USA News:


Discovery of many active booming dunes in
Badain-jaran desert in China




The mountains gloan every night. Do you believe that?
You can listen to the gloan of the big mountain here.
Why don't you push the following music mark?

Booming sound of Badin-jaram ( recorded Aug,1995 )

In August, 1995 the China-Japan Joint Research Group formed by the Institute of Desert Research, Chinese Academy of Sciences and Amino-town (Kyoto Pref. ) discovered many active booming dunes in a closed military base in the Badain-jaram desert. Details of the dunes and their loud sounding and self-booming activity were ascertained. The restricted access maintained a clean environment in harmony with the living structure of the desert which was constructed by the coexistence of sand, camels and human beings.

The booming sands of the desert and the singing sands on beachs face the same danger from human destruction of the environment. We need some means to monitor the situation. An unexpected finding was reported which hints at how to make clear booming sand formations from beach sand . From the similarity of both sands, it was proposed to cooperate and construct data making stations on both sites.

Because the desert is in an area remote from the main Silk-road (Fig.1) and only about 30 Mongolian nomad families with camels are living there now (over 250km from east to west), the environment has remained untouched.

Fig-1: Badain-jaran desert

There are no roads into the desert and the routes are bumpy. We cannot go to the place without camels. The point surveyed was Bojitoleganor lake district shown in Fig.2 .

Fig-2: Aproach to booming test point

In the district we tried booming-tests with about 10 men, climbing 50m high and sliding down the slope. We tested at the three points ( Fig.3 ). Each area has a small lake, and the dominate wind direction in the district is from west to east. The temperature of the sand was 65 C .

Fig-3: Three booming dunes tested

1st Point:102.29.27 E,39.36.20 N 1340m above sea level
This side is windward slope
2nd Point:102.28.18 E,39.36.09 N 1315m
This side is leeward slope
3rd Point:102.30.43 E,39.30.40 N 1385m

Booming tests and self booming
the above three point had almost the same booming character. After several seconds of sliding, great booming sounds occured (60-70dB) and continued until the men stopped at the foot of the slope. If the men stopped in the middle of the slope, the surface layer of the sand would countinue avalanching by itself and boom continuously for several minutes. The slope angle was 31 degree, total slide length on the slope was about 100m. The sound was large enough to hear from a distance of 4 Km or more. The highest sound level was found at the 2nd point. We picked up a sample of the sand at a midpoint of the slope.

In the evening strong winds made the sand slid down the dune slope, producing booming by itself. We heard the self-booming every evening from 4 Km away during our 3 day stay at the place.

The dunes have complete booming activity and they can groan without any human intervention. The fact that the sands shown in Fig.4 have such activity is clear evidence that keeping a genuine environmental condition over the desert is essential. All had very low frequency soundings (about 100Hz) and are rare examples of a complete self-purification and harmony

between natural sand dunes, the life of nomads and their camels.

Fig-4: Microphotograph of the sand

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