Karachi effects of the Makran earthquake and tsunami of November 1945: Mercury spilled, tide gauge impaired, seawalls overrun, boats displaced, mosque flooded

An earthquake and tsunamiI on November 28, 1945, sourced near the Makran coast of the Arabian Sea, disturbed port facilities and fishing villages to the east at Karachi Harbour.

Seismic waves, some 300 kilometers from their Makran source, spilled mercury high in a lighthouse at Manora. One liter of the heavy, toxic liquid escaped from an annular trough in which one of the world’s heaviest assemblies of concentric glass prisms usually floated and revolved.

Ensuing tsunami waves registered incompletely at a tide gauge, also at Manora. Prior blockage of a stilling well may have held down the recorded level of the first few waves. The highest wave went ungauged by breaking a mechanical connection between water levels and a graphing pencil.

That highest wave overtopped seawalls of Keamari (Kiamari), according to newspaper accounts. The overflow reportedly flooded oil facilities, damaged 120 meters of Keamari Groyne, and destroyed a beacon on the groyne. By one account water apparently flowed from east to west in the bight south of Keamari.

Interviews seven decades later elicited memories of displaced boats. In Karachi, a scion of a shipping family recalled observing, a few days after the tsunami, a pair of military landing craft atop Keamari wharves beside which the craft had been berthed, he said, as ferries serving schools of the Royal Indian Navy. In Gujarat, a former sailor and port official told of feeling the tsunami suddenly lift an ocean-going dhow that had been grounded for hull cleaning near Baba Island.

Others interviewed testified to flooding in fishing villages on Baba and Bhit islands. Three independent accounts told of water entering a Bhit Island mosque.

Likely water levels at the overrun seawalls, stranded landing craft, and flooded mosque all exceed the maximum wave height gauged at Manora.

A tsunami like the one in 1945 would today encounter more people and developed property in Karachi’s port areas. The population of port villages has increased tenfold or more, as has the tonnage of imports and exports.