probably 200 million years ago, the Himalayas area was a vast expanse of water. Because the Indian plate was pushed to the plate of Asia, the Himalayas and Qinghai-Tibet Plateau began to take shape, and are rising constantly. So far, Qinghai-Tibet Plateau has still been the strongest area of crustal movements on the earth.

But how the "crustal movements of Qinghai-Tibet Plateau are on'' has been the focus that the scientific circles in the world are concerned about. Thirty special points were chosen respectively in the Qinghai-Tibet Plateau and the surrounding area of Mount Qomolangma for the re-measurement this time with GPS satellite navigation for on-line observation. The observation will play an important role in studying the crustal movement details in the area of Mount Qomolangma and Qinghai-Tibet Plateau.