October 6, 1883 Eruption of Augustine

Reference #1631:

October 6, 1883. About eight o'clock in the morning on Oct 6, 1883, residents of English Harbor heard an explosion and observed dense volumes of smoke rolling from the summit of St. Augustine Volcano.

Reference #2220:

October 6, 1883. A tsunami was triggered by the sudden displacement of a large volume of seawater from the impact of a debris avalanche at the north shore of St. Augustine Island. This eruption and debris avalanche of St. Augustine Volcano in Cook Inlet, southcentral Alaska traveled ~5 km into the waters of the Cook Inlet. Half of the avalanche travel distance was beyond the pre-1883 shoreline, which was extended to 2 km.

Reference #239:

October 6, 1883, 19:04 GMT. Before the eruption on Augustine Island, seven or eight Aleuts had landed to hunt otter during the winter...After the eruption, no trace could be found of the hunters.

Augustine has had six significant eruptions: 1812, 1883-1884, 1935, 1963-1964, 1976, and 1986. Only the 1883 eruption produced a tsunami.

Reference #2099:

October 6, 1883. Bathymetry (NOAA Hydrographic Survey H-09073) indicates that the avalanche traveled an additional 2.5 km beyond the present shoreline. Modeling suggests that the waves traveled at speeds of up to 100 km/hr and generated by the debris avalanche was as much as 30 m high when generated at the leading edge of the debris avalanche and attenuated to heights of 7-9 m as the wave traveled toward the Kenai Peninsula and mainland Alaska.

Reference #2223:

The waves inundated houses built along the beaches and carried away fishing boats. Thankfully, the tsunami occurred at low tide minimizing the impact in the Cook Inlet. It is possible that there may have been Aleut casualties during this event (a search for five or six Aleut hunters camped on Augustine Island just prior to the eruption yielded nothing) but the descriptions are unclear; the death designation here is conjectural.

Reference #4220:

October 6, 1883. An eyewitness account from English Bay notes minor ash fall occurred at the same time as the tsunami arrived. This ash fall cannot have been a product of the same eruption that generated the tsunami, as ash would have traveled more slowly than the tsunami wave. The minor ash fall at English Bay that began at about the same time as the tsunami lasted only ten minutes and is interpreted as having been generated by a small precursory eruption a few hours before the tsunamigenic events. There are additional accounts of a much larger ashfall starting at 11 am and lasting all day.