The short- and immediate-term prediction of the 1995 Menglian earthquake (M=7.3) and the social response capacities

Ronghui Lin
Seismological Bureau of Yunnan Province, Kunming 650041, China. Tel: +86-871-3312339, Fax: +86-871-3315049,
E-mail: ydj@public.km.yn.cn

Yunnan Province is one of the seismically active provinces in China. In a period of 6 months and more, there occurred three large events in Yunnan and its border area: the July 12, 1995 Menglian M7.3; the Oct. 24, 1995 Wuding M6.5; and the Feb. 3, 1996 Lijiang M7.0 earthquake. In this paper, a brief account of the three events is made, with emphasis laid on the predictions and social response capacities against the 1995 Menglian earthquake.

In 1956, the first seismic station was set up in Yunnan. Now, four decades later, the province is covered by 29 professional stations (run by the Seismological Bureau of Yunnan Province, YSB in short), 54 local stations (run by the Seismological Offices at the levels of prefecture and county) and 38 telemetered stations centring Kunming, with a capacity of monitoring a M2.5 event. In addition, 13 different kinds of precursory phenomena are observed in Yunnan at 55 fixed stations (with 300 and more different sets of instruments in total). Based on foreshocks and anomalous precursors successful predictions were made for the 1995 Menglian event, in the intermediate term (> 1 year), short term (2 months) and immediate term (1 day before the event).

To live up to the task for disaster prevention and mitigation set up by the State Council, the document entitled "Technical Countermeasures and Social Response" was published by YSB in 1986. Later on, the "Strategy for the Immediate Response to the Destructive Event" was issued by the Yunnan Provincial People's Government in 1993, in which obligations, responsibilities and requirement for the departments concerned and their leading bodies at all levels are clearly described. Together with the wide-spread, deep-going education among the public, the social response capacities were up-graded during the 1995 Menglian event. Taking Menglian county (with a population of 105,435) for example, it was stricken with intensity VIII and VII but only 11 people were killed and 136 injured. Compared with an equivalent event in the area of similar settings and conditions the death toll was reduced by 1,5002,000 at least.