Seismological Observatory

The seismological observatory was founded in early 1970s to cater for the recording of earthquake signals in the Ganga foredeep. The basement depth here is approximately 3000 m below the seismological observatory. The observatory is situated near the junction of north east rock sequence of the Himalayan orogenic belt and the area is covered with quaternary alluvial deposits of the Indo Gangetic plains and is about 25 km south of Himalayan Frontal Fault. Northeast direction of crustal shortening is reported in the nearby areas. North of the Roorkee Seismological observatory lies the Ganga Tear, a conspicuous transverse fault along which nontectonic activity is evident.

Facilities

Online Time Data Acquisition (Real Time Processing)

The Seismological Observatory is receiving online data from the following projects in real time. 1. EEW system 2. DRIP Dams from Madhya Pradesh 3. DRIP dams from Uttarakhand 4. THDCIL strong motion network deployed in Tehri and Koteshwar dam 5. THDCIL seismological array of 18 stations through VSAT 6. MEQ arrays deployed from time to time by the Department of Earthquake Engineering 7. Data from Roorkee Observatory 8. Data from UDRP Project

Short-term Microearthquake Investigations

Microearthquake investigations employing temporary local networks of portable seismographs were started in 1973. Since then the Department has conducted several studies around Hydro-Electric project sites, potential geothermal zones and other important engineering project sites. A study was also carried out in Sri Lanka around the Kotmele dam site.
The purpose of these studies is to investigate the seismological conditions in the environs of proposed dam sites and to monitor the reservoir induced seismicity (RIS) along the dam in case having large reservoir such as Tehri dam. Also to locate the deep seated geothermal sources of energy. The important studies completed and are in progress are listed below.

Studies in Progress
	Tehri Dam, Uttarakhand (since 1995)
	Arun-3 , Nepal (since 2019)
	Song Dam Multipurpose water project, Uttrakhand (since 2018)
Studies Completed
	Region of Study	Year of Recording
	Puga valley, Ladakh, Jammu & Kashmir	1973, 1978
	Tehri dam site, Uttarakhand	1974, 1975
	Kalagarh dam, Uttar Pradesh	1975
	Kalawar, Yamuna, Haryana	1975, 1985
	Parbati valley, Himachal Pradesh	1977
	Sona valley, Haryana	1977
	Navegam dam, Gujarat	1976, 1980
	Jamrani dam site, Nainital, Uttarakhand	1980-81
	Kotmele dam site, Sri Lanka	1982-83
	Chemera dam, Himachal Pradesh	1983
	Tipaimukh dam site, Manipur	1991
	Muram dam site, Orissa	1992
	Kameng HE Project, Arunachal Pradesh	2002-03
	Middle Siang, Arunachal Pradesh	2004
	Kol Dam project , Himachal Pradesh	2004-18
	Lower Siang, Arunachal Pradesh	2011-12
	Lakhwar HE Project, Uttrakhand	2016
	Etalin HE Project, Arunachal Pradesh	2017
	Umangot HE Project, Meghalaya	2018

Seismic Data Acquisition for Uttarakhand State

The seismicity data acquisition is being carried out for last few decades for Uttarakhand State. The seismological observatory is in operation since 1971 at Roorkee. The analogue data was acquired through three observatories during 1975 to 1996 sponsored by UP Irrigation followed by DST funded first Digital Sample Telemetered Seismic Array successfully deployed and acquired data from 1987 to 1995. Broadband sensors were also deployed intermittently in Uttarakhand from time to time. Finally the 18 station array is being deployed by THDCIL which is acquiring data since 1995.
The Earthquake Early Warning system EEW is in place in Uttarakhand State. EEW has been deployed in Garhwal Himalaya and Kumaun Himalaya. The lead time from an earthquake in this region is estimated to be more than a minute in Delhi and about 20 seconds in Dehradun. The sirens have been deployed at public places in Uttarakhand. State.

18-station seismological network around Tehri region, Garhwal Himalaya

Research Area

Seismotectonics of Main Frontal Thrust and Indo-Gangetic Plains Around Roorkee

Research Scholar - Arup Sen
Supervisor - Prof. S. C. Gupta & Prof. A. Kumar

Tectonic uplifts in the form of Piedmont fault (PF) mapped to the south of the Main Front thrust (MFT) are interpreted to represent an emerging new plate boundary below the Indo-Gangetic Plains (IGP). In the quest of understanding the seismotectonics of the study area we elucidate the geometry of the PF and the MFT from the attributes of well-located local earthquakes, and interpret the seismotectonics beneath the IGP and the segment of the MFT, that marks the southern boundary of the Garhwal Sub Himalaya (GSH) and try to propose a seismotectonic model out of it.

Study of Intrinsic and Scattering Attenuation in the Garhwal Himalaya

Research Scholar - Sanjay Kumar Jain
Supervisor - Prof. S. C. Gupta & Prof. A. Kumar

The frequency dependent attenuation relationships have been developed for the Uttarkashi and Chamoli regions of the Garhwal Himalaya estimating the quality factor of coda waves, Qc, and S-waves, Qβ using the local earthquakes in the region recorded during 2008 and 2009 in five epicentral distance ranges through deployment of a 12-stations seismological network around Tehri region. The coda waves of 30 sec duration have been analysed in seven frequencies ranges for five lapse time windows.

Installation of 18-station network around Tehri region