India Places Entire Himalayan Arc in Newly Created Highest-Risk Zone VI on Revised Seismic Map

Key facts

• India has released a major update to its national seismic zonation map under the revised Earthquake Design Code.
• The Bureau of Indian Standards (BIS) released the revised map based on probabilistic seismic hazard assessment (PSHA) methods incorporating data on active faults, maximum potential magnitudes, ground-shaking behaviour, tectonic regimes and underlying lithology.
• 61% of the country now falls under moderate to high hazard zones.
• The entire Himalayan arc is placed in a newly created highest-risk Zone VI.
• The updated design code requires secure anchoring of non-structural elements such as parapets, ceilings, tanks, façades and suspended fixtures if they account for more than 1% of a building’s weight.
• Buildings near active faults must be designed to withstand severe pulse-like ground motions.
• The code adds new norms covering liquefaction, soil flexibility and site-specific ground-response spectra.
• Critical infrastructure including hospitals, schools, bridges, pipelines and major public buildings must remain functional after major earthquakes.