Amazonian Terrors

Species Seeker extraordinaire Henry Walter Bates reported that Amazon boatmen “live in constant dread of the ‘terras cahidas’.”  What are they?

1.  Earthquakes.

2.  Giant crocodiles.

3.  Landslips.

4.  Floating logs.

And the answer is:

Landslips.

Canoemen, Bates wrote, “live in constant dread of the ‘terras cahidas,’ or landslips, which occasionally take place along the steep earthy banks, especially when the waters are rising.” He was inclined to dismiss the stories that “these avalanches of earth and trees” could swamp even larger vessels.  But one morning before dawn “an unusual sound resembling the roar of artillery” startled him out of his sleep.  It felt at first like an earthquake, “for, though the night was breathlessly calm, the broad river was much agitated and the vessel rolled heavily.”

The “thundering peal” of explosions rolled back and forth along the river, with “a long, continued dull rumbling” in the intervals.  When day broke, he looked to the opposite riverbank, three miles off, and saw that “Large masses of forest, including trees of colossal size, probably 200 feet in height, were rocking to and fro, and falling headlong one after the other into the water.”  The impact sent out a sort of Amazonian tsunami that undermined other parts of the bank, extending the landslip over a mile or two of coast.   “And thus the crashes continued, swaying to and fro, with little prospect of a termination” as their boat went out of sight up river two hours later.