DEPARTMENT OF THE INTERIOR UNITED STATES GEOLOGICAL SURVEY GEOEGE OTIS SMITH, DIBECTOB BULLETIN 494 THE NEW MADRID EARTHQUAKE BY MYRON L. FULLER WASHINGTON GOVERNMENT PRINTING OFFICE 1912 CONTENTS. Page. Introduction.............................................................. 7 General statement...................................................... 7 Field work and acknowledgments...................................... 7 The story of the earthquake................................................. 9 Sources of information.................................................. 9 Summary of the disaster............................................... 10 Previous earthquakes in the Mississippi Valley.............................. 11 Recorded shocks....................................................... 11 Indian traditions...................................................... 12 Geologic evidence..................................................... 12 Record of the shocks....................................................... 13 Atmospheric conditions preceding first shock............................ 13 Time of the shocks..................................................... 13 Center of disturbance................................................... 14 Earlier shock...................................................... 14 Subsequent shocks................................................. 15 Area affected.......................................................... 16 General destructiveness of the shocks.................................... 17 Number and distribution of the shocks.................................. 17 Effects of the shocks outside of the New Madrid area..................... 21 Mississippi Valley.................................................. 21 Ohio Valley........................................................ 22 Louisville..................................................... 22 Cincinnati..................................................... 26 Other localities................................................. 27 Great Lakes region................................................. 28 Atlantic Coastal and Piedmont plains................................ 29 Nature of the vibrations............................................... 31 Classification of intensities............................................. 33 Periods of activity....................................................... 33 Relation of distribution of shocks to time of day.......................... 35 Relation of distribution of shocks to diurnal variations of barometric pres­ sure. ................................................................ 36 Relation of distribution of shocks to phases of moon...................... 37 Relation of the earthquake and the weather............................. 39 Direction of vibrations................................................. 40 Effect of the earthquake on life......................................... 40 Government relief...................................................... 43 Phenomena of the earthquake............................................... 44 Atmospheric phenomena................................................. 44 Darkness......................................................... 44 Odors and vapors.................................................... 45 "Light flashes" and "glows"....................................... 46 3 4 CONTENTS. Phenomena of the earthquake Continued. Page. Geologic phenomena..........................:......... ..,............. 47 Fissures.......................................................... 47 Record of assuring............................................. 47 Character of the fissures........................................ 48 Types.................................................... 48 Form...................................................... 48 Arrangement.............................................. 49 Intervals................................................. 49 Direction.................................................. 49 Length................................................... 51 Depth.................................................... 51 Fillings (sand dikes)....................................... 51 Objects swallowed by fissures.............................. 52 Distribution of the fissures..................................... 52 Situation.................................................. 52 Localities.................................................. 53 Cause of fissuring............................................... 56 Bluff fissures............................................'... 56 Fissures of the sand-blow regions............................ 57 Fissures of the sand sloughs....................... ........ 57 Compound fissures........................................ 57 Faults............................................................ 58 Location....................................................... 58 Cause......................................................... 59 Landslides......................................................... 59 Chickasaw Bluffs............................................... 59 Location and character.................................... 59 Cause..................................................... 61 Warping.......................................................... 62 Uplifts and doming............................................ 62 The records............................................... 62 Tiptonville dome......................................... 63 Blytheville dome.......................................... 63 Little River dome.......................................... 64 Other domes............................................... 64 Cause of uplifts and doming................................. 64 Depression "sunk lands"...................................... 64 Types.................................................... 65 Form and trend............................................ 66 Amount of subsidence..................................... 67 Distribution.............................................. 68 Cause of sinking........................................... 74 Extrusion............................................................ 76 Records.......................................................... 76 Character of ejected material....................................... 76 Temperature of ejected water...................................... 77 Escape of gas and water after the earthquake........................ 78 Resulting features................................................. 79 Sand blows.................................................... 79 Nature................................................... 79 Situation............'...................................... 80 Distribution.............................................. 80 CONTENTS. 5 Phenomena of the earthquake Continued. Extrusion Continued. Resulting features Continued. Page. Sand sloughs.................................................... 83 Nature................................................... 83 Situation.................................................. 83 Distribution.............................................. 84 Sand scatters................................................. 85 Cause of extrusion.................................................. 85 Undermining......................................................... 87 Fault trenches..................................................... 87 Sand sloughs....................................................... 87 Sinks............................................................. 87 Hydrologic phenomena................................................ 89 Agitation of water surfaces......................................... 89 Effect on navigation................................................ 92 Caving of banks............................................... 92 Disappearance of islands....................................... 93 Snags and sawyers. ........................-..-.. --- ----- - - 94 Floating wreckage............................................. 94 Changes in springs.................................................. 95 Action of the earthquake on forests..................................... 95 Splitting of trees................................................... 95 Destruction of forests by waves and caving banks..................... 96 Overthrow of forests by landslides.................................. 96 General prostration of forests by vibrations........................... 97 Dead trees.............................................. ......... 98 Uplifted trees..................................................... 98 Submerged forests................................................. 98 Area of destruction................................................. 98 Effect on artificial structures............................................ 99 New Madrid region................................................. 99 Distant localities......................:............................ 100 Other physical phenomena............................................. 1.01 Noises................................. 1.......................... 101 Origin and cause of the New Madrid earthquakes............................. 102 Popular beliefs......................................................... 102 Evidence of origin...................................................... 103 Location of centrum................................................... 104 Ultimate cause......................................................... 105 Significance