After a
foreshock between 19:00 and 20:00 local time, the main earthquake struck at around 22:00, and numerous
aftershocks followed through that night.
Basel experienced a second, very violent shock in the middle of the night. The town within the ramparts was destroyed by a fire when torches and candles falling to the floor set the wooden houses ablaze. The number of deaths within the town of Basel is estimated at 300. All major churches and castles within a radius of Basel were destroyed. On the other hand, recent
paleoseismic studies attribute the cause of this earthquake to a
normal fault, oriented NNE-SSW and south of the town. The significant magnitude of the event suggests a possible extension of this fault under the town.
Location Due to the limited records of the event, a variety of
epicenters have been proposed for the earthquake. Some of the proposed locations include
faults beneath the
Jura Mountains or along the Basel-Reinach
escarpment.
Intensity The earthquake was felt as far away as
Zurich,
Konstanz, and even in
Île-de-France. The maximum intensity registered on the
Medvedev–Sponheuer–Karnik scale was IX–X (
Destructive–Devastating). The macroseismic map was established on the basis of damage reported by the region's 30 to 40 castles. From this macroseismic data, various studies have been conducted to estimate the
moment magnitude of the earthquake, which have resulted in various values of 6.2 (BRGM 1998); ==See also==