January 2, 1996 Tsunami: Karymskoye, Kamchatka, Russia

A volcanic eruption in the Karymskoye freshwater lake in eastern Kamchatka began in the afternoon of January 2nd and continued for about 10 to 20 hours. The initial observation from an over flight at 15:40 LT showed that the ice cover of the lake had melted and a phreatomagmatic eruption was in progress from a vent off the northern shore of the lake in a water depth of 40-50 m. Explosions occurred every 4 to 12 minutes. Six explosions were observed with an average interval of 6 minutes between them. Between explosions the lake water displayed intensive bubbling and steaming. The strongest explosions produced a rapidly rising, smooth-surfaced bulb-like mass of expanding gas and pyroclastics. This bulb grew to a height of 450 m, and then it began to collapse as jets of black pyroclastics mixed with steam pierced the shell. A light gray "collar" appeared around the center of the explosion about 130 m high. This collar propagated radialy about 20 to 40 m/s to form a tsunami. Meanwhile the pyroclastic jets reached their maximum height of 1 km and collapsed back into the lake to produce a base surge. The interaction between the base surge and the lake water contributed to the formation of complex waves.

The steep northern shore of the lake was violently eroded by the tsunamis and surges, with all plants and soil less than 1.5 m thick stripped off, and poorly consolidated bedrock exposed. Along the rest of the shoreline, more than 1.3 km from the crater, the tsunamis carved new cliffs two to three meters high, eroded the layer of frozen soil up to 50 cm thick, and removed the vegetation. The tsunamis deposited several discontinuous, finely laminated layers of sand and gravel up to 35 cm thick, with scattered pebbles, and fragments of plants. The strongest event produced the highest runup of 30 m on the shore 700 m from the center of the crater. At the most distant points (1.3 km from the crater) the runup was two to three meters.

(above from reference #1315)

The highest runups (20-30 m) occur on the shore immediately adjacent to the tuff ring, 700 m from the center of the crater. [29m according to Figure 1] (reference #2422)

During the eruption, jets of black mixtures of pyroclastic material, steam and water erupted from the lake every 4–12 min with heights of up to 1 km (Muravyev et al., 1998; Belousov et al., 2000). The eruptions and the collapses of these jets formed tsunamis, with wavelengths of 100 m and runup of up to 20 m on the northern-western shore, which damaged the shoreline more than 1.3 km away from the source, eroded soil up to 0.5 m thick and carved new cliffs up to 2–3 m high (reference #13829)