Earthquakes have long been frequent in the area. The New Madrid Fault Zone (pronounced ) is named for the city of New Madrid in the Bootheel. This fault zone is entirely hidden beneath the deep alluvial deposits of the Mississippi embayment. Unlike the San Andreas Fault in California, it is not visible anywhere. This fault zone was responsible for an extremely powerful series of earthquakes that rocked the area in 1811 and 1812, known collectively as the New Madrid earthquake. It was reported to have been so powerful as to ring church bells along the East Coast. Subsidence formed Reelfoot Lake on the other side of the Mississippi River in West Tennessee. An eyewitness of the earthquakes of 1811 and 1812 noted: