Report on causes and mechanism of Moeen Abad earth fissure

Description

Report on causes and mechanism of Moeen Abad earth fissure ABSTRACT:     Following of a formal invitation, from Disaster relief committee of Tehran province to evaluate potential hazard, in relation to forming a fissure in pishva region. A team from geological survey of Iran, Engineering Geology group, visited the area.      The main fissure in the area according to local people has been shaped during the past 8 years and in last year it developed in a faster rate. It is located between two point of near Moein Abad village. It shows a curvature nature with general direction of N27W, total length of 2.4 km, maximum width of 5 m (due to erosion process) and a maximum depth of 1.7 to 2m.      The main cause of forming this fissure, in a primary study, recognized to be a combination of variation in water level decline in that specific location and variable alluvial deposit (silty to clayey), that may have an affect on water movement in the area, apart from different compaction properties.    In the same times due to complexity caused by existence of Quaternary Pishva fault in the area further studies has been suggested. Also due to local structural geology some irregularities in bed rocks such as bed rock hills or fault scarp may be influence the forming this fissure, in this regard regular monitoring of forming the fissures in area, geoelectrical and gravimetry studies of existence fissures may be a help to more detailed understudying of the process.