A vocabulary of landscape — a landscape of words
1083 entries
brontide
A low natural boom or rumble like distant thunder, heard under a clear sky with no storm and no detectable earthquake. Brontides come singly or in runs, they rattle windows, and they are reported most often near coasts and large lakes. Proposed causes range from waves interacting with the shape of a shoreline, to gas escaping from sediments, to very shallow seismic movement, to distant sound bent back down by a temperature inversion. None of them accounts for all of the reports.
Etymology
From Greek brontē, thunder — the same root as Brontosaurus, thunder lizard, and as Brontes, one of the Cyclopes in Hesiod, whose name meant thunderer. The ending is -ide in its Greek patronymic sense, offspring of, the ending English also uses for meteor showers: a Perseid is a child of Perseus, and a brontide is a child of thunder.
Notes
Every coast that gets them has named them. They are mistpoeffers, fog guns, in Belgium and the Netherlands; seeschießen, sea gunshots, in Germany; brontidi along the Italian coast, where the lore ties them to good fishing; the Barisal guns in the Bay of Bengal; the Seneca guns around the Finger Lakes and on the Carolina coast; and the Moodus noises in the lower Connecticut valley.