Every once in a while, something we thought was lost to the mists of time resurfaces. This is the case with a film of the 1917 eruption of Lassen Peak in California. Up until recently, we only had a few dozen still photos of the volcano erupting between 1914 and 1917. Those photos were a treasure trove of information about the most recent eruption at Lassen Peak, but when it comes to volcanoes, few things beat actual film of the eruption in action.

However, about a year ago, a film emerged of the 1917 eruption of the northern California volcano (above). This film was made by J.J. Hammer, a resident of Red Bluff, California and was possibly released on 1918 as part of a film on the (then) new Lassen Volcanic National Park. It captures some amazing footage of Lassen Peak steaming and erupting, along with brief glimpses of the summit crater itself. Having film means we can see the volcanic processes that happened during the eruption—no more is it just a single moment captured, like in a still photo.

So, what can we see in this brief film? First off, it isn't entirely clear when this film was taken. Dr. Michael Clynne from the U.S. Geological Survey's Volcano Science Center (and probably the world expert on all things Lassen) thinks the footage in the film spans from 1915 to 1917 (possibly later), with much of the real eruption footage coming from 1917. The activity in 1917 was really the waning phases of Lassen Peak's last eruptive period, so these images might be capturing the last gasp of the volcano before going back into repose. The vantage point is near what is now called Reflection Lake (but was Catfish Lake at the time), which is to the north of Lassen Peak, somewhat near where the eventual entrance to Lassen Volcanic National Park is today.

J.J. Hammer/Shasta Historical Society (Annotated by E. Klemetti)

The films opens with the volcano merely steaming (above) but this first segment is likely two different time slices. Before 0:16, the volcano shows evidence of a mudflow on the slope, so likely this was taken after May 1915, likely sometime in the summer. At about 0:16, the shot changes to one with no evidence of that mudflow. The color of the plume (mainly white) supports the idea that this might be mainly water vapor escaping from the heated summit area rather than any eruption. Without any evidence of the mudflow, Dr. Clynne thinks this could be from almost any year between 1914 to 1917.

J.J. Hammer/Shasta Historical Society

Afterwards, we get a quick glimpse at the summit crater of Lassen Peak (above) during this period. Now, any ascent of the volcano when erupting is pretty daring. The shots don't reveal a lot of detail beyond some of the new ash and lava from the eruption. The steam in the background is coming from a crater formed in June 1917. As Dr. Clynne points out, this crater wasn't from an eruption driven by new magma erupting (as what happened in May 1915) but rather a steam-driven blast caused by water seeping into the still-hot volcano's summit area.

J.J. Hammer/Shasta Historical Society (Annotated by E. Klemetti)

Now we get into the real action: Lassen in full eruption (above). The film shows a fresh explosion from Lassen Peak with a fairly vigorous ash plume with obvious pulsing/jetting of ash from the crater. Dr. Clynne thinks these blasts are likely from just after the May 22, 1915 eruption as the Manzanita Creek mudflow is still visible but unlike May 22, these too are stream-driven blasts that are shattering pre-existing lava to create the ash. At maximum, I estimate that the jetting plume is only a few hundred meters (up to ~1000 feet) tall over the volcano before begins to drift with the winds to the south (and continue to buoyantly rise to maybe 1000+ meters/~3,000 feet?).

Now, what I find most interesting is what is happening on the southern slopes. Below the dark grey ash plume is a whiter plume that seems to be coming from the slopes of Lassen Peak. The volcano was heavily snow-covered during the spring of 1915, so this might be steam coming from possibly from a hot mudflow moving down the slopes.

J.J. Hammer/Shasta Historical Society (Annotated by E. Klemetti)

This explosion doesn't last too long. Only a few minutes after it began, the plume is diminished greatly (above). The eruption of Lassen Peak wasn't very large or long, so this makes sense that an individual eruption might have only lasted a few minutes before petering out. The ash plume is still billowing south with white steam coming from the slopes.

Lots of details can be discerned during this films ... and speaking of films of volcanic eruptions, this is pretty early for any film of a volcano. With the help of Matt Dessem (Slate contributor and author of The Gag Man: Clyde Bruckman and the Birth of Film Comedy), I tried to figure out what is the earlier existing film of any volcanic eruption—and this is no easy task. This film of Lassen Peak was made in 1915-17 and from what I can tell, this is clearly the earliest known film of any erupting American volcano. The next oldest is footage of Kilauea erupting in Hawai'i in 1918.

Elsewhere, things get complicated. There are references to films of the eruption of Vesuvius in 1906. However, both films (by Biograph and Edison) appear to have been faked, instead filmed on miniature table top sets. These films are likely almost impossible to watch, but Dr. Boris Behncke pointed me towards a few brief moments of film from the 1906 eruption (starting at 2:22) that shows Vesuvius erupting and a horse-drawn cart moving down an ash-covered street.

At attempt by British & Colonial Kinematograph may have been made to film Vesuvius erupting in 1914, but there doesn't seem to be any other evidence of an actual film being made. A possible film by Urbanora of Semeru in Indonesia may have been taken in 1909, but it doesn't seem that that film exists anymore either.

So, where does that leave this Lassen Peak eruption film? Based on what I could determine, this might be the second oldest existing film of an erupting volcano—and it might be the most complete film in existence from pre-1920 (even if it is evidently missing over 18 minutes of its original run length!)

That is pretty amazing! Not only does this film capture one of only three eruptions in the lower 48 states in the 20th century, but it is one of the first in a long line of volcanic films that capture the majesty and awe-inspiring views of an eruption.

[Thefilm of the 1915 Lassen Peak eruption is courtesy of the Shasta Historical Society. Special thanks to Dr. Michael Clynne from the USGS and Matt Dessem for help in researching this post. Thank you to the Lassen Volcanic National Park and the Sacramento Valley Museum for bringing it to my attention]