A variety of holes in lava
Holy lava, geoblogosphere!
On my recent trip to Hawai'i, I saw a variety of different kinds of holes in the basaltic "lava rock" that makes up the majority of the island. The largest examples were lava tubes, like the Thurston Lava Tube near Kilauea Iki in Hawai'i Volcanoes National Park:
This is a conduit through which molten lava once flowed. Once the source of that lava ceased producing, though, the lava drained out and the tube was left empty, like a cave. (Caves, of course, are holes produced through an entirely different process.) The ceiling of this lava tube is about twenty feet high.
Not too far distant, there's a nice area where you can see tree molds:
These are holes left in the rock as the lava flowed around a tree. The heat of the molten rock burst the tree's cells, releasing water and quenching the lava in a cylindrical tube around the tree. The dewatered tree then burned up, leaving a hollow mold showing the shape of its (former) trunk:
The holes are kinda deep:
Inside the tree mold, you can see the texture of the (in this case, pahoehoe) lava that flowed around the tree trunk:
Looking up the invisible tree trunk, and out the hole towards Lily:
Here's a bigger hole, the Halema'uma'u Crater within Kilauea Caldera:
It's venting a lot of steam, hydrogen sulfide, and other gases.
Google Map for reference on how this hole relates to the even bigger hole that is the caldera:
The photo of Halema'uma'u above was taken from the Hawai'i Volcano Observatory adjacent to the Jagger Museum in the park. Stepping back a bit from the window, you can see that I'm not the only one taking this particular photo... This is the same spot where the Halema'uma'u Crater webcam is filmed. That's what all these cameras are doing in the foreground:
Janet Babb took some time out of her day to show us around the place (thanks, Janet!), and I made sure to sign into the guest book. There, I was pleased to see past visitors, including (I think) Ron Schott's crew fromFort Hays State University Lake Superior State University, the William and Mary crew, and most recently, the NOVA crew headed by my colleagues Ken Rasmussen and Nancy Chamberlain:
Janet let me hold a chunk of recently erupted basalt. This one erupted in early October, I think she said. It was about a month old when I held it -- that's my record for a really recent rock:
As noted in a previous post, this vesicular texture displayed by this sample is one more example of (smaller) holes in lava.
On my recent trip to Hawai'i, I saw a variety of different kinds of holes in the basaltic "lava rock" that makes up the majority of the island. The largest examples were lava tubes, like the Thurston Lava Tube near Kilauea Iki in Hawai'i Volcanoes National Park:
This is a conduit through which molten lava once flowed. Once the source of that lava ceased producing, though, the lava drained out and the tube was left empty, like a cave. (Caves, of course, are holes produced through an entirely different process.) The ceiling of this lava tube is about twenty feet high.
Not too far distant, there's a nice area where you can see tree molds:
These are holes left in the rock as the lava flowed around a tree. The heat of the molten rock burst the tree's cells, releasing water and quenching the lava in a cylindrical tube around the tree. The dewatered tree then burned up, leaving a hollow mold showing the shape of its (former) trunk:
The holes are kinda deep:
Inside the tree mold, you can see the texture of the (in this case, pahoehoe) lava that flowed around the tree trunk:
Looking up the invisible tree trunk, and out the hole towards Lily:
Here's a bigger hole, the Halema'uma'u Crater within Kilauea Caldera:
It's venting a lot of steam, hydrogen sulfide, and other gases.
Google Map for reference on how this hole relates to the even bigger hole that is the caldera:
The photo of Halema'uma'u above was taken from the Hawai'i Volcano Observatory adjacent to the Jagger Museum in the park. Stepping back a bit from the window, you can see that I'm not the only one taking this particular photo... This is the same spot where the Halema'uma'u Crater webcam is filmed. That's what all these cameras are doing in the foreground:
Janet Babb took some time out of her day to show us around the place (thanks, Janet!), and I made sure to sign into the guest book. There, I was pleased to see past visitors, including (I think) Ron Schott's crew from
Janet let me hold a chunk of recently erupted basalt. This one erupted in early October, I think she said. It was about a month old when I held it -- that's my record for a really recent rock:
As noted in a previous post, this vesicular texture displayed by this sample is one more example of (smaller) holes in lava.
1 Comments:
If you saw my name in their book it was from January 2004 - just prior to my last semester at Lake Superior State University (LSSU). Someday I'll get the FHSU students out there!
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