Description: From Smithsonian Institution (1988): "Increased steam emission follows earthquake. At 1405 on 30 July, MarkAir pilots Kriss Paul and Bruce Gorham observed larger than normal steam emission from Augustine. When first observed, the plume was described as dirty steam with dark streaks at 1600 to 1800 m altitude, but it rose to about 2,700-3,000 m altitude within several minutes. At 1530, on their return from Kodiak to Anchorage, the pilots observed the plume spreading E and topping out slightly higher than 3600 m altitude. The volcano has emitted steam continuously since its 1986 eruption. Less than 4 minutes before the plume was first observed, an earthquake with an epicenter of 60.0°N, 153.5°W (about 75 km NW of the volcano) was felt in the lower Cook inlet region. The event occurred at 1401:29 and was located by the Alaska Tsunami Warning Center at a depth of 169 km with a local magnitude of 4.1. The University of Alaska Geophysical Institute seismic network detected two Augustine earthquakes at about 1603 and 1621 with above-normal magnitudes (about 1)."