After the earthquake of Belluno (June 29, 1873), the torrent Tesa, which is ordinarily limpid, became very muddy.[55] Similar phenomena have been observed even in Britain, as, for instance, in 1787, when, at the time of a shock which was felt in Glasgow, there was a temporary stoppage in the waters of the Clyde. Again, in 1110, there was a dreadful earthquake at Shrewsbury and Nottingham, and the Trent became so low at Nottingham that people walked over it.
The earthquake of 1158, which was felt in many parts of England, was accompanied by the drying up of the Thames, which was so low that it could be crossed on foot even at London.[56]
Facts analogous to these are mentioned in the accounts of many large earthquakes. Sometimes rivers only come muddy or change their colour. In an account of the Lisbon earthquake we read that some of the rivers near Neufchâtel suddenly became muddy.[57]
At other times large waves are formed. Thus the earthquake of Kansas (April 24, 1867) apparently created a disturbance in the rivers at Manhattan, which rolled in a heavy wave from the north to the south bank.[58]
Sometimes curious phenomena have happened with regard to rivers without the occurrence of earthquakes. Thus, for instance, on November 27, 1838, there was a simultaneous stoppage of the Teviot, Clyde, and Nith.
In these rivers similar phenomena have been observed in previous years.
Again, on January 1, 1755, there was a sudden sinking of the river Frooyd, near Pontypool. This appears to have been due to the water sinking into chasms which were suddenly opened.[59]
Effects produced in springs, wells, fumaroles, &c.—Springs also are often affected by earthquakes. Sometimes the character of their waters change; those which were pure become muddy, whilst those which were hot have their temperature altered.
Sometimes springs have been dried up, whilst at other times new springs have been formed.
This latter was the case in New England (October 27, 1727). In some places springs were formed, whilst at other places they were either entirely or partly dried up.[60]