Study On The Physical Volcanology And Hazards Of Jinlongdingzi Volcano In Longgang Volcanic Cluster, Jilin Province

Jinlongdingzi volcano is located in Longgang volcanic cluster. As a relative young volcano, it has experienced many volcanic actions over a long period of time. The chronology of its eruptions can be divided into several phrases including the early Jinlongdingzi explosion phrase, late Jinlongdingzi explosion phrase, late Jinlongdingzi strombolian phrase and five lava flow units. Jinlongdingzi composite cone, broad tephra fall deposit and westward lava flows were formed after these volcanisms. By doing detail field investigation and indoor analysis, we finally reconstruct the primary physical characters: the total volumes are 0.33km³, 0.06km³ the total mass are 3.5×10¹¹kg, 7.8×10¹⁰kg of the fall deposits, height of the volcano columns are 14.31km , 6.60km, volume discharge rates are 4.0×10³m³/s, 0.2×10³m³/s, mass discharge rates are 4.2×10⁶kg/s, 2.6×10⁶kg/s, the duration time are 22.92h, 83.33h, the explosive magnitude are 4.5, 3.9, intensity are 9.6, 8.4, the erupted thermal power are 5.2×10¹⁷J, 1.2×10¹⁷J. The effusive physical characters such as the mean magma effusive rate, the speed of the lava flows, the durable time of the effusion etc are also reconstructed and the relative importance of the factors controlling the lava flow lengths of this area is lava flow volume>average eruptive rate>lava viscosity>average gradient of the surface. The reconstructed physical process of this volcano will help people in making future volcanic hazards mitigation plans.