Month: September 2016

Seismically susceptible regions in the western Himalaya identified by a team from IIT Roorkee

earthquake regions

The western Himalaya experiences a considerable number of earthquakes of varying magnitudes; the most well-known one being the 1905 Kangra earthquake. Different regions in the western Himalaya –comprising the states of Jammu & Kashmir, Himachal Pradesh and Uttarakhand –are known to exhibit varying degrees of seismicity.  Thus, in order to have a better disaster management system and for improved disaster mitigation, it becomes necessary to differentiate the seismically more-vulnerable regions from the less-vulnerable ones.

A group from the Department of Earthquake Engineering, IIT Roorkee, has identified seismically susceptible areas in the western Himalaya. Profs Mridula, Amita Sinvhal and Hans Raj Wason have shown that most of Himachal Pradesh and Uttarakhand and a few regions of Jammu & Kashmir, Punjab, Uttar Pradesh and Haryana are at the greatest risk. Most of Jammu & Kashmir was found to be only moderately susceptible, while the Indo-Gangetic plains appeared to be the least susceptible. Their findings have shown that several earthquake zones categorised in the ‘seismic zoning map’ by the Bureau of Indian Standards need to be reworked.

For this study, they used the technique of ‘pattern recognition’. Simply put, PR technique, is a form of machine learning that relies on various available tectonic and seismology data of the region. The data was sourced from seismic events that have occurred beginning from the year 1552. The data needed to be appropriately and accurately categorised based on a set of parameters (such as the magnitude of the earthquakes and various features of the earth’s landscape) and fed into the system. The PR technique can then predict future earthquakes based on the recognition of existing patterns.

“This study allowed us to identify and narrow down areas where most recent earthquakes are originating, and also where strong earthquakes may recur. These results can contribute to improving the characterisation of seismic sources for seismic hazard assessment,” the scientists state in their study.

The work is published in the Journal of Earth System Science in June 2016. Link here.

Special Issue On HIGGS PHYSICS In Pramana – Journal Of Physics

Higgs1

From the discovery of the Higgs Boson, to how supersymmetry solves the Naturalness Problem, to research on electroweak phase transitions and related phenomena such as cosmological baryogenesis, electroweak bubble dynamics, generation of gravitational waves, etc., the latest edition of Pramana – Journal of Physics covers, in a latitudinarian manner, a spectrum of discussions on the current standing of the field of particle physics.

As described in the preface of the journal’s special issue on Higgs Physics, the review articles seek to answer questions such as the following:

  • Is the discovery of the 125 GeV resonance at the LHC suggestive of a new physics beyond the Standard Model?
  • If the discovery was indeed that of a Higgs boson as described by the Standard Model, then what keeps it light and protected from large quantum corrections?
  • What do this discovery and its associated theoretical investigations tell us about other questions on symmetry breaking?
  • If the discovered particle is only approximately the SM Higgs, then is the electroweak breaking mechanism driven by an extended scalar sector? (This becomes relevant, especially when considering the purported excess in the γγ final state at 750 GeV).
  • Is new physics (at the few TeV scale), then, well-approximated by a simple two-Higgs doublet model or should we consider more elaborate structures such as the minimal supersymmetric SM?

In the pursuit of the solutions to these questions and their like, however, the September 2016 issue of Pramana raises other, rather compelling, ones. Access the full articles here.