Mild Tremors Jolt Citizens No Loss Of Life Or Property Recorded

Mumbai: Citizens felt mild tremors for a few seconds in the city on Saturday morning.      According to Met department officials, the tremors were a shock effect of the earthquakes in Gujarat and Maharashtra.      Officials recorded a tremor measuring 4.9 on the Richter scale at 10.58am on Saturday in Satara, which is 213 km from Mumbai. Around 25  houses in the Konkan region were damaged. An aftershock was felt at 11.47am in Kolhapur, sending slight tremors in Mumbai again.      Those residing in Ballard Pier, Byculla, Dadar, Kurla, Chembur, Vashi, Santa Cruz and interior areas of Andheri are said to have experienced aftershocks. "I was reading a newspaper at home when I felt my chair shake. My father sitting opposite me also felt the same. I realized that we had felt a tremor," said Byculla resident Khushi Sharma.      India Meteorological Department director (Mumbai) Bishwombhar Singh said, "Two tremors were recorded in western India on Saturday. The first one, measuring 4 on the Richter scale, occurred at Bhuj in Rann of Kutch, Gujarat, at 8.53am. The one in Maharashtra occurred at 10.58am and its epicentre was Satara. There is no imminent threat or danger to Mumbai".      No loss of life or property was reported in the city.  MUMBAI'S RISK FACTORS Over 16,000 dilapidated buildings  The city's population density of 20,038 persons per sq km in the island city and 20,925 in the suburbs poses a challenge  Implementation of quake-resistant building codes questionable, particularly in older buildings  QUAKE-PROOF STRUCTURES  They aim to be monoliths or single entities where floors, walls and roofs are bound through steel liner plates that provide a cross-bracing of sorts. This helps the building put up a united front to a quake We are safe, can be safer: Experts  Mumbai: Saturday's tremors put the spotlight on the city's vulnerability to such disasters. A stricter vigil of earthquake-resistant building codes is needed, said experts, adding that Mumbai's cessed structures, slum sprawl and high population density pose enormous challenges in the face of an earthquake.      Said geologist V Subramanyan, "The BMC should conduct a survey to see how many of Mumbai's buildings are seismically-safe and strengthen those found unsafe through retrofitting."      He also underlined the need for an "upper limit to be placed on high-rises" given that the city falls in the moderate-risk seismic zone.      Pointing out that there are 16,000 dilapidated structures identified by theBMC and over 50% of the population lives in slums, experts said that there is a huge gap in the city's earthquake-resistant housing stock.      "The city's high population and structural density pose a challenge to disaster management but we have prepared a standard operating procedure to deal with earthquake-induced building collapses and landslides," said M Narvekar, head of the BMC's disaster cell.      Experts said newer structures have built-in seismic safeguards which are required to be followed by redevelopment projects as well. "New buildings are on a par with global standards and are designed to handle seismic load," said architect Hafeez Contractor.      Subhash Patil of the Institution of Engineers said the 1997 Latur earthquake had served as a wake-up call to engineers and buildings in Mumbai are safe enough to withstand the earthquake effect.      Prof Deepankar Chaudhary of IIT-B sounds a word of caution. "We are not that well prepared. The norm is to follow the Indian standard code to build safe structures but the codes which relate to designing foundation of buildings, retaining walls, etc, haven't been updated since 1984. Dynamic soil properties within cities, another major factor in determining safety, are not spelt out in building codes."