Volcano-Tectonic (Vt) Earthquake
Volcano-Tectonic (Vt) Earthquake : Often used to refer to ordinary (high-frequency or brittlefailure earthquakes) in a volcanic environment. This usage reflects an ambiguity whether the stresses leading to the earthquake are a result of regional tectonic processes or local magmatic processes, such as dike intrusion, or some combination thereof. See A-type earthquake