Florida

Earthquake History of Florida: 1727 to 1981

Charles J. Mott
Division of Science and Mathematics,
St. Petersburg Junior College,
Clearwater, Florida 33515

Abstract: Published accounts of seismic events reported in Florida are reported from the time of occupation of the Florida Peninsula to December 1981. Events are cited by date, time and geographic locality. Note is taken that a continuously recording seismograph has been operational since October 1977.

While the seismic events reported from the Florida peninsula and panhandle have indeed been rare, earthquakes have occurred and been felt. Thirty-three are identified herein. Spanning over 250 yr. reports have come from Pensacola to Key West. Shocks varied from slight shudders to violent shakings that destroyed buildings.

Few records of seismic shock have corroborative seismic evidence in the form of seismogram data. Many of the shocks reported or recorded in Florida seem to be related to seismic events elsewhere in North America.

Earliest seismic reported were plotted on the 10-point Rossi-Forel Scale. This scale measured earthquake intensity and was based on a subjective set of criteria. The more recent Modified Mercalli Scale is a 12-point scale that is slightly more objective. Earthquake ratings on this scale are written as upper case Ms followed by the Roman numeral designating the intensity of the tremor. For example, MMIV would represent an intensity 4 shock on the Modified Mercalli Scale. Rossi-Forel estimates have been converted to Modified Mercalli intensity equivalents in this paper.

1727 October 12. "Severe" tremors were reported and mentioned by Campbell (1943) and Lane (1976). However, the original record of these quakes has been lost. A severe shock was reported in New England on this date at 10:40. Reports of another shock came from Martinique on the same day. The relationship of either of these to the St. Augustine tremor was not established.

1780 February 6. A mild tremor was reported from Pensacola on this date (Lane, 1976). No damage was reported.

1781 May 8. A severe earthquake was reported at a military installation near Pensacola. While no fatalities were reported, shocks tore ammunition racks from barracks walls and leveled a house in the area (Lane, 1976).

1842 May 7. This tremor was felt from Florida to Louisiana. It may have been associated with a severe earthquake that struck Santo Domingo at about the same time. Sources report the disappearance of some Florida lakes on the day of this earthquake (Niles National Register, 1842).

1843 February 8. An earthquake was reported from the rural areas of the State. This tremor might have been associated with a tremor on the West Indies which occurred at the same time (Lane, 1976).

1879 January 12. Two severe shocks of about 30 sec each occurred from an area from Ft. Myers to Daytona and from Tallahassee to Jacksonville, and from all areas in between. The epicenter was located at 29°30'N, 82°00'W (U.S. Coast and Geodetic Survey, 1938). The shock was reported by hundreds of residents over a 25,000 square mile area of the Florida peninsula, and ranged from MMVIII to MMIX.

At St. Augustine, articles were thrown from shelves. In other locations, windows rattled violently and walls cracked. Rockwood (1880) indicated that the tremor progressed from the NW toward the SE between Gulf Hammock and Okahumpa. In the Tampa Bay area, Campbell (1943) states that the shock seemed to move from the SW to NE and was preceded by a rumbling sound ". . . as of a distant railroad train." MMVI was reported near Gainesville (Lane, 1976).

1880 January 22-23. On this date, a violent series of earth tremors struck at Cristobal, Cuba. At about the same time, 5 shocks were felt in Key West. Additional, more gentle shocks were felt in Key West through 26 January (U.S. Coast and Geodetic Survey, 1938).

1886 January 8 (a). Reid (1886) reported a shock in Jacksonville with no damage or injuries.

1886 August 31 (b). There were a series of strong shocks in Charleston, South Carolina on this date. The tremors in Charleston began at 21:51. In Tampa, residents reported 2 shocks, the first at 21:51, the second at 22:00. The first appeared to move NE to SW, while the second seemed to travel SW to NE.

In St. Augustine, church bells tolled as the tremor passed, while near Tallahassee, the water in Lake Jackson disappeared. A well near Graceville began to flow (Campbell, 1943).

1886 September 1-9 (c). Many reports of shocks were from throughout the area, with most coming from Jacksonville. These tremors were probably associated with aftershocks from the Charleston, South Carolina earthquake (Reid, 1886).

1886 September 22 (d). A 3-sec shock was felt in Archer, Florida. No damage, no injuries (Reid, 1886).

1886 September 29 (e). Slight shock reported. No injuries, no damage (Reid, 1886).

1886 October 22 (f). A single tremor passed through Jacksonville causing windows and dishes to rattle. On this date, similar shocks were felt in Charleston, South Carolina, as well as in Atlanta and Augusta, Georgia (Campbell, 1943).

1893 June 20. A shock of at least 10 sec duration was felt in Jacksonville, MMIV (Reid, 1907).

1900 October 10 (Stover et al., 1979). Reid (1907) estimates the epicenter of this tremor to have been at 30°20'N, 81°40'W. It was felt at Jacksonville at 11:15 and afterward. Eight distinct shocks were reported without damage and injuries. The intensity of this tremor was MMV. A tremor was also felt in Lake City about this time.

1902 May 20-21. Residents reported hearing a noise like heavy cannon fire at a distance. The noises preceded the actual tremor by about 3 min. Tremors were slight and without damage (Reid, 1907).

1903 January 23. A shock wave of MMVI was felt in north Florida and in Savannah, Georgia. No damage (Lane, 1976).

1905 September 4. MMIII shock was accompanied by slight rumbling noises. Duration was 10 sec without damage (Reid, 1907).

1924 October 20. A tremor of intensity MMIV shook the area. Windows and doors rattled, but there was no damage (U.S. Coast and Geodetic Survey, 1924). An earthquake was felt throughout Virginia, Tennessee and South Carolina at about the same time (Bollinger, 1977).

1930 July 19. Widespread shocks were felt over a wide area of west-central Florida. The shocks were so evenly spaced that blasting, at first, was thought to be the source of the shocks. However, Campbell (1943) points out that the size of charge necessary for a shock to be felt over such a large area would be highly unusual. Furthermore, no blasting of any sort was scheduled or recorded on that day. He suspects a seismic origin for the shocks.

1935 November 13. Two short tremors were felt. The second tremor lasted 15 sec. In Palatka, shocks were abrupt and forceful enough to cause people to run from their homes and into the streets. No damage or injuries were reported (Seismological Society Bulletin, 1936).

1940 December 26. A slight shock was felt in the Tampa Bay area. Campbell (1943) reports that a seismic origin for this shock is in doubt, but gives no details. However, the U.S. Coast and Geodetic Survey (1940) does list a tremor on this date and time.

1942 January 19. Five to 7 evenly spaced tremors were felt from Miami throughout the Everglades. Each shock lasted about 1 min, and the shocks were spaced at 3 min intervals (Campbell, 1943). In Hollywood, whole houses shook. Moorehaven, on the south shore of Lake Okeechobee, reported 12 tremors. Still farther west, Alva reported 20 shocks, ranging from MMV to MMVII (U.S. Coast and Geodetic Survey, 1942).

1945 December 22. Press reports state that alarmed citizens felt a seismic shock in the area. A seismograph at Spring Hill College, near Mobile, Alabama recorded a slight earthquake on this date and time (U.S. Coast and Geodetic Survey, 1946).

1948 November 8. A sudden jar caused doors and windows to rattle. Residents report an accompanying sound like distant heavy explosion. Recorded as MMV (U.S. Coast and Geodetic Survey, 1948).

1952 November 18. This was a MMIV tremor felt in Lake City and in Quincy. A policeman in Quincy is said to have noted the exact time of the passing tremor on the back of a parking citation which he was issuing at the time (U.S. Coast and Geodetic Survey, 1952).

1953 March 29 (Stover et al., 1979). Slight tremor felt in Orlando.

1964 March 2. No surface expression of a tremor, but significant oscillations were noted in water well data collected by the United States Geological Survey. These oscillations were possibly associated with the Good Friday Alaska earthquake which happened in this date (Stencil, 1976).

1973 October 27 (a). Slight tremor reported in a broad area of central Florida (Stover et all., 1979).

1973 December 5 (b). Tremor reported at 11:30, Seminole and Orange counties.

1975 December 4. A MMIII to MMIV tremor was detected by most residents within a 10-mi radius of Daytona Beach (Stover et al., 1979).

1977 November 27. In October, 1977 the Earthquake Seismograph Station at the University of Florida became operational (Smith, 1978). No local events were recorded until November, 1977 when slight shock was recorded north over peninsular Florida. This tremor was not large enough to be felt, but was recorded as Richter magnitude .8.

At this writing (December, 1981) no additional tremors have been recorded. However, with the advent of continuous seismic recording for Florida, continuous updating of this record may now be accomplished. (Smith, Dec. 1981, pers. comm.)

Literature Cited

Bollinger, G.A., and M.G. Hopper. 1972. The Earthquake History of Virginia: Virginia Polytechnic Institute, Blacksburg, Virginia.

Campbell, R. 1943. Earthquakes in Florida: Proc. of the Florida Acad. of Sci. 6:3-4.

Lane, E. 1976. Earthquakes in Florida: Florida Conservation News. 11:6.

Lovering, F.W. 1935. Reported in Paradise. F.W. Lovering, Publ., Medford, Massachusetts.

Moneymaker, B.C. 1967. Personal communications and file of seismic events of the Southeastern United States.

Niles National Register. 1842. June 26. page 272.

Reid, H.F. 1907. Monthly Weather Review: American Meteorology Soc. 35:572.

Reid, H.F. 1907. Monthly Weather Review: American Meteorology Soc. 14: September, page unknown.

Rockwood, C.G. 1880. Notice number 9: American J. of Sci. 19:296-299.

Seismological Society Bulletin. 1936. Seismological Society of America. 26:92.

Smith, D.L. 1976. Florida Scientist (Supplement): 42nd Annual Meetiing of the Florida Acad. of Sci. 46:35.

Smith, D.L. 1981. Personal Communication, December 4, 1981.

Stencil, S. 1976. Earthquake Forecasting: Editorial Research Rept. 11:3.

Stover, C.W., B.G. Reagor, and S.T. Algermissen. 1979. Seismicity map of Florida: United States Geol. Sur. Map Number MF-1056 (Florida). United States Geol. Sur., Reston, Virginia.

U.S. Earthquakes, Coast and Geodetic Survey: 1952, Serial Number 773, page 7; 1948. Serial Number 746, page 6; 1945, Serial Number 699, page 6; 1942, Serial number 662, [age 4; 1940, Serial number 647, page 14; 1938, Serial number 609, pages 24 and 30; 1935, Serial Number 600, page 15; 1930, Serial number 539, page 5; 1925, Serial Number 388, pages 72 to 74.

Abridged from Earthquake History of Florida: 1727 TO 1981, Florida Scientist, Volume 46, Spring, 1983, No. 2: 116-120.