National Geographic : 1952 Mar
A Rima Mother Washes Her Child in a Mountain Stream Fatalistic Rima people, losing homes and stock but not their lives, resumed work in the fields immediately after the earthquake. This youngster got the usual morning bath. A ragged hemp coat is the woman's only garment. world had been jarred, calculated that the epicenter of this frightful cataclysm in August, 1950, had been along the border between Assam and Tibet, very close to our campsite on the outskirts of the Tibetan village of Rima (map, page 405). Earthquakes are frequent in this region. It lies in one of the earth's two great belts of seismic activity, which extends from the Mediterranean across southern Asia. The other encircles the Pacific Ocean.* Although little is known about possible faults or rifts in the earth's crust in this area, it is probable that the shocks which we ex perienced were associated with one or more faults, as are most earthquakes. Faults are found where mountain chains are rising, in this case the Himalayas. Indian geologists refer to one as the Great Boundary Fault at the eastern end of the Himalayas, near where Tibet, Assam, and Burma meet. As the mountains rise, rocks in the earth's crust are put under great strain. Finally the rock gives way, and, as the strain is released, there is an elastic rebound of the crust, with a rock mass on one side of a fault slipping past that on the other. The rebound Himalayas for the in London. During the past gaged in studying sets up the vibrations felt in an earthquake. Even a small amount of ground movement can cause severe damage, es pecially in a region of steep mountains where masses of rock and earth can easily be dislodged. The magnitude of this earthquake was 8.6 on the Gutenberg-Richter scale used by seismologists. It is believed to have been at normal depth, about nine miles below the earth's surface. No stronger earth shock has been recorded since the use of seismographs for measuring them became general about the turn of the century. Only one other in the past 50 years was of equal magnitude, that in Colombia in 1906. Rendezvous with an Earthquake My wife and I had traveled far to keep our unwitting rendezvous with one of the world's severest earthquakes. Our pur pose was to gather botan ical specimens high in the Natural History Museum 30 years I have been en plant life in the remote mountain core of southeast Asia. Botanically, the region we visited in 1950 is little explored, yet it is of particular interest, since the wild ancestors of many of our present food crops came originally from this part of the world. Our object was twofold: First, we wanted to make, or at least begin, a survey of the flora in this region to link it into the plant geography of Asia and the world as a whole. Second, we hoped to collect seeds of alpine plants which might prove practicable for cul tivation in western gardens.t * "Our Home-town Planet, Earth," by F. Barrows Colton, NATIONAL GEOGRAPHIC MAGAZINE, January, 1952, contains a map of these areas and discusses the causes of earthquakes. t For accounts of plant exploration and how it has enriched our gardens and orchards, see, in the NA TIONAL GEOGRAPHIC MAGAZINE: "How Fruit Came to America," by J. R. Magness, September, 1951; "Our Vegetable Travelers," by Victor R. Boswell, August, 1949; and "The World in Your Garden (Flowers)," by W. H. Camp, July, 1947.