We woke up earlier than usual today to the disappointing news that our previously scheduled trip to White Island would not occur due to inclement weather. However, Darrren, Guil, and Lydia had another exciting day planned for us: visiting The Redwoods in Rotorua, a giant California Redwood Forest. We piled into the Cube van and the smaller Subaru outback and enjoyed a very scenic, hour-and-a-half long ride to Rotorua, with some of the music from Harry Styles new album. When we got to Rotorua, we stopped at a bakery for some pre-geological snacks. With snacks in hand, we pulled up to The Redwoods and set off on our hike.
After hiking for about half an hour, we reached a scenic outlook, overlooking the entire basin of Lake Rotorua. Here we learned that the ridges we were standing on were the edges of a 13 km wide caldera. A caldera volcano is one that, after eruption, collapses in on the empty space created by the erupted magma, creating a giant, crater-like area, called a caldera.
We spent some time thinking about how this caldera, and calderas in general, are formed. Darren, Guil, and Lydia led us in a discussion about whether or not all of the magma erupts at the same time. We used the evidence of the geothermal pools we saw below to rationalize that there is still some magma from the volcano that was not erupted and remains below the surface. We did the math, and we calculated that there was about 150 cubic km of magma erupted by the volcano!
The reasoning we came up with for why all magma in a volcano does not erupt at the same time is that different pockets of magma have different concentrations of crystals, affecting the volume of melt and volatiles that can be present in the magma. After obstructing the view of some tourists, we made our way back down the mountain to drive somewhere to have lunch. We saw some mountain bikers going down the trail, but we wasted our time watching them because they didn’t do anything cool.
After enjoying a scenic lunch on the shore of Lake Tarawera, we began a discussion about the Okataina caldera that encompasses Mount Tarawera and how it was the source of the pyroclastic flow deposit we viewed over 40 km (!!!) away at an outcrop on the coast that we looked at yesterday. After some enlightening conversation about different magma and how it is formed, we learned about our mortality at the hands of a 300 m/s pyroclastic flow that could erupt from the Okataina caldera at any moment.
With our hairs unsinged, we made our way back to the Ohope Beach Holiday Park, where we enjoyed a fine dinner of locally-sourced fish and chips, after which we cleaned our clothes and looked up at the Milky Way and Southern Cross in the night sky.
No volcanoes have erupted yet.
-Liam and Henry
After hiking for about half an hour, we reached a scenic outlook, overlooking the entire basin of Lake Rotorua. Here we learned that the ridges we were standing on were the edges of a 13 km wide caldera. A caldera volcano is one that, after eruption, collapses in on the empty space created by the erupted magma, creating a giant, crater-like area, called a caldera.
We spent some time thinking about how this caldera, and calderas in general, are formed. Darren, Guil, and Lydia led us in a discussion about whether or not all of the magma erupts at the same time. We used the evidence of the geothermal pools we saw below to rationalize that there is still some magma from the volcano that was not erupted and remains below the surface. We did the math, and we calculated that there was about 150 cubic km of magma erupted by the volcano!
The reasoning we came up with for why all magma in a volcano does not erupt at the same time is that different pockets of magma have different concentrations of crystals, affecting the volume of melt and volatiles that can be present in the magma. After obstructing the view of some tourists, we made our way back down the mountain to drive somewhere to have lunch. We saw some mountain bikers going down the trail, but we wasted our time watching them because they didn’t do anything cool.
After enjoying a scenic lunch on the shore of Lake Tarawera, we began a discussion about the Okataina caldera that encompasses Mount Tarawera and how it was the source of the pyroclastic flow deposit we viewed over 40 km (!!!) away at an outcrop on the coast that we looked at yesterday. After some enlightening conversation about different magma and how it is formed, we learned about our mortality at the hands of a 300 m/s pyroclastic flow that could erupt from the Okataina caldera at any moment.
With our hairs unsinged, we made our way back to the Ohope Beach Holiday Park, where we enjoyed a fine dinner of locally-sourced fish and chips, after which we cleaned our clothes and looked up at the Milky Way and Southern Cross in the night sky.
No volcanoes have erupted yet.
-Liam and Henry
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