This continues my transcription of the Thurs Jun 28 USGS presentation at Volcano Village. Part 1 transcribed HVO Scientist-in-Charge Tina Neal and seismologist Kyle Anderson’s remarks. Part 2 covers senior volcanologist and my longtime hero Don Swanson’s remarks.
Here’s the video of the entire 1.5 hour meeting. Don’s presentation starts at 15:50:
It sounds like Swanson’s been holed up in Volcano House after HVO was evacuated. (Kyle Anderson: “Don has spent more time viewing this eruption from the summit than anyone else.”)
Title of talk: “Comparisons of Halemaʻumaʻu Crater, May 19 through June 28
Viewed from dining room table of Volcano House”
Don Swanson, geologist, USGS
[15:50] Thanks, Kyle.
The data that Kyle showed are absolutely magnificent. What I want to do now is to show you some photographs of features that I’ve been able to see during my observations. The first will be a series of photographs of Halemaʻumaʻu taken from the seat in the dining room of the Volcano House hotel where I sit and observe things.
On May 19th, of course, things were just starting to get going, but over here on June 13th, you can see that the crater has widened dramatically, and notice that it’s also dropped to the top of the tree which was way below the— it’s come way down. It isn’t because the tree is growing! It’s because the crater is dropping down.
Now we’ll go to this next period, June 13th to the 17th.
You see that the tree is sticking up much higher.
And as of today, here the tree stands way up.
So obviously, the crater is really going down.
I spent some time collecting ash from the buckets that I had in the parking lot at Halemaʻumaʻu. (I’ve given After Dark talks about this process.) On May 14, cracks were just starting to form in the parking lot, and also outside of the parking lot in the adjacent trail out to the Halemaʻumaʻu Overlook.
By June 5, the parking lot was getting very badly disturbed. The curb was being warped. This is an area where… the parking bay was here [points to lefthand side of photo], and this is a median between the parking bays [righthand side]. That was June 5.
On June 11: this is the same crack. It’s at a different place in the parking lot. And it was getting very wide, and there were many more such cracks in the parking lot.
On that same day, you can see that the roadway, which is here [points to bottom/foreground of photo] — in fact, this is the center line of the road [light-colored spot at center]; I just brushed the ash off— the block that I’m standing on to take the photograph was actually going down. So there was an offset there of probably close to ten feet or so.
Now that has changed dramatically. This is that same area, [taken] from a different location, safely back away from the rim. And this is the roadway, here. [faintly lighter stripe slanting from middle to lower left on downdropped area on left side of photo.] If you want to call it a roadway any more.
And this is a normal fault that has dropped the Halemaʻumaʻu side down, and of course that is going to end up in the crater itself very soon.
And this is a photograph [looking south] I took this morning. The arrows show the road [Crater Rim Drive] coming in from Keanakāko’i. The righthand arrow is pointing to a segment of road which is detached from the main road farther east by one of these faults. And so… the parking lot is no more. There’s no doubt about that.
I want you to remember… [a bit of fumbling for a laser pointer that doesn’t work, but indicates the large lumpy/irregular cliff face or scarp closest to us in middle ground, right half of photo] There is a scarp or a fault that forms a cliff that breaks the road. And the next— two slides from now, I want to show you that again.
This is a feature that formed near Keanakāko’i that’s in the upper center of the photograph [dark horizontal cliff/scarp.] That is a big cliff that formed by the caldera dropping down.
That formed between Sunday afternoon and Tuesday afternoon of this week [June 24-26]. That’s an offset of something like probably 30 feet, or something on that order. We don’t know exactly during which one of these big events it occurred, but probably either Sunday night or Monday.
[FWIW, here’s a video capture of Monday’s. I think this feature’s over on the left in the background. It may have dropped more on Monday, or that may be when it formed.]
And the last slide shows the same feature, but with the red arrows showing that it can be extended all the way from where the lefthand arrow is— that was showing the view in the past slide— all the way around and connecting up here with that fault that detaches the parking lot from the rest of the road. So that is a major fault. Currently it is the boundary fault of the area that is dropping down, and the arrows point to the level of the caldera floor before this downdropping began.
So these changes that Kyle so well presented in map views are really obviously very apparent when you’re in the field. And the changes are doubtless only going to get more with time as the event continues.
One final thing— I think I had five minutes and I probably used four and a half so I’ll use 30 seconds — is this an eruption that is taking place at the summit of Kīlauea?
An eruption means that material is rising up to the ground surface from below. Well, for the last couple of weeks, two and a half weeks maybe, we haven’t had any new material, I don’t think, added to the ground surface. Except for gas. The ash has essentially stopped being erupted. Probably all of the material that dirties the plume during the big earthquakes is rockfall dust. Because the earthquakes generate a lot of rockfalls in the crater. Dust rises and then is carried up by the gas that is being ejected during these events.
So… we’re going to keep calling this an eruption, I’m sure, but technically speaking, it’s really interesting that we have an eruption with nothing being erupted except for gas.
[NOTE: I’ve moved the Q&A session to a new post, Part 3, because it’s long. But I found it worthwhile hearing what some of the senior HVO geologists have to say about questions we’ve all asked (and a few we haven’t).]