A Volcanic Experience: Interning For DEVORA

[Editor’s Note: Today we hear from one of our most experienced DEVORA interns, Maneesha Sakamuri. We occasionally take on students as unpaid interns at DEVORA in exchange for providing research experience and mentorship. Thus far, the training and experience received has led to paid work opportunities and postgraduate projects and support. If you are a geology student at the University of Auckland interested in getting some practical experience, please inquire at env-devora at auckland dot ac dot nz. Even if an internship position is not available, there is always room for more excited volunteers in our DEVORA Outreach Group. Check out some of our previous events around Auckland.

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This is Maneesha, DEVORA intern extraordinaire. She is a 3rd year undergraduate student at the School of Environment at the University of Auckland. When she isn’t interning, getting an award for her Girl Guiding, comfortingly offering to get me mugs of tea, or acing her exams, you can find her perfecting her Taylor Swift dance moves.

Take it away, Maneesha!]

I’d like to tell you the story about how I came to work with DEVORA and what I do as a DEVORA intern.

One day last year while hanging out with a friend, she told me about how she volunteered as an intern for the DEVORA (Determining Volcanic Risk in Auckland) project. Auckland is a geologically active place and is situated on top of an active volcanic field. This puts its 1.5 million residents at risk if an eruption was to occur. DEVORA allows researchers of multiple disciplines to come together with their findings and effectively find solutions to mitigate the volcanic risk. My friend Moira (Fig 1) told me that the work she did with DEVORA had given her a deeper knowledge and skills in the geological field.

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Figure 1 Former DEVORA intern and my friend Moira Poje

Since Moira was heading back to America after her study abroad was over, and because I was interested in the work DEVORA was doing, she arranged for me to meet her supervisor, Elaine Smid, to see if I could also volunteer. As soon as I met Elaine she was so kind, welcoming, and knowledgeable. [Editor’s note: I do not in any way pay or encourage her to say these things, though of course they are 100% accurate and now I think I may owe her some chocolate.] She gave me a general outline of what DEVORA does and asked me to write up the reasons why I was interested in volunteering. From there I went and researched the project. Over the next couple of days I applied to volunteer and obtain new skills as a geologist as well as a researcher. After a couple of weeks Elaine got back to me to confirm my position. This was the most joyous moment of my semester 1 exams season in 2014.

I officially started at DEVORA on the 2nd of July. After Elaine gave me an overview presentation, I truly began to understand what DEVORA does. The presentation described DEVORA’s three research themes: geological, hazard, and risk and social. These are combined to figure out what the volcanic risk is to Auckland. Research findings are used by DEVORA partners to make policies and emergency plans if an eruption was to occur–which is extremely important to save lives and because keeping Auckland running is vital for the NZ economy.

My first few tasks were to help improve and edit the DEVORA website, making Field Note templates, and to help compile the year-end quarterly report. I was invited to shadow senior researchers, who go to schools to teach children about the Auckland volcanoes. Researchers talk about how volcanoes erupt and run experiments with them and teach them about the geological processes at work.

Over 60 researchers from different organisations are involved in DEVORA. In order to help them keep up to date with the literature, I add newly published research on topics related to monogenetic volcanism into our EndNote database.

Every month to six weeks or so the DEVORA team collects seismic data from the Rangitoto seismometer to see if there were any earthquakes (Fig 2). This is done regularly because earthquakes are precursors of volcanic activity and can be used to image and learn more about Auckland’s subsurface. I have participated in collecting data as many times as I can over the past last year.

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Figure 2 Maneesha at the Rangitoto seismic station.

Last September I was given the opportunity to contribute a poster for a public outreach event focused on volcanoes in Spain (Fig 3). This meant learning how to use Adobe Illustrator to update a poster to show what the project recently achieved. Understanding how information is presented is a very important skill for my future career.

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Figure 3 2014 Poster for La Noche De Los Volcanes, 2014.

I also helped organise the annual DEVORA research forum. The DEVORA forum is a time the scientists show the research that has been completed over the past year in the geology, hazards, and risk themes of the project. The research projects vary from geophysics, structural geology, geochemistry to modelling these aspects and impact on humans and infrastructure, all of which help inform stakeholders like Auckland Civil Defence, insurance companies, and Auckland Airport. Various partners of DEVORA attend and learn, ask questions, help set priorities for future areas of study, and identify the gaps in the research.

Pupuke and Mt Eden Volcano field trip

A visiting Watson Fellow, Eloise Andry, plus Elaine, another DEVORA intern, David, and I took a field trip to collect small pieces of volcanic rock called scoria for a PhD student in Canterbury at an old quarry at Pupuke Volcano. The Canterbury student is making ash out of this scoria to test visibility during an eruption, and to test road traction of car tires for input to evacuation models and simulations. [Editor’s note: these experiments, using Pupuke ash, are described in the previous post about VATlab.]

We estimated it would be a long, hard afternoon to collect all the samples we’d need. Thanks to the large group of hard workers involved, it ended up only taking 30 mins! Hence we had enough time to play tour guide to Eloise and explore to learn a bit more about Auckland’s volcanoes. The first stop was the fossil forest at Takapuna. Pupuke lava flowed down through a forest, cooling around tree trunks, which then burned away, leaving a hole. It is also interesting as its deposits contain large olivine grains. These could be from the crust underneath Auckland, brought up after being mined by the magma, or picked up from the mantle and carried to the surface (Fig 4). We also visited Mt Eden and saw the large crater at the top, all of the nearby volcanic hills in Auckland, and its volcanic features such as lava flows.

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Figure 4 Olivines from Lake Pupuke.

I’ve done a ton more tasks, too: I have gotten experience preparing rock samples for various geochemical analyses like XRF. I have also helped sampled volcanic deposits and picked olivines out of those deposits for a PhD project. Every day is a little bit different.

My involvement with DEVORA even directly led to paid work for another lecturer at Auckland Uni. DEVORA has given me so much in the past year and I am so grateful to have this opportunity. I learn more and more geological skills that will aid in real life with every task!

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How Many Volcanoes are There in Auckland?

As it turns out, it is very difficult to count volcanoes. When I started with DEVORA in 2008, I was told that there were 49 volcanoes in the Auckland Volcanic Field. Now, there are more, but exactly how many are there? Well, that depends on who you ask.

The honest answer is that we don’t know. That may sound funny–I mean, we are supposedly smart scientists, shouldn’t we know? Our lack of consensus on this isn’t due to our need for lessons from The Count from Sesame Street, but because we all use slightly different criteria to define a volcano. This question is actually quite good to ponder, because it forces us to define what a volcano actually is, and has implications for how we think the field behaves.

When pressed, we usually give an estimate: about 50 – 55 volcanoes. Like I said, in 2008, when I started with DEVORA, I was told that there were 49 volcanoes. Since then, the Grafton volcano was rediscovered under the Med School in early 2011, bringing the number to 50. Later in 2011, Boggust Park, Puhinui Craters, and Cemetery Crater were added to the mix, and some of us now say that the volcano count has been increased to 53. I personally like to say that there are 53 volcanic centres, because that is how many groupings of volcanic features I count, but someone else might see 55 volcanoes, and someone else still may count only 50.

How could the range be so wide? Here are a few reasons why we can’t seem to settle on a firm number:

  1. Some volcanoes have several vents, indicated by craters or scoria cones, within a small area. This is normal for volcanoes, but how close does a vent have to be to others to be counted as a part of the same volcanic centre? Where is the cut off, distance-wise, for this? The perfect example is Puhinui Craters. These three small craters were discovered in 2011. They are within a small distance of one another, so I’m on board with calling them one volcanic centre, and NOT three individual volcanoes. There is a precedent for this: several AVF volcanoes visibly have more than one vent or crater, and are considered one volcanic centre (One Tree Hill, Three Kings, Mt Eden). They probably erupted within the same time period–nothing contradicts this idea so far. But this isn’t the end of the decisions we have to make to figure out how to count this centre: Puhinui Craters are also close to McLaughlin’s Hill. Are Puhinui Craters a part of McLaughlin’s Hill?? Some of us think no, and increased the volcano number count to 53, and some of us might say yes and keep the number as-is at 52. Still others count each crater as a separate volcano and say that there are now 55.
  2. We generally think of Auckland volcanoes as one-shot deals, so if a volcano erupts in almost the same spot more than once, forming a new crater, after some time gap, is it technically a new volcano, or is the old one active again? Rangitoto falls into this category: we can see at least three vents and know that at least two eruptions occurred about 50 years apart. For now, until other evidence surfaces, I consider this to be one volcano, with at least two eruptions. You can use the examples of Purchas Hill and Mt Wellington to see why this can get complicated: these are considered two volcanoes, but are well within the same distance as Rangitoto’s craters are of one other. Also, these two volcanoes may have even been active at the same time. Geochemically, these two volcanoes are very different, so that is why we call them two volcanoes and not one. But is that the correct thing to do?

Hopefully you can see how hard it can be to decide whether or not a crater or scoria cone is an entirely new volcano or part of an existing one.

Will we discover more volcanoes?

Maybe, but probably not! A thorough analysis of Auckland has been done now. There may be more volcanoes that have been buried or eroded away that we cannot see and therefore have gone unrecognized, but there are likely to be very few of them–we would likely see basaltic ash layers in lake cores from several ‘mystery’ eruptions if so. Our ongoing investigations of lake cores and new entries to our borehole database could shed more light on this, however.

Why does it matter?

The number of volcanoes we count does actually …count. We can use it to determine, statistically, how likely future eruptions are based on what has happened in the past. If every ‘volcano’ represents one eruption (except for Rangitoto!), and if we know how old each centre is, we can start to examine how active the field has been over time and start to pinpoint patterns and what may happen during future eruptions.

So the debate about the number of Auckland volcanoes will continue until scientists can agree. Perhaps some day we will settle on a number. Until then, you will likely see the count range from about 50 to 55 (not to mention some other wild guesses out there). And now you know why!

DEVORA in New Zealand Geographic!

That’s right, we have gotten some great press lately–New Zealand Geographic magazine featured DEVORA research and the Auckland Volcanic Field in their latest (Jan/Feb 2015) issue as the cover story! An excerpt of the story can be found here.

Basically the whole of DEVORA was interviewed for this piece, and a LOT of work went into making all the details correct. We worked very closely with the photographers, writer, and editor for almost two years, in fact–I first pitched the story to the editor in March 2013. I’m excited that some of my PhD research is mentioned, and I have a photographic cameo as well. 🙂

I’m grateful to everyone who made it possible. It is a fantastic summary of the work that has been done and showcases all of the great strides we’ve made in DEVORA to unlock the secrets of the Auckland Volcanic Field.

It’s on sale for $15 at many newsstands, and online. The high quality of the photographs alone make it worth the price–I have my copy proudly displayed on on my coffee table right now.

A Photographic Journey Through Wiri Lava Cave, Auckland

Earlier this year, I received an email saying that the Auckland branch of the GeoClub had organised a trip down into the depths of the Earth. Specifically, into one of the longest lava tubes underneath Auckland, Wiri Lava Cave. Not many people get to go down there, and they had secured permits and an iwi blessing to enter the cave–it is locked with a metal grate at the entrance and, until very recently, no one had gotten permission to enter it since 1998!

The GeoClub folks (led by Bruce Hayward, whom I consider the Godfather of all things Auckland Volcanic Field) also arranged for a cave expert, Peter Crossley, to guide us around. These opportunities for adventure are just one of the perks of the job. I’m happy to get to share them here!

Just as an aside, there are lava tubes all over Auckland. Check out how they form:

I excitedly gathered a group of keen volcanologists from Auckland Uni to go. But first, of course, we had to learn some specifics about what we were seeing. Bruce explained how the cave entrance and lava tube we were about to travel through was once covered by a large scoria cone. The cave is still surrounded by scoria. Unfortunately pictures of the original cone do not exist; by the time they took any pictures of it in the 1940’s, parts of it had already been quarried away. The quarry is still there (not pictured).

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Bruce (centre) gestures to help us visualize the large scoria cone that used to be where we are standing, prior to quarrying. Then…we ENTER!

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Some modification of the cave entrance meant that we had ladders to climb down into the tube. Here, my boss (Jan Lindsay) demonstrates that she is so cool, she even wears shades when climbing into caves.

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Jan’s perspective, looking up at us from inside the lava tube entrance.

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My turn to enter the tube! These are lava drip structures just on the inside of the entrance. They formed when the roof and walls of the lava tube remelted from the heat of the flowing lava. (Sorry no scale–each is about a pinky finger width or less.)

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One ladder down, one more to go. After that there is a little bit of a scramble a few meters down even further.

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After which there is a little bit of a duck-crawl for about 10-15 meters before getting to a larger tube where you can stand up.

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After crawling for a bit, it is a relief to enter a large cave tall enough to stand in. Notice the pointy roof–Bruce thinks it is not rounded (as expected) because while the roof was still plastic, flexible, and hot, the weight of the overlying scoria pushed it inward. Sounds right to me! Still no consensus on what that shiny yellow biogenic stuff on the walls is. We need a biologist, STAT!

 

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This was taken looking straight up. The gases and lava tried to push its way through the lava tube roof and scoria to the surface. It didn’t quite make it. This is how horitos form (http://volcanoes.usgs.gov/images/pglossary/hornito.php).

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The walls of the cave are just a thin (maybe a few cm thick?), melted coating of lava, surrounded by pieces of scoria.

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Ropy textures on the cave floor mark the edges of the channels where the lava flowed, and allow you to see ‘high-tide’ marks of where the lava level rose and then drained away on the bottom half of the walls, and the ‘runway’ of the last dregs of magma on the floor. Such amazing textures!!

 

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‘High tide’ marks of the last few lava flows to come through the tube. Or it could be where some of the thin lava cave walls broke off. It also allows you to see how thin the lava coating is.

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There is some graffiti from surveyors in the tube, unfortunately.

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Here I am just before ‘The Squeeze’ and right before my claustrophobia kicks in. It gets quite narrow here. Again, you can see a survey marker above my head.

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Ropy texture of the tube floor.

 

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Upon turning around and heading back to the surface, Jan took an alternate route through a small channel in the lava tube.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

There are a lot of lava tubes in Auckland that are publicly accessible, though not as extensive as this one. Rangitoto, for example, has a few if you are brave and prepared enough to explore them while you are over there!

It was a really great day exploring this hidden geological wonder right here in our backyard. I just want to thank the Auckland GeoClub once again for arranging this truly exciting, one-of-a-kind outing. Happy lava-tube exploring!

A volcano card game!

I love volcanoes. And I love card and board games. So imagine my delight when I discovered that a volcano card game had been invented! In the game you get to learn facts about volcanoes around the world while beating having fun with friends.

It is the perfect gift for anyone that likes games and volcanoes (hint, hint). All profits go to help those affected by volcanic eruptions, as the game was designed by the geologists and volcanologists affiliated with the STREVA project and distributed as a part of the Top Trumps series. You may even see a familiar New Zealand volcano in the mix!

http://volcanoestoptrumps.org/home-page/get-the-cards/

That card game has now been turned into a free digital game online! You do have to register (for free) to Top Trumps.

Happy learning and playing!

Moving Parliament: Wellington Earthquakes to Auckland Eruptions

Recently, NIWA scientists unveiled the discovery of a ‘new’ faultline in Wellington during investigations conducted by our sister project, It’s Our Fault. Prime Minister John Key was asked whether Parliament should be moved to a different city to try to mitigate the chaos that would certainly ensue if a large earthquake occurred under Wellington. Campbell Live jumped on the train shortly after, asking for the public’s opinion of a Parliament move to Auckland on Facebook and Twitter:

Protests of ‘but what about all the active volcanoes in Auckland?’ immediately erupted:

We’d be going from the frying pan and into the fire, is what many are thinking. But would we? That Auckland’s volcanoes could erupt again is one of the most common misconceptions I hear. Here’s what the evidence says: the Auckland Volcanic Field itself is dormant, but the individual volcanoes in it are extinct. This means that we expect eruptions to happen in Auckland in the future. It just won’t be at an existing volcano (with the exception of possibly Rangitoto (that sordid story here)).

For an existing Auckland volcano to erupt again, there has to be an established pathway from the magma source in the mantle to the volcano, and possibly a magma chamber, stewing away, underneath. We have absolutely no evidence that any magma chambers exist under any Auckland volcanoes.

Sketch of a magma reservoir and conduit beneath a volcano

Magma rising through the crust to the surface, pooling in a magma chamber before erupting. We have no evidence that magma is hanging around under any Auckland volcanoes. Sketch by B. Myers, image credit: USGS, http://volcanoes.usgs.gov/images/pglossary/magma.php.

We think that in volcanic fields such as Auckland’s, the magma pushing its way to the surface perhaps cools and ‘seals’ up the route that it took. This blocks future batches of magma from taking that same route, as later magma batches find it much easier to push through soft sediments than hard, cool lava.

In Auckland, there just doesn’t seem to be enough magma rising to keep the connection open to feed the same volcano over and over again. This results in a field of many small volcanoes instead of one single, large volcano.

So, the volcanoes in Auckland seem to be one-shot deals.

I am certainly not advocating a move, and an Auckland-based Parliament would be threatened by future eruptions in the field, but Auckland may be a bit safer from those 55 volcanoes than some think. So, does this change your opinion of a move?

Flying Over Auckland

Late last year, I had the good fortune to meet a trained pilot who volunteered to take me and my flatmate up in his plane over Auckland. I’ve always wanted to do this–and in fact had investigated flight prices ($199 for 15 minutes?! Ouch!)–so leapt at the opportunity. We were up there for a few hours on a beautiful early summer day, flying from south Auckland around to Rangitoto and Whangaparaoa, then to Devonport and over the Harbour Bridge and behind the Sky Tower. It was exhilarating. Flying is one of my absolute favourite things to do–if I had the time and money, I’d definitely take pilot lessons.

As always, I had my geologists’ cap on. The trip offered some great vantage points to see Auckland’s volcanoes and geology like I’d never seen them before:

(All photos by Elaine Smid. Feel free to use with proper citation and reference link back to me and this blog.)

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After taking off from Ardmore, we flew towards Motukorea and Rangitoto Volcanoes in the Waitemata Harbour.

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Here we can see right into Motukorea’s scoria cone and envision how the lava flows rafted some of that scoria away from the top of the cone (resulting in those bumps seen on the flanks).

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Clouds moved in as we came closer to Rangitoto’s Central Crater.

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Rangitoto’s Central Crater with boardwalk and overlook platform visible.

Looking back at the city and North Shore from the north.

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Freshwater Lake Pupuke, which formed in craters created by eruptions, shines in the sun. There are two round, overlapping explosion craters visible, one much smaller and closer to the camera and sea, and the larger one behind it.

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Lake Pupuke surrounded by the North Shore, with the city in the left background.

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Sprawling Rangitoto Volcano.

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Auckland: City of Volcanoes

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Rangitoto in background, North Head Volcano in foreground.
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The City and her volcanoes.

What a fabulous trip! I wish I could do that every weekend.

All photos by Elaine Smid. Feel free to use with proper citation and reference link back to this blog.