Where there's smoke...

Of course, Kilauea isn't just a volcano that erupted recently, its a volcano that is erupting.  The most active volcano on the planet is erupting near constantly. Just not quite as much as normal when we were there.  Normally there is one crater down on the East Rift Zone that you can see a lava lake, and a fissure that opens up near the sea where the lava pours into the ocean. Very photogenic stuff and great for tourism.  But Pele (A Hawaiian goddess who's nominally in charge of volcanoes and fire, not that the Hawaiian gods and goddesses are gods of anything the way the Greek and Roman ones were) is her own master and isn't always obliging.  Occasionally obliterating villages and destroying roads and occasionally not doing very much at all.  In early March, there was a burst of activity, which saw a small collapse in the East Rift Zone, the lava lake shrank back into the volcanic vent and the far eastern fissure stopped erupting.  So there was nowhere to watch lava whilst we were there.  A bit disappointing but still...

It is an active volcano, and active volcanoes do tend to smoke a bit, even if there isn't lava coming out. Which is still pretty damn cool.  An boy does Kilauea smoke.  There's been elevated sulphur dioxide levels in the National Park for a couple of years, indicating that something is going on. Half of the park (luckily the more boring half) is closed to visitors.

This is the view across, the small side crater at Kilauea, with the big one stretching off into the distance.

Then at the end of the day, after cycling around the park, we took a quick drive round to the other side of the crater/caldera in the fading light.  In the photo above, the circular thing is the crater. Pretty much everything in shot is the caldera, its about 3x5km. With smoke rising up above, and as darkness fell, we got an unexpected treat.

Whilst you might not be able to see the lava (its a couple of hundred metres below the surface in the vent), you can see the glow of the lava, bouncing off the smoke plume. Its so awesome! And as it gets darker (and colder!) the light gets brighter.  Luckily there's a pretty damn good museum on the caldera rim (along with the Hawaiian Volcano Observatory) to keep warm and entertained in between just standing outside and watching the amazing glow. A little view into the earth's interior (kind of).

Plus, as a little aside, the flanks of Mauna Loa, which sits above Kilaeua, have started expanding.  Something is brewing under big island and its probably magma!

Baby Rocks

As a geologist I'm fairly used to dealing with rocks that are millions, or hundreds of millions, and occasionally billions (I have held the hand-sample of the Jack Hills Conglomerate which contains the oldest minerals on Earth at 4.4 billion years old but thats another story!). But things on Hawaii are a little younger.

This is the youngest lava flow on Maui, known as the 1790 flow, because the maps of the island made in 1791 were different from those made by Captain Cook in the 1770s. It might actually be older than that, the maps may not be accurate.  But it was around then.

For the second part of the trip we moved on from the dormant volcano of Maui and onto the active volcanic island of Hawaii, also known as Big Island, when distinction is needed between the island and the chain of islands. We went to Kilauea volcano, the most active volcano on earth (unfortunately not spewing lava when we went) which have baby rocks (note: not a technical term), some only a few weeks old.  All together now: awwwwwww.

Hawaii is a shield volcano.  As the lava is so runny you don't get the iconic cone shapes that build up on more stereotypical volcanoes.  And they tend to erupt for longer periods of time.  As a result the lava spreads out over large distances, forming a shield shape.  This can mean that, in places the volcano isn't that tall and is relatively flat.  Kilauea is a bit like that, dwarfed by Mauna Loa and Mauna Kea above it which have built up higher as they are older volcanoes. This means its possible to cycle around Kilaeau National Park and go and see the sights by bike, rather than trapse around by car.  It was a well needed break from the car, and meant we got to on some of the tracks round the park where cars can't go and had some of the park to ourselves. Especially when we came across this on a lava flow that dates to just 1973 (or so).

 Its a volcano monitoring station. With super-accurate GPS units, gas monitoring, tilt-metres and the like, all designed to measure tiny changes in the volcano's shape and output that give little clues as to location and movement of magma deep below the ground.  This is how geologists predict eruptions!

Of course there are some parts of the park where you can't go.  Some due to current or potential volcanic activity, others because of past activity:

 I'm used to road cuts through rock providing useful geological outcrops.  But here the rock has revenge, the 1973 lava flow has reached the road here, and behind it has completely covered it over. How cool is that?!

 In the background above is the 1973 flow, in the foreground, part of the 1969 flow.  The crack running down the left with the trees next to it is the fissure from which the lava erupted.

 Me above the fissure!

 More views of recent lava flows

 The 1973 flow, barren, rocky, almost alien, but very very cool!

Igneous Speleothems? Dark goings on inside lava tubes.

On the island of Maui, and also Big Island, in Hawaii there are lava tubes.  We visited the biggest one on Maui for a bit of a look around. Lava tubes are, as the name might suggest, tubes made of lava! When lava flows flow downhill the outer surfaces cool, solidify and harden as they're exposed to the atmosphere. Typically the top surface of the flow is put under stress from the flowing lava beneath and it breaks up and rejoins the flow.  Thus many lava flows form their own levees which channel the flow downhill. This is fairly normal. Sometimes, however, the top surface doesn't break up and it too cools and hardens forming a solid crust around the flow.  Since rock is a fairly good insulator the inside of the flow remains warm and gooey and continues to flow through underneath the crust.  If all of the flow comes out at the far end then you're left with a hollow structure known as a lava tube. Overtime more flows might flow through the tube, cooling and thickening the walls and cutting deeper down into the bedrock beneath, so these things can become quite large with all sorts of erosional and depositional features you might expect from caves made by the erosional power of water

Lava tubes even have speleothems (that's stalactites and stalagmites) although they form in a completely different way to the limestone ones which I study.

Descent into the lava tubes

The way down

Chocolate brown stalactites

Stalactites are pretty common, formed when the dropping lava levels form drips on the upper surface, that cool and solidify.  It is even possible that proper calcite speleothems begin to grow over the top of them from water running down through the cave system, getting through cracks formed as the walls shrank as they got cooler. But the lava tubes are generally too recent to get any decent paleoclimate data from as the stalactites haven't had long enough to get very big.

Stalagmites!

Stalagmites can also form, but this is much rarer. The ones in the photogragh above are about forty centimetres tall. These stalagmites also form from dripping lava, typically from a fresh lava flow over the top of the lava tube seeps through cracks in the tube and drops down into the empty tube.

The green and coppery colours that you may just be able to make out in this photograph (its a lot more obvious in real life) are chemolithotrophs.  They are organisms (typically bacteria) that get their energy source not from the sun (either directly or indirectly as most of life does) but from the rocks.  These guys literally feed off of the rocks and use chemical reactions of the compounds inside to generate energy.  Plus there are all sorts of former surface organisms that have become specialised to caves, gone white, and lost their eyes and such like, but these are quite rare, as you may imagine.

Typically the last lava flow to flow through the tube is a piddly little affair. It runs down through the centre of the tube, the sides of it cool and form levees which channel the flow.  As a result you sometimes get these bowling alley type formations running through the middle of the tubes.

Lava tubes are pretty damn cool to visit, hopefully the limestone ones that I'll be off to in five weeks time or so will be just as entertaining.

Haleakala: volcanoes, oceans and ice?

Haleakala is the the main peak on the island of Maui in Hawaii, covering 75% of the island's area. Its a dormant volcano, having last erupted in 1790, possibly, depending on wherther Cook's naval charts were accurate or not. Its 3055m tall, quite impressive when the surrounds are so flat (being the Pacific Ocean), so just enough to potentially trigger some altitude issues. Certainly high enough to be freezing cold at night. We drove up early one morning having camped at the base in order to watch the sunrise and then go for a hike around the summit area. It was possibly my favourite day of the entire trip.

The moon and Venus become the last two lights in the sky as the dawn approaches.

Nearly there.

3....2.....1................

First light.  Accompanied by native Hawaiian chanting and conch shell trumpeting. A pretty important site, the summit depression is home to the Grandmother of the demigod Maui (its a bit like discovering just how people there are in the Royal family when you start learning about the relatives of demi-gods). Haleakala translates as "House of the Sun" and you can see why.

The first decent view of the "crater" or is it a "caldera".  Its a shield volcano, so the lavas too runny for a decent caldera. And its quite big for a crater. So what could it be?

The descent down, with some fantastic colours in the early morning light, reds, oranges, purples, browns, greys.  Rather cool, and quite Martian in appearance.

Though not devoid of life.  This is a silversword, a protected species that is only found towards the top of the Hawaiian volcanos.  It lives for up to fifty years, flowering once before dying.

More views across the "crater" floor.  Cinder cones of recent eruptions litter the top, with the steep ring wall surrounding them.  This area was a lot lot bigger than it first appeared at dawn. And so awesome!!!

More views across the floor, with recent (ish) lava flows spread out like a rocky drapey thing. So what is this big depression if its not volcanic in origin?  It turns out to be erosional, two large valleys that lead off each end of the depression eventually eroded through the rock wall that divided them to form the large valley at the top.  It might even have been eroded through by ice during the last ice age (the volcanoes are just about high enough to get ice-caps during ice-ages).  Speaking as a geologist this is really cool.  Not only is this a volcanic landscape, but it might also be a glacial one too! All at less than 21 degrees North of the equator.  Wow!

As we descended we moved towards the northern side of volcano and the valley that leads up from the sea.  Due to the near constant trade-winds in Hawaii the wind direction is nearly always from the north-east.  Being the only change in elevation for thousands of miles there's a lot of cloud and rain when the moisture-laden winds hit the side of the mountain, rise, cool and deposit their rain on the slopes of Hawaii.  As a consequence, the northern and eastern sides of the Hawaiian islands are wet, lush, tropical rainforests with waterfalls and the like.  The United States' wettest city is Hilo on the northern coast of Big Island. The southern and western sides of the islands are far more barren, rocky from  lava flows, or just grassy where there is vegeation.  A real diffrence, quite striking when you drive round the islands and the flora changes so quickly. So as we descended into the valley, the mist and cloud came up to meet us, and the place slowly but surely got more and more vegetated as we descended.  But there were still rocky lava flows here and there to cross.  It was quite a surreal terrain to traverse.  The hike ended with a climb up the steep tracker that lead up the "crater" walls back to the rim.

Back at the top at the end of the hike (and a lift back to the top), looking out towards big island and the volcano of Mauna Loa.

Stal Polishing

Previously on "My PhD", we went to Tumut to get several stalagmites cut.  Then we drilled little pieces out to analyse them on the Krystalloflex to check whether they were calcite or aragonite and also sent some samples off to be dated.  Over these couple of weeks I'm spending a few afternoons polishing the slabs we cut out the middle of the stalagmites.  This involves a polishing device which rotates different grade polishing things (or some such technical explanation, its late and I'm tired).  Its attached to a hose so fires high pressure water at the same time in that water and electricity mix that makes me nervous.  There are seven grades of polishing to get the slabs level and get rid of bumps and scratches and then to polish so that they are nice and smooth, and shiny even when dry.  It takes ages.  These three pieces took two and a half hours to polish both sides.  Its quite tiring because the machine is uncomfortable to use and the hose isn't that well connected so it occasionally comes off and sprays me in the face and gets me soaking wet.

 This is what the stal slabs look like before:

And this is what the stal looks life afterwards.  Actually it doesn't look much better in these pics I'll admit.  But it really is easier to see all the deatils, theres contrast and the layers are much sharper, and you can see more sub mm structures.  All of this is very good.

So we now can analyse the stal structure in more detail, we can tell better where things are going on such as changes in structure, hiatuses in stalagmite growth.  Having a level smooth slab also makes it easier to drill consistent powders down the middle when we get to that stage.  What I need now are some dates so I can work out exactly which of the collected stalagmites I need to use.  Unfortunatly this bit is outsourced to Melbourne. And so we wait.

Eden

So I've spent the last week down on the coast around the town of Eden, close to the New South Wales/Victoria border (about three to four hours drive from Canberra, five taking the long route).  I was demonstrating on the first-year undergraduate field-course.  It was a lot of fun.  It was sunny all week, and warm, we spent most of it by the coast, frequently on nice beaches, a few swims in the ocean (much much warmer than a month ago!) and there were lots of interesting rocks.  But not too complicated, just difficult enough for me to work it out pretty quickly and the undergrads to puzzle over for a while! Plus there was some not so excellent, followed by excellent, followed by not so excellent followed by excellent cricket going on!

There were three of us postgrads demonstrating (myself, EG and BH - both of whom I get along very well with) along with a plethora of some big names in geology, which was rather cool. One thing that was disappointing was the undergrads reluctance to drink.  Having a beer or two during the evening session's lectures and work is pretty standard for geologists.  These kids need to learn! They were a good bunch really!

We finished the week by driving back up the coast for a beach party to celebrate LB's (another departmental first year grad) birthday.  And a good time was had by all. In the morning it decided to rain, so we fled back to Canberra, where it genuinely hasn't stopped raining since.  Its meant to be summer now.  Sigh!

Loads of photos, enjoy!