In the nineteenth century, Bermuda was of interest to a new breed of scientists, being geologists who studied the formation of the Earth.

One of their subjects related to the making of islands and Bermuda was somewhat of an anomaly, as it was not a typical coral atoll and was the northernmost of such phenomena worldwide.

A phenomenon (‘something that can be observed and studied and that typically is unusual or difficult to understand or explain fully’) that attracted the interest of such scholars visiting Bermuda at that period was the ‘travelling sands’ or ‘sand glaciers’ of the south shore, especially in the area of Elbow Beach and the strands along the south side of Tucker’s Town.

Of late, a wonderful pre-photography image of the mid-1830s by Dr Johnson Savage MD (reproduced here) has given us a vivid impression of one area of such dunes, thought to be at the eastern end of Elbow Beach.

In that view, the shifting sands have leapt over a boundary wall and are in the process of devouring a cedar forest; in the distance may be seen Cooper’s Island and Gurnett Rock.

Other sand glaciers were recorded by photography, when HMS Challenger visited Bermuda in 1873, on a global scientific voyage later documented in a report which was thought to proclaim “the greatest advance in the knowledge of our planet since the celebrated discovers of the fifteenth and sixteenth centuries”.

Likely in Paget Parish, the photographs illustrated the burying of a cultivated field by the ‘glacier’ and the almost complete burial of a house, which some may recall seeing in their childhood at the rear of Elbow Beach.

Now somewhat quiescent, the travelling sands were very active at times during the 1800s, and Bishop Inglis from Halifax observed the following on Monday, 25 May 1835 (from a transcription kindly made by Mrs ACH Hallett and digitised by James Hallett):

“Dr Hunter took us in his boat, under a comfortable awning, first to Castle Island, between three and four miles, where we landed and went through the ruins of this ancient defence of Bermuda. The scenery is all beautiful. We next rowed along the shore to Tucker’s Town, which legend says was once considerable, but now lies buried under sand. All this may be doubted. Formerly there were more houses than at present exist in the neighbourhood, and many persons were injured by the accumulation of sand to the depth of six, eight, and even ten and 12 feet in some place, and probably this discouraged occupation in the neighbourhood.’

“We saw a man about 50 years of age, who was so reduced by the accumulation of sand that he has never recovered from the injury. He showed us the ruins of the house in which he was born, and which his father was compelled to abandon. It is now covered to the depth of eight feet, but the lines of the walls, and the chimney, are still visible.

“He showed us a spot close to the house, which has fifteen feet of sand upon it, all accumulated within his recollection. But for the last ten years, there has been no increase, but rather the reverse, and the sand, which was formerly bare, and moving, is now fixed, and covered with herbage.”

By happy coincidence with the Savage watercolour, the Bishop lets us know that that evening, “we had a party at Mr. Lough’s for dinner, among whom was Dr Savage of the Artillery, a graduate of Trinity, Dublin, and a very accomplished person; he draws beautifully, and is an excellent musician”.

Bermudian hydrogeologist, Mark Rowe, has kindly commented on the travelling sands: “Notwithstanding their current state of relative stability, Bermuda’s coastal dunes exhibited pulses of mobility in the 19th century at several locations along the south shore. An example of such activity at Elbow Beach is depicted in Johnson Savage’s ‘Sand Hills’ watercolour dating from 1833 to 1836.

“Reports, from about the same time, describe the burial of several houses by dunes at Tucker’s Town and of at least one house near Elbow Beach.

“At the latter location, dunes, which climbed to a height of 180 feet and advanced at rates of ten to 20 feet per year, as documented by Lieut Richard Nelson in 1837, were still active when visited, as an object of scientific curiosity, by British scientists of the Challenger Expedition in 1873.

“Later still, geologist Angelo Heilprin (1887) observed dunes at Elbow Beach and Tucker’s Town which he described as ‘great tongues of sand’ and ‘sand glaciers’ … stealthily encroaching on hilltops of the interior and burying everything’.

“These observations of ‘modern’, albeit relatively minor, dune activity provide a valuable insight into the formation of the Bermuda Islands, which are for the most part constituted of lithified (hardened) sand dunes.

“In fact, the geological term ‘eolianite’, meaning a rock created by the cementation of eolian (windblown) sands, was coined in Bermuda in 1931 by geologist Robert Sayles.”

Mr Rowe wrote further that “The prevailing hypothesis that Bermuda’s ancient dunes accumulated over short periods, perhaps in storms, and were rapidly stabilised on the beach backshore is challenged by recent detailed geological studies of the eolianites”.

“It can now be shown that Bermuda dunes advanced inland at a steady pace over periods spanning many decades, or centuries, during which they continued to remain mobile.

“Geological evidence that they advanced considerable distances onto interior forested terrain is provided by preserved imprints of buried trees and by the geometry of the dune strata.

“Such proclivity for landward encroachment by Bermuda’s dunes is corroborated by the 19th century photographs, paintings and descriptions of historic activity, of which little evidence remains today.”

Not speaking politically, the shifting sands of our island home are fundamental to its existence.

The highly mobile, or ‘transgressive’ nature of Bermuda’s sand dunes, along with the causes of episodic activity and other aspects of Bermuda’s geology thought to be related to sea level change, are the subject of a series of geological articles by Mark Rowe, in collaboration with geologists based at London, Oxford and Edinburgh universities, expected to be published later this year.

Again not speaking politically, perhaps then we will have a better understanding of our shifting house of sand from the rock-solid scientific discipline of geology.

Edward Cecil Harris, MBE, JP, PHD, FSA is Director of the National Museum at Dockyard. Comments may be made to director@bmm.bm or 704-5480.