Event #5218: Earthquake associated with tsunami that destroyed much of Alexander's fleet in India

Text #3773

About the third hour, the ocean, according to a regular alternation, began to flow in furiously, driving back the river. The river-at first, arrested; then, impressed with a new fore-rushed upward with more impetuosity than torrents descend a precipitous channel. The mass on board, unacquainted with the nature of the tide, saw only prodigies and symbols of the wrath of the gods. Ever and anon, the sea swelled; and, on plains recently dry, descended a diffused flood. The vessels lifted from their stations, and the whole fleet dispersed,- those who had debarked, in terror and astonishment at the calamity, ran from all quarters toward the ships. But tumultuous hurry is slow. These, with boat-hooks, are hauling up their gallies: these, while fixing their seats, prevent the oars from being paired: some, hastening to sail, without waiting for the complement of mariners, impel languid hulls, unmanageable, crippled in the wings of navigation: other transports could not hold those who inconsiderately pressed into them: deficient, or redundant, numbers equally obstructed the impatient. Here was clamoured, “Wait:” – here, “Row off.” Dissonant voices, circulating inconsistent orders, prevented the multitude from acting by their own observation, or from hearing the general command. Nor availed the pilots; whose directions were either undistinguished in the tumult, or disobeyed by terrified and promiscuous crews.

Vessels dash together; and oars are by turns snatched away, to impel other gallies. A spectator would not imagine a fleet carrying the same army, but hostile navies commencing a battle. Prows strike against sterns: on the invading vessels, other drive aft. The fury of altercation carried the mariners to blows.

Now the tide had inundated all the fields skirting the river, only tops of knolls extant like little islands: to these, from the evacuated ships, the majority swam in consternation.

The dispersed fleet was, partly, riding in deep water, where the land was depressed into dells; and, partly, resting on shoals, where the flood had covered elevated ground: - Suddenly breaks on the Macedonians a new alarm, more vivid than the former. The sea began to ebb; the deluge, with a violent drain, to retreat into the frith, disclosing tracts just before deeply buried. Unbuoyed, the ships pitched, some upon their prows, some upon their sides. The fields were strewed with baggage, arms, loose planks, and fragments of oars. The soldiers, neither daring to descent to the ground, nor reconciling themselves to stay in the transports, awaited what calamities could follow heavier than the present. They scarcely believed what they suffered, and witnessed – shipwrecks on dry land, the sea in a river. Not yet ended their unhappiness; for, ignorant that the speedy return of the tide would set their ships afloat, they predicted to themselves famine and death. Terrifying monsters, too, left by the waves were vagrantly gliding around.

Text #3774

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The timing of the 325 BC tsunamigenic earthquake and the location of Alexander’s fleet were critical. If the earthquake had occurred later in November of 325 BC, after the fleet had left Morontobara (Karachi), or when it was near Bagisara (present Ormara), the outcome could have been disastrous. The delay due to adverse monsoon winds probably saved Alexander’s fleet from total tsunami destruction. […]

Renewed southwest monsoons and dwindling food and water supplies slowed the fleet’s progress - forcing Nearchus to seek safe anchorage for the ships and to establish a fortified shore camp for about 24 days, while waiting for better weather conditions.

From Plutarch’s description and timing it can be safely concluded that the camp was established just south of the Hab river (south of present Karachi), designated “Port of Alexander”. Upon establishing this camp, the soldiers were forced to hunt and fish for food and to drink briny water.

The most likely location of the Greek fleet in late October /early November 325 BC when the fleet was struck by the tsunami generated by a large earthquake in the Makran Subduction Zone.

It was probably at this time and at this location - in late October / early November 325 BC - that the large earthquake and tsunami occurred near the Indus delta/Kutch region where the fleet had taken refuge. According to Lietzin (1974)¹, the earthquake had large magnitude and massive waves destroyed a good part of Alexander’s fleet. Also, according to Sri Lankan texts, a destructive tsunami struck the east side of the island. However, no details are available as to the exact date of the event, the location of Alexander’s fleet at that time, or the extent of the losses.

… the source area of the 325 BC tsunami along the Makran region had an east west orientation - similar to that of 1945. The azimuthal propagation of the tsunami energy was greater to the north and to the south. Since the Greek fleet was still in the Indus delta/Kutch region - to the east of the generating area near the mouth of Hab River - it is estimated that it was struck by waves that were about 2 meters in height. The wave heights of the 1945 tsunami were significantly lower to the east. In 1945, Karachi was struck by waves that were only 2 meters (6.5 feet) high. However, along the Makran coast, the 1945 waves reached a maximum run up height of 13 m (40 feet), destroyed fishing villages, caused great damage to port facilities and killed more than 4,000 people. We can conclude that the 325 BC tsunami had similar wave heights.

1. Lietzin E., Sea-Level Changes, 1974, p. 259-260 [nE] ↩