Wednesday, August 23, 2006

Face Ground reality
Seismology is a multi-disciplinary subject that holds immense scope for earth scientists and professionals from the fields of computers, physics, electronics, telecom and civil engineering.
Sandeep Manudhane

Sudden, and sometimes, catastrophic movements on the earth’s surface generally result from the release of elastic strain energy that radiates seismic waves. Earthquakes typically result from the movement of faults, planar zones of deformation within the earth’s upper crust.

Seismology (derived from the Greek word ‘seismos’ meaning “earthquake” and ‘logos’ meaning “word”) is the scientific study of earthquakes and the movement of waves through the earth. The field also includes studies of variants such as sea quakes, volcanoes and plate-tectonics, and consequential phenomena, such as the dreaded tsunamis and their like.

Earthquakes (and other earth movements) produce different types of seismic waves. These waves travel through rock, and provide an effective way to “view” events and structures deep inside the earth.

The process of mapping sub-surface features is a specialty called seismography. Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are recorded on seismographs. Seismic waves produced by explosions have been used to map salt domes and other oil-bearing rocks, faults (cracks in deep rock), rock types, and long buried giant meteor craters.

Earthy approach

 Seismologists are earth scientists specialising in geophysics, who study the genesis and the propagation of seismic waves in geological materials. These geological materials can range from a laboratory sample to the earth as a whole, from its surface to its core. Their research aims at interpreting the geological composition and structures of the earth. In the case of earthquakes, seismologists evaluate potential dangers and seek to minimise their impact through the improvement of construction standards.

A vast majority of seismologists work in petroleum exploration, where the seismic waves come from controlled sources (explosions, vibrations caused by trucks).

The generated seismic waves make it possible to locate the geological structures at a depth. Other seismologists study the seismic waves generated by much more powerful sources: natural causes like earthquakes and mining events, or artificial ones like underground nuclear tests. The fundamental work of a seismologist is to locate the source, the nature and the size (magnitude) of these seismic events.

The study of earthquakes involves several specialities . Seismologists may either study the relation between faults, stress and seismicity (i.e. seismo-tectonics). Others may interpret the mechanism of rupture from seismic wave data (focal mechanisms), or integrate geo-scientific information in order to define zones of seismicity (seismic zoning), or collaborate with engineers in an attempt to minimise the damage caused to structures (earthquake engineering).

This field of seismology is multi-disciplinary, involving earth scientists, as well as technicians and professionals from the fields of computers, physics, electronics, telecommunications and civil engineering. Contacts with emergency organisations are often necessary.

Areas of study

Depending on their field of interest, seismologists can come from the following fields: geology, geophysics or applied mathematics. A university undergraduate degree is necessary, and Master’s studies or doctoral work are significant assets for more advanced research.

One has to study the causes of earthquakes, seismology, seismology of India, hazard analysis, dynamics of continuous media, response spectrum analysis, design strong motion, ground respond analysis, liquefaction, seismic slope stability, retaining wall system design, dynamic properties of soils, ground improvement systems, etc

Most students proceed to a research role in government, industry, or university. Employment prospects following the course are excellent: students with such skills are in high demand.

Jobs galore

The Ministry of Human Resource Development (MHRD), Government of India, has launched the National Programme on Earthquake Engineering Education (NPEEE). Its aim is to build capacity in our technical institutions, particularly engineering colleges, in the subject of earthquake engineering. Several short-term courses in the coming years are planned all over the country to meet this objective.

The IISc, Bangalore, one of the resource institutions participating in the NPEEE, conducts a short-term course for engineering college teachers.

A career in seismology can be quite rewarding since predicting calamities before time can help save many lives and prevent unnecessary damages. It is a challenging job and will prove to be a success in the coming years.

Training talk

  • IIT Kharagpur, Kharagpur ( M.Tech in computation seismology).

  •  Department of Earthquake Engineering, IIT, Roorkee.

  • Department of Geophysics, BHU, Varanasi

  • Wadia Institute of Himalayan Geology, 33, Gen. Mahadeo Singh Road, Dehra Dun

  • GIS Institute, G-4, Sector- 39, Noida.

(The list is not exhaustive)

The writer is Managing Director, PT Education.