Modelling for Science, for a better future - some recent outcomes
Seismic hazard and probability assessment of Kashmir valley, northwest Himalaya, India
by Rakesh Chandra, Javid Ahmad Dar, Shakil Ahmad Romshoo, Irfan Rashid, Imtiyaz A. Parvez, Sareer Ahmad Mir and Midhat Fayaz
Seismic hazard analysis of the northwest Himalayan belt was carried out by using extreme value theory (EVT). The rate of seismicity (a value) and recurrence intervals with the given earthquake magnitude (b value) was calculated from the observed data using Gutenberg–Richter Law. The statistical evaluation of 12,125 events from 1902 to 2017 shows the increasing trend in their inter-arrival times. The frequency–magnitude relation exhibits a linear downslope trend with negative slope of 0.8277 and positive intercept of 4.6977. The empirical results showed that the annual risk probability of high magnitude earthquake M ≥ 7.7 in 50 years is 88% with recurrence period of 47 years, probability of M ≤ 7.5 in 50 years is 97% with recurrence period of 27 years, and probability of M ≤ 6.5 in 50 years is 100% with recurrence period of 4 years. Kashmir valley, located in the NW Himalaya, encompasses a peculiar tectonic and structural setup. The patterns of the present and historical seismicity records of the valley suggest a long-term strain accumulation along NNW and SSE extensions with the decline in the seismic gap, posing a potential threat of earthquakes in the future. The Kashmir valley is characterized by the typical lithological, tectono-geomorphic, geotechnical, hydrogeological and socioeconomic settings that augment the earthquake vulnerability associated with the seismicity of the region. The cumulative impact of the various influencing parameters therefore exacerbates the seismic hazard risk of the valley to future earthquake events.
Source: https://link.springer.com/article/10.1007/s11069-018-3362-4
Moisture Supply from the Western Ghats Forests to Water Deficit East Coast of India
by Supantha Paul, Subimal Ghosh, K. Rajendran and Raghu Murtugudde
The mountainous western coast of India, known as the Western Ghats [WG], is considered to be a bio‐diversity hotspot but it is under a constant threat due to human activities. The region is characterized by high orographic monsoon precipitation resulting in dense vegetation cover. Feedback of such a dense vegetation on the southwest monsoon rainfall is not yet explored. Here we perform regional climate simulations with the Weather Research and Forecasting model and find that Evapo‐Transpiration [ET] from the vegetation of WG contributes 25‐40% of the southwest monsoon rainfall over the water‐deficit state of Tamil Nadu. This contribution reaches 50% during deficit monsoon years or dry spells within a season. Our findings suggest that recent deforestation in this area will not only affect the biodiversity of the region but also the water availability over Peninsular India, which is already impacted by water scarcity.
Source: https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GL078198
India plate angular velocity and contemporary deformation rates from continuous GPS measurements from 1996 to 2015
by Sridevi Jade, T. S. Shrungeshwara, Kireet Kumar, Pallabee Choudhury, Rakesh K. Dumka and Harsh Bhu
We estimate a new angular velocity for the India plate and contemporary deformation rates in the plate interior and along its seismically active margins from Global Positioning System (GPS) measurements from 1996 to 2015 at 70 continuous and 3 episodic stations. A new India-ITRF2008 angular velocity is estimated from 30 GPS sites, which include stations from western and eastern regions of the plate interior that were unrepresented or only sparsely sampled in previous studies. Our newly estimated India-ITRF2008 Euler pole is located significantly closer to the plate with ~3% higher angular velocity than all previous estimates and thus predicts more rapid variations in rates and directions along the plate boundaries. The 30 India plate GPS site velocities are well fit by the new angular velocity, with north and east RMS misfits of only 0.8 and 0.9 mm/yr, respectively. India fixed velocities suggest an approximate of 1–2 mm/yr intra-plate deformation that might be concentrated along regional dislocations, faults in Peninsular India, Kachchh and Indo-Gangetic plain. Relative to our newly-defined India plate frame of reference, the newly estimated velocities for 43 other GPS sites along the plate margins give insights into active deformation along India’s seismically active northern and eastern boundaries.
Source: https://www.nature.com/articles/s41598-017-11697-w
More Articles...
- Parameterization of water vapor using high-resolution GPS data and empirical models
- Structural insights from geodetic Global Positioning System measurements in the Darjiling-Sikkim Himalaya
- Seismic hazard and risk assessment based on Unified Scaling Law for Earthquakes: thirteen principal urban agglomerations of India
- Monsoon rainfall over India in June and link with northwest tropical pacific
- Simulation of extreme temperature over Odisha during May 2015