Geology topics

Haider Hasan

Publications and source records attributed to Haider Hasan.

4 recordsLinked to original sources

USGS2021

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.

Karachi↗

USGS2018

Karachi tides during the 1945 Makran tsunami

This paper extends and detides a Karachi tide-gauge record as an observational basis for assessing Indian Ocean tsunami risk. The extended marigram encompasses the time of the great 1945 Makran earthquake of early November 28, local time, and of the ensuing tsunami, which continued into November 29. The marigram was published previously as a 9-h excerpt that begins 1 h after the earthquake. The full marigram presented here covers most of 17 days from November 15 to December 1. Gaps include a tsunami-induced outage that may help explain why the highest water level gauged is 1 m below the maximum water level reported nearby. The detiding method computes a reference tidal curve that disregards all observations from November 28 and 29. For those 2 days, the reference tide is guided by Admiralty tide tables and, secondarily, by high waters and low waters gauged before and after. As in previous estimates, the detided tsunami crests about 0.5 m above ambient tide, but now with the possibility that the gauge failed to record a higher wave. Anomalies described for the first time include an early one that likely resulted from a recognized problem with the Karachi tide station, but which might instead represent an earthquake precursor.

Karachi↗

USGS2018

A digital elevation model for simulating the 1945 Makran tsunami in Karachi Harbour

The digital elevation model documented here provides a tool for calibrating tsunami models to effects of the 1945 Makran tsunami that were observed in Karachi Harbour. The DEM bathymetry is derived from soundings made mainly during the first 8 years post-tsunami. While deficient in its portrayal of interior tidelands and upland topography, the DEM accurately represents the setting of a tide gauge that recorded the 1945 tsunami.

Karachi Harbour↗

USGS2014

Elders recall an earlier tsunami on Indian Ocean shores

Ten years on, the Indian Ocean tsunami of 26 December 2004 still looms large in efforts to reduce coastal risk. The disaster has spurred worldwide advances in tsunami detection and warning, tsunami-risk assessment, and tsunami awareness [Satake, 2014]. Nearly a lifetime has passed since the northwestern Indian Ocean last produced a devastating tsunami. Documentation of this tsunami, in November 1945, was hindered by international instability in the wake of the Second World War and, in British India, by the approach of independence and partition. The parent earthquake, of magnitude 8.1, was widely recorded, and the tsunami registered on tide gauges, but intelligence reports and newspaper articles say little about inundation limits while permitting a broad range of catalogued death tolls. What has been established about the 1945 tsunami falls short of what's needed today for ground-truthing inundation models, estimating risk to enlarged populations, and anchoring awareness campaigns in local facts. Recent efforts to reduce coastal risk around the Arabian Sea include a project in which eyewitnesses to the 1945 tsunami were found and interviewed (Fig. 1), and related archives were gathered. Results are being made available through UNESCO's Indian Ocean Tsunami Information Center in hopes of increasing scientific understanding and public awareness of the region's tsunami hazards.

Eos, Earth and Space Science News↗