Around the end of June 2013 there was a mid-Atlantic earthquake. Almost immediately there was a great deal of concern being expressed on Facebook as to whether or not a tidal wave alert had been issued for these islands. And they had a right to be concerned. Tidal waves and earthquakes are married to each other and are part of our history.
I remember once in 1961 or so sitting on the beach side of Capt. Hodge Guesthouse watching him cleaning up the patio. Suddenly we heard a loud whistling noise followed by an earthquake. I had experienced a pretty severe earthquake on Saba in 1950 but the whistling noise was new to me. I could see that the Captain looked quite concerned in the direction of the sea. He said to me that the biggest concern for people on St. Martin should always be a tidal wave though on that occasion nothing further happened.
The Atlantic Ocean has the capacity to have the same kind of subduction earthquake as was caused in the subduction zone where the Indian Ocean “plate” is “subducting”, or sinking and pushing under the Asian plate. To do this, the tectonic plate boundaries must slide past each other on a regular basis. If ruptures, hence earthquakes, do not occur regularly and the plates “lock”, then when the rupture eventually occurs even more strain energy is there to be released, the earthquake is larger in magnitude (a 9.0 on December 26, 2004), and more physical rupture of the ocean floor occurs over a wider area (on December 26th over a 1,200 km length of the fault ruptured the ocean floor) and an even bigger tidal wave can be created. In the Atlantic there is a major subduction zone to the East of the Lesser Antilles as a segment of the Atlantic plate and is subducting westward under the Caribbean plate. Subduction earthquakes in that zone are certain over time, and tidal waves are a real possibility.
In a correspondence with Allan Ruffman of Halifax Nova Scotia in 2005 he had the following to say of the Lisbon earthquake of 1755: “We know from rather anecdotal and often-repeated, reports that the Lisbon tidal wave which had propagated all across the Atlantic at the speed of about 700km/hr, was seen in eight of the Lesser Antilles; Grenada, Martinique, Dominica, Guadeloupe, Barbados, Saba, St. Martin, Antigua, and perhaps in Southeast Cuba. In all cases, it arrived in the daylight hours of the mid-afternoon of Saturday, November 1, 1755 – All Saints Day. Via a November 26, 1756 lecture of John Winthrop II in Harvard Chapel, cited, indeed quoted, a recently-received letter from an unknown person, who was presumably on the island of St. Martin and who had witnessed the tidal wave on that island. He further stated: “An account which we have lately received from the West-Indies, This account is, that “on the 18th of November, about two o’clock in the afternoon, the sea withdrew from the harbor of St. Martin’s, leaving the vessels dry, and fish on the banks, where there used to be three to four fathoms of water; and continued out a considerable time; so that the people retired to the high land, fearing the consequence of its return; and when it came, it arose six feet higher than usual, so as to overflow the low lands.” there was no shock felt at the above time. There were those who questioned rightfully Winthrop’s date. Robert L. Rothman indicated that he had found two references that apparently contained information that indicated that the tidal wave arrived at 2.00 p.m. (1400 local time) on November 1st, 1755 on the island of St. Martin, not on November 18th, 1755. Mr. Ruffman in his letter to me further stated:” Not only did a Lisbon Earthquake cause a very serious tidal wave on November 1, 1755, but the same sort of a “subduction earthquake” as occurred off the Sumatra coast on December 26, 2004 can, and will, occur in the seduction zone (a deep ocean trench) that exists to the East of the Windward Islands of the Caribbean. It is this zone that eventually will cause a similar serious seismic event and a possible tidal wave in the Atlantic,and it would be prudent for the Caribbean to be ready for it. Suffice to say that, if you ever feel a strong earthquake on your island, think “tidal wave” and immediately go inland to high ground>20m in height, or go to the upper floors of a very strong concrete building (not wood, stone or brick).”
In 1655 the troops of Oliver Cromwell captured Jamaica from the Spaniards. The English then proceeded to build a small town named Port Royal on a spit of land jutting out from the mountains on the bay where now the City of Kingston lies.
But there were soon ominous signs that Port Royal held its own dangers. In addition to the tropical storms and hurricanes that swept over Jamaica, the English settlers reported that the ground beneath their new settlement shook regularly with tremors. The Spanish could have told them about another phenomenon that visited the coasts of the New World: the maremoto, or tsunami. The first recorded maremoto in the New World had smashed into the several towns along the shores of Venezuela, one wave surge so powerful that it demolished a naturally formed dike and severed the peninsula of Araya from the South American mainland, drowning many Indians in its wake. The Spanish heard stories of the monster wave when they conquered the area decades later. In 1530 they witnessed their own tidal wave, which struck various points along the South American coast. “The ocean rose like a miraculous thing to see,” said one report, while another spoke of a massive inflow of black, fetid salt water that smelled strongly of sulfur. The water surged twenty-four feet and destroyed a Spanish fort and may have drowned people as far away as Puerto Rico. Modern scientists could have told the English settlers that the Caribbean averaged some kind of tidal wave event once every twenty-one years. In a sense the clock on Port Royal was ticking from the moment the first cornerstone was laid.
In 1687 on February 19th, a minor earthquake struck Jamaica.”It was felt all over the island at the same time,” wrote Sloane. “Houses were near ruin with few escaping injury.” The tremors seemed to be getting more frequent. Just about a year later, Sloan reported three short shocks over the span of a minute, with the sounds of thunder that seemed to be coming from under the ground. In 1690 a quake rocked the Eastern Caribbean, with a huge chunk of rock formation on the island of Redonda splitting off and crashing into the ocean. Sugar mills were swallowed up on St. Kitts, and people died on Antigua. The Governor of the island of St. Thomas reported that the sea withdrew, and townspeople could walk out onto the seabed and collect fish flopping on the dry land. The end came for Port Royal on June 7th 1692 when the city was destroyed by an earthquake and then swallowed up by a tidal wave.
The Governor of Montserrat reported that on Christmas day, 1672 a terrible earthquake had leveled to the ground the two churches which after having been destroyed by the French had recently been rebuilt. The Governor further noted that “had the people been in the afternoon at church they would have been knocked in the head.” In some houses persons were killed, as in his own “it is beyond my purpose to express the miraculous escape of my own family and others.” On April 16th, 1732 a severe earthquake struck St. Martin. And there were many more through the centuries since Europeans settled these islands.
The Oxford Journal of August 11th, 1770 states the following: By letters from Amsterdam there are accounts of an earthquake having lately been felt at the island of St. Eustatia, in the West Indies, which considerably damaged the Dutch plantations.
A strong 7.5 magnitude earthquake followed by a tidal wave was felt at St. Croix on November 18th, 1867. This occurred in an intraplate fault of the Anegada Trough separating St. Croix from the main chain of the Virgin Islands. Louis van Housel, a United States naval officer serving on the vessel “Monongahela” under Commodore Bissel’s command wrote an interesting account entitled “An Earthquake Experience” which was originally published in Scribner’s Monthly in 1878. Very interesting reading and we will only quote a small part from the eyewitness account.
“Nothing unusual attracted our attention until three o’clock in the afternoon of the 18th of November, when our vessel began to quiver and rock as if a mighty giant had laid hold of her and was trying to loosen every timber in her frame. Officers and men ran pell-mell on deck to ascertain the cause of such a phenomenon. The vibrations continued the space of perhaps a minute, accompanied by a buzzing noise somewhat like the draught of a smelting furnace, or the hum of innumerable swarms of bees. So certain were we that the cause was connected in some way with the ship that no one cast an eye on shore. “It’s an earthquake, sir; look ashore!” shouted from the bow an old blue jacket, who had felt the peculiar sensation before. I looked toward Frederickstadt and saw a dusty atmosphere over the town. I could see men, women, and children, running hither and thither, and could catch faint cries of distress.”
Further on the account continues: “By this time the rush of waters was toward the ocean. We were carried out perhaps five hundred yards from the shore, when our vessel grounded and the water continuing its retreat, she careened over on her port beam’s ends. The bottom of the roadstead was now visible, nearly bare, for a distance of half a mile beyond us, and that immense body of water which had covered the bay and part of the town was re-forming with the whole Atlantic Ocean as an ally, for the tremendous charge upon us and the shore. This was the supreme moment of the catastrophe. As far as the eye could reach to the north and to the south was a high threatening wall of green water. It seemed to pause for a moment as if marshaling its strength, and then on it came in a majestic unbroken column, more awe-inspiring than an army with banners. The suspense was terrible! Our, noble vessel seemed as a tiny nutshell to withstand the shock of the mighty rushing Niagara that was advancing upon us. “Hold fast!” was the cry, as the tidal-wave struck the ship with gigantic force, making every timber shiver. Yet, singular enough, not a drop of water reached her decks. Being rather flat – bottomed the first effect of the blow was to send her over her starboard beam’s ends, which gave the water an opportunity of getting well under her before righting, when she was buoyed on the crest of the wave and carried broadside to the shore, finally landing on the edge of the street in a cradle of rocks that seemed prepared for her reception. Here she rested with her decks inclined at an angle of fifteen degrees. A small Spanish brig was carried bodily inland across the cane-fields and landed in the midst of the king’s highway.”
On December 31st, 1867 the Reverend Henry Warneford of the Anglican church on Anguilla who also served Saba wrote in his journal:” I spent the last Sunday in the year on Saba, on which occasion I had a full Assembly at both morning and evening services. Indeed I may say I had a Congregation all Sunday night, far into Monday Morning – for on that night at 9 we experienced a fearful shock of earthquake and in a few minutes the Governor’s house (Moses Leverock) was filled by a terrified crowd, for whom, after some order was restored, I prayed, and implored God’s merciful protection, and administered from time to time words of consolation to those ready to faint with fear, imploring them to put their trust in God. On Monday morning I proceeded to the Windwardside, and held service as usual in Capt. John Hassell’s hospitable house, to a large assembly of attentive and fear-stricken people (for the Mountains still quake).”
In his book “Memories of St. Martin N.P.” Mr. Josiah Charles Waymouth mentioned that 1867 was the year of another great tidal wave and earthquake. The sea receded an unusual distance and fishes were seen wriggling on its naked bed. According to reports of eye witnesses, given at the time, there was much consternation and some were preparing to escape to the country- then the disturbance ended with nothing more serious than the swashing of the surf up into “Miss Melia’s Alley” a cross-street later renamed Loodsteeg.”
I heard stories of this tidal wave from my grandmother and on Saba a large wave had come from the sea past where the school is now and down into the Cove Bay. Her parents had passed on information received from friends living on St. Martin about the reaction of the people there in 1867. Teacher Frank Hassell tells me that in 1950 when he lived by Miss Browlia Maillard on the Backstreet they made preparations to go to French Quarter after the earthquake, but it proved not to be necessary after all.
It would seem that earthquakes and tidal waves are in our genes and we should look for signs if living in a low lying area and if after an earthquake you see the sea receding then run as fast as possible to higher ground.