RESPONSE OF RIVER NETWORK AND MORPHOLOGY TO EARTHQUAKES IN OHIO

Low to moderate tectonic activities occur in several Ohio counties. Studies on the effects of Earthquakes on river network and morphology (e.g. gradient and sinuosity) were initiated in the mid 80's and revealed specific river responses that could indicate underground faults. This paper is about a study that consisted of: 1) Describing the river network in areas where fault systems are well identified in Ohio (e.g. Anna Seismogenic Zone) and where Earthquake causes still remain unexplained (e.g. Perry County); 2) Plotting longitudinal profiles of rivers in relation to their gradient and sinuosity for different tectonic zones; 3) Identifying zones of subsidence or uplift along river profiles; 4) Investigating field areas revealed in (3), recording fluvial landscapes and deposits (e.g., as seen in trench sections in exposed bars, using photographs or sediment samples). This paper presents preliminary results relating river characteristics to fault systems, then compares these results with those from areas where faults are not visible at the surface. Also, similarities and differences in river network, river sinuosity and gradient between locations that were or were not affected by the last Glaciation are shown.