Chapter 5 MONITORING TECHNIQUES OF MUD VOLCANISM MUD VOLCANOES OF PAKISTAN - AN OVERVIEWon three centuries of historic and recent investigations in Pakistan

The earliest reports on mud volcanoes in Pakistan stem from the year 1840. Despite recurrent visits ever since, progress in studying these features in detail has been slow. Increased interest in mud volcanoes occurred in the aftermath of an earthquake in 1945, which initiated the sudden emergence of islands offshore from the Makran Desert. These islands were built from highly viscous mud with a high gas content. The mud was driven up by high buoyancy forces. The study of mud volcanoes in Pakistan intensified concurrently with marine cruises offshore from the Pakistani coast, particularly during the last 15 years, by which mud volcanoes on the abyssal plain and widespread gas seeps in the shallow waters of the upper continental slope were identified. The discharged gases on and offshore are predominantly of bacterial origin and appear to rise from the upper km of the subsurface. Little is known about the periodicity of gas discharge. A new instrumentation to monitor gas flow periodicities is briefly described.