EARTHQUAKE RISK MANAGEMENT A.ABOUT EARTHQUAKES B. BUILDING RESPONSE C. DESIGN PRINICIPLES D. CONSTRUTION TECHNOLOGY E. EPILOGUE A:ABOUT EARTHQUAKES GENESIS Earth has four main layers 1. CRUST: 5-10 Km thk. bellow sea – Basalt type & 35 -70 Km thk. bellow land mass – Granite type It is thinner than apple skin. There are cracks in the crust dividing it in to 7 Major & 13 minor plates covering globe. MANTLE: 2900 Km thick, a mixture of molten & plastic rocks – Magma having Convectional Currents triggering volcanic action and imparting movement in Crustal plates. 3. OUTER CORE: 2200 km thk. having liquid metal. 4. INNER CORE: 2900 km across having solid Metal, mainly iron. Chains of volcanic ridges encircle the earth beneath its oceans. Magma in ridges exudes through cracks in the old sea bed. It then cools & hardens in to new crust. Earth’s ever widenin...