Translate

Advertiesment

Earthguake in himachal pradesh

-
The seismic sensitivity of the state of Himachal Pradesh is very high as over the years a large number of damaging earthquake has struck the state and its adjoining areas. Seismically it lies in the great Alpine Himalayan belt running from Alps Mountain through Yugoslavia, Turkey, Iran, Afghanistan, Pakistan, India, Nepal, Bhutan and Burma. Due to its location the state experiences dozens of mild earthquakes every year. Large earthquakes have occurred in all parts of Himachal Pradesh, the biggest being the Kangra earthquake of 1905. The Himalayan Frontal Thrust, the Main boundary Thrust, the Krol, the Giri, Jutogh and Nahan thrusts are some of the tectonic features that are responsible for shaping the present geophysical deposition of the state. The seismic vulnerability of Himachal Pradesh is primarily attributed to northward movement of Indian plate and to the major dislocation tectonic features such as MBF, MBT, Punjab thrust and MCT etc. Besides the longitudinal tectonic feature trending parallel to the Himalayas there are a large number of transverse fractures, faults that have been responsible for the seismic activity in the Himalayan region in general and Himachal Pradesh in particular. The Kinnaur earthquake of 1975 was associated with transverse Kauirik fault. In fact about 250 earthquakes with magnitude 4 and 62 earthquake having magnitude of 5 and above have impacted the state so far. It is also pertinent to note that the state of Himachal Pradesh is not only highly sensitive from the earthquake point of view but the risk has also grown manifold as the population and infrastructure have increased considerately over the last 20 years. Chamba, Kullu, Kangra, Una, Hamirpur, Mandi and Bilaspur Districts lie in Zone V i.e. very high damage risk zone and the area falling in this zone may expect earthquake intensity maximum of MSK IX or more. The remaining districts of Lahaul and Spiti, Kinnaur, Shimla, Solan and Sirmour lie in Zone lV i.e. the areas in this zone are in high damage risk with expected intensity of MSK VIII or more. The spatial distribution and district wise history of past seismic events is given as below.

Comments

Post a Comment

Advertiesment

Popular posts from this blog

Geology and geomorphology of himachal Pradesh

-
Himachal Pradesh with its complex geological structures presents a complicated topography with intricate mosaic of mountains ranges, hills and valleys. Composed of recent Alluvium, Shiwalik hills are made up of rocks such as sandstone, shale and clay that came into existence during the Eocene, Miocene and Pliocene period. The central part that extends from Chamba district in the north to Shimla district in the south is mainly represented by Jatog group of rocks which originated in middle Proterozoic period. In the north eastern portion unclassified Granites borders the central part in between Kullu, eastern Shimla, LahaulSpiti and parts of Kinnaur district. The eastern greater Himalaya presents the Triassic formation which is found in Kaza tehsil of LahaulSpiti district. The oldest rocks are Granites found at Jeori-Wangtu and Bandel near Largi in Kullu district. These granites date back to a stage of the crust at a time when India was located 8000 Km southwest of its present position....
Read more

Landslides in himachal pradesh

-
Image
" Landslide is the most common hazard in Himachal Pradesh, which causes immense risk to life and property. Almost every year the state is affected by one or more major landslides affecting the society in many ways. Loss of life, damage of houses, roads, means of communication, agricultural land, are some of the major consequences of landslides. The fragile nature of rocks forming the mountains, along with the climatic conditions and various anthropogenic activities has made the state vulnerable to the Landslides. District wise landslide vulnerability in the State is as follows.Triggering of landslides is both a natural and anthropogenic phenomena. As in other parts of Himalayas the landslide activity in Himachal Pradesh also varies with altitude, geology and topography. Various geophysical factors such as steepness of slopes, saturation by heavy rains, melting snow and ice, rock vibrations, excess load from embankments, fills, waste & debris dumps change in water content, f...
Read more

Floods in himachal pradesh

-
c) Floods:Floods are another form of natural disaster the State experiences every year. South west Monsoonal rainfall during the months of June to August is the dominant cause for triggering floods when rainfall happens to be in excess i.e. 125% or more than the normal. Fig 2.5 shows the percentage frequency of excessive rainfall and successive years of excessive rainfall during the period from 1951 to 1999. During this period the Chamba district in the north western part of the state had received highest amount of rainfall expressed as percentage of the normal with more numbers of successive years of excessive rainfall. Table 2.11 gives the district wise excessive rainfall years and highest annual rainfall expressed as percentage of normal and Table 2.12 gives successive years of excessive rainfall. Fig 2.6 is the map of flood prone areas as prepared by Dr D.D Sharma of H.P University Shimla. Flash Flood:Flash flood is the most frequent and damaging floods that occur with little or ...
Read more

Advertiesment