Soil gas CO2 emissions from active faults: a case study from the Anninghe—Zemuhe fault, Southeastern Tibetan Plateau, China

Introduction: Carbon dioxide emissions from non-volcanic areas are undervalued in the carbon cycle. Methods: First estimates of diffuse CO 2 flux Anninghe—Zemuhe fault (AZF), Southeastern Tibetan Plateau, China, which suggests this could equal 15% all volcanoes China. Following accumulation chamber method, was investigated at 1,483 points, and along 67 profiles crossing AZF. Results discussion: Total AZF were estimated 1.2 Mt yr -1 . The relationship between soil gas fluxes, earthquakes, activity discussed. intense southern part Zemuhe (ZMHF) northern Anninghe (ANH) inferred, have enhanced porosity soil, accelerated water-rock interactions emission within zone. chemical isotopic data indicated that biogenic primary source Produced by groundwaters carbonates, migrate to near surface through cracks. Spatial variations indicate seismic be responsible for jumpy flux. deep faults may contribute considerably greenhouse cycles.