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An adventure on the Southern Ocean – Part II

Thuany Costa de Lima is a third year PhD student in the Seismology & Mathematical Geophysics group at RSES. Her PhD focuses on investigating the physical properties of the deep Earth structure in the light of seismological tools, from the inner core to the mantle.

In my first post on ‘An adventure on the Southern Ocean’, I talked about the multiple reasons for us to come on this research voyage. Today, I would like to elaborate a bit more on why this is one of the toughest field works a seismologist could ever do, share with you some of the amazing photos of the wildlife we could spot from the boat, and describe the real fun I had while living on a vessel!

Continue reading “An adventure on the Southern Ocean – Part II”

An adventure on the Southern Ocean – Part I

Thuany Costa de Lima is a third year PhD student in the Seismology & Mathematical Geophysics group at RSES. Her PhD focuses on investigating the physical properties of the deep Earth structure in the light of seismological tools, from the inner core to the mantle.

Below 40°S there is no law, and below 50°S there is no God.”

I recently heard this old sailors’ saying for the first time after stepping on-board the Marine National Facility (MNF) Research Vessel (RV) Investigator. I was far away from the Australian mainland, and close to accomplishing a ground-breaking milestone for scientists: using seismology to investigate the 3D structure of the Macquarie Ridge Complex!

Continue reading “An adventure on the Southern Ocean – Part I”

When Science meets Street Art

By Tanja

One of the many events held this year as part of the National Science Week was a collaborative project between scientists and artists. It was called Co-Lab: Science meets Street Art, and it is exactly what it sounds like: scientists and artists pair up, scientists have to explain their project in human terms and artists have to then paint their view of that project on a wall. Exciting, right?! I thought so too.

Continue reading “When Science meets Street Art”

Hilarity ensues – Part I

Or: Why you should do fieldwork

By Tanja

Just under a week ago I came back from a two-week long fieldwork in the bush area of Western Australia. Not sure if that area really counts as the outback as the nearest town (Esperance) was ~300 km from where we were and we were around ~800 km from Perth… I know it can get way more isolated up in the Kimberleys apparently. So anyways… before I tell you a few short stories about interesting things that happened let me tell you something about this fieldwork itself and why we went there and back again.

In seismology we collect our data by downloading a bunch of seismograms and then processing them in some way – which varies depending on what you need to extract from them. In order to have seismograms you need seismometers that will record earthquakes from around the world. There are plenty of these distributed around the globe and data is readily available.

map
Figure 1: Project area and the array in question. On this particular trip we serviced/installed all the stations shown in either half-red or full-red symbols.
Courtesy of Christian Sippl.

But sometimes you maybe want to study a specific region or a particular structure within the region – this is when you need a seismic array (usually in some shape – elongated, circular, L-shaped, spiral…). There are a lot of global arrays (one of the most popular being the moving USArray) but sometimes you don’t have arrays where you need them. And that is when you have to physically install them. One such array has been installed around ~2013 in remote regions between Esperance and Kalgoorlie in WA (Figure 1). Since then those stations needed to be serviced and occasionally more needed to be added to the array.

On this particular fieldwork I was in the role of a little (literally) helper – my job was mostly to service the already existing stations, but I was also shown how to install them. This involves fun cardio activity that is sure to get you out of the gym, out into the sun to around 40 degrees where you then dig ~1.5 m deep holes.

In the gravel!

Sand if you’re lucky.

Being already involved with a gym and several different cardio activities I had to pass on this brilliant opportunity and was required to service the stations (Figure 2) only.

Recorder
Figure 2: Recorder of seismic data. The big, black, enclosed, bulky thing is the battery. Plugged into the recorder are seismometer (buried in the ground) and a GPS antenna.
Courtesy of Christian Sippl.

This means I have to change the battery in the seismic recorder, to assure it keeps running. I have to collect the data from the recorder – in the form of an SD card, check them on the spot and make sure they are recorded correctly (for example, you can observe an earthquake on them, no components are acting strangely and are active and such) and then close the station, hide it – wrap it into green tarp and cover it in branches so the animals won’t chew on it (Figure 3) and lost humans wouldn’t mistake it for a water cooler. Then you move to the next station.

This whole service usually takes around ~15 mins in total. If something is wrong with the data you have to additionally change the entire recorder. Recorders weigh around ~12-15 kg (I think, at least that’s how it felt) and carrying them back and forth through thick bush is another brilliant cardio activity.

So anyways – that is what I have been doing for the two weeks of my stay in WA. A lot of driving on 4WD tracks (think bumps, holes, sand, fallen trees, salt lakes), traipsing through the bush with a heavy recorder (but I had a helper of my own! I will get to that shortly), trying to find the hidden station by means of a precise GPS, servicing the station, checking the data, potentially changing the recorder, traipsing through the bush back to the car and then some more driving.

It was mostly driving.

Cow_attack
Figure 3: What happens when animals (cows in this case) investigate you recorder – the tarp is scattered in the background and the cables are chewed through. This is why you need to properly hide the recorders and wrap them snugly in a tarp.
Courtesy of Christian Sippl

In the car with me was a member of our project partners called Umar. Umar is the greatest. There I said it – let’s move on now. He was the one who hauled this heavy recorder through the bush while I was carefully stepping and navigating in front of him with my GPS trying to find the station. Thanks to him and his sense of humor I had an excellent time and every time I found something hilarious – so did he. This resulted in a lot of laughs and giggles.

Let me share some of the stuff that happened in the remote areas of WA. I will try in chronological order, but what happened on which day exactly is a bit of a blur – I mean when camping in the bush (mostly) you wake up with the sun (around 6 a.m. if you have trees above you) and go to your swag around 8 p.m.

9 p.m. if you feel very lively.

Days soon become one long stretch.

So … if you are up for a daily account of my adventures in WA, you can find it here.

Seeing and listening to earthquakes

By Chops

The magnitude 6.5-6.8 earthquake to hit New Zealand near Wellington around a week and a half ago brought earthquakes back into the news. Rather than exploring the way the earth rattles and rolls or some other aspect of the science surrounding earthquakes, I thought it might be a great opportunity to explore earthquakes a bit differently. What I want to show off today are some different visualisations (and I use that term loosely here, as will become apparent) of earthquakes that people might find fascinating.

Image of a seismic trace on a drum seismograph. Photo from http://www.flickr.com/photos/nectarous/2883757076.

Continue reading “Seeing and listening to earthquakes”

Dynamics of the rotation of the inner core

By Chops

Some research came out of RSES last week regarding the rotation of the inner core, and how it speeds up and slows down. This research, made by Hrvoje Tkalcic and others, has got a little bit of publicity (http://rses.anu.edu.au/news-events/news/earth039s-centre-out-sync) and also was published in Nature Geoscience last week. In this post, I want to explore a bit of background on how we know what’s happening deep down inside our planet, how this particular research was performed and finally, what sort of significance this sort of work has.

Cutaway of the earth's interior
(Image from iStockphoto/Baris Simsek)

Continue reading “Dynamics of the rotation of the inner core”

Science on trial: The importance of science communication.

By Claire

By now I’m sure you’re all familiar with the case in Italy, of the seven people (six scientists and a former government official) who were convicted of manslaughter for failing to predict the L’Aquila earthquake that killed 300 people in 2009.

Worldwide, there has been outcry from the scientific community (and the community in general) over these charges. In essence, the scientists have been held accountable for failing to predict an event that can not be predicted. It appears that the scientists have become the scapegoats for this disaster, allowing the people affected by the quake to feel like justice has been served in some way.

Upon further investigation, the scientists have actually been charged for failing to accurately communicate the risk of a large earthquake that in this case, happened to eventuate and kill 300 people. The prosecutor’s case is built on the belief that the scientists gave out “inexact, incomplete and contradictory information”. Continue reading “Science on trial: The importance of science communication.”

Seismologists convicted for failing to predict earthquake

By Evan

I’ve written about this a bit in the past, but today, the news came down that six scientists have been convicted of manslaughter in Italy for failing to predict that an earthquake was imminent after a series of small tremors was a precursor to a major earthquake that killed over 300 people. I have to say I am a bit sad that this was not the top news story this morning (I guess people care more about the fall from grace of Lance Armstrong), given how much of a miscarriage of justice this is. This is from a country that has failed to prosecute a certain former prime minister, so perhaps this is not surprising.

I have to keep this short, due to being busy before heading off to New Zealand next week. I recommend reading the reaction from several leading experts on earthquake hazards on livescience.com. Pretty much all of Italy is at risk of earthquakes due to the collision of Africa into Europe. The damage seen in the L’Aquila earthquake is mostly the result of poor planning to reinforce old buildings that were not designed to withstand an earthquake. I think this quote from the livescience.com article sums it up well:

Evacuation is typically not the best response to these small swarms, according to a 2010 article published in the journal Geophysical Research Letters. That study found the likelihood of death for citizens in L’Aquila’s least-safe buildings was still only about one in 100,000 — a risk that’s better ameliorated by retrofitting dangerous buildings than evacuating entire towns for indeterminate lengths of time on the slight chance of a quake, the researchers concluded. (No charges have been brought in L’Aquila regarding building codes or standards.)

Tsunami Debris

Location of debris from the 2011 tsunami. (NOAA)

By Evan

Perhaps nothing is more sobering to an aspiring earth scientist than the results of major disasters. I remember watching the footage of the 2004 Sumatra tsunami and thinking about the responsibility we have to the public to inform about the hazards associated with natural phenomena such as earthquakes and tsunamis. The last major megathrust earthquake that produced a large tsunami before the Sumatran event was the 1964 Alaska Earthquake, which caused few fatalities due to its remote location. People were unaware of the risks in Sumatra, partially because this style of earthquake does not happen frequently, and there had been few geological investigations to determine the risk there.

In Japan, there is a long recorded history of major tsunamis. However, the sheer size of the earthquake that struck there last year was unprecedented in the past 1000 years, and barriers that were designed to handle historically large tsunamis were insufficient. As a result, there was a massive loss of life, and large amounts of debris were swept to sea. The New York Times is reporting on a vessel carrying volunteers who are documenting the debris that was swept to sea. This project is of archaeological interest, and to determine what might be coming towards the North American coast. People on Haida Gwaii on the west coast of British Columbia are already describing the beaches there as “landfills”. As a goodwill gesture, the Japanese government is offering to help pay for the cleanup, which is probably going to be an immense endeavour. Continue reading “Tsunami Debris”

Another Mars Lander Announced

by Brendan

Artist rendition of the proposed InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) Lander. InSight is based on the proven Phoenix Mars spacecraft and lander design with state-of-the-art avionics from the Mars Reconnaissance Orbiter and Gravity Recovery and Interior Laboratory missions.
Credit: JPL/NASA

Hot on the heels of the landing of the Curiosity Rover, NASA has announced plans to send another mission to Mars in 2016, and it has a very strong grounding in geophysics. The mission, known as ‘InSight’, will focus on the internal structure and thermal nature of the planet. The lander will have two main instruments, a seismometer, which will be used to measure seismic activity (Marsquakes) and a heat flow probe capable of drilling down approximately 5 metres to obtain long term measurements of heat flow.

One of the big scientific questions around Mars is whether it has any sort of plate tectonics and if not, why not? Continue reading “Another Mars Lander Announced”

Pumice island found off New Zealand

An area of floating pumice 250 nautical miles in length and 30 nautical miles wide in the South Pacific ocean. Picture: AFP / New Zealand Defence Force

(Story from News.com.au)

A giant floating island of pumice was created when a previously dormant volcano erupted amid more than 150 earthquakes over two days last month, scientists say.

The eruption of the Havre Volcano, about halfway between New Zealand and Tonga, is believed to have caused the 7500 square kilometre pumice “raft”, which was encountered by a New Zealand navy ship last week. Continue reading “Pumice island found off New Zealand”

Mount Tongariro erupts!

By Claire

Ash cloud over Ohakune.

At around midnight last night, Mount Tongariro, on the North Island of New Zealand erupted.

There are reports of ash in the area immediately surrounding the volcano, however, there have only been small amounts of lava ejected during the eruption. Scientists believe that the eruption was driven by hydrothermal processes, rather than through the build-up of lava.

Ash in the area surrounding Mount Tongariro.

The eruption comes after 3-4 weeks of volcanic unrest, including a large number of small earthquakes, leading up to the eruption. At present, there is no indication that the volcanic activity is escalating.

Follow all of the updates on the One News website.

Victoria- on the move!

A fitting slogan
Source:www.ozbargain.com.au/node/41123

By Kelly

Once again, local earthquakes are dominating the morning news. Yesterday evening  a magnitude 5.3 tremor shook southern Victoria, with the epicentre located 9.9 km beneath Gippsland along the state’s south coast.  The largest felt in almost 110 years. Geoscience Australia (GA) has reported that around 60 aftershocks have been felt in the region since and that tremors may continue for the next week. GA seismologist David Jaspen has attributed the seismic activity to the compression of the Australian continent due to the motion of plates around the Pacific region. When speaking to The Age this morning he said:

‘‘that compression leads to a building of stresses within the earth’s crust. Once that stress exceeds the strength of the rock, it will break and release energy. That’s how we generally see earthquakes occurring in Australia, a build up and then pop.”

Continue reading “Victoria- on the move!”

Seismometers in schools

Natalie Balfour looking rather pleased with her seismometer

By Kelly

In a previous post I took a peek at the career trajectory of Dr Natalie Balfour -seismologist and geosciences educator extraordinaire. Natalie is the coordinator of the “Seismometers in Schools” program, which was launched last week at Melrose High School here in Canberra. This week I’d like to follow up with more on the program itself, and why it is an incredibly effective tool to engage young scientists in the Earth Sciences. An idea that is very much in line with a certain blog I know…

“Most seismology lends itself to high school classrooms, particularly when students are learning about the physics of waves, whether it be sound or light” says Natalie. The idea of placing scientific equipment to measure seismic waves is not new, with successful programs run previously in the U.K, the U.S and in France. Students use data collected from their own seismometers to learn about wave properties such as frequency, wavelength and amplitude. However these seismometers are no toys. Display software produces seismographs allowing students to actually apply the fundamentals of maths and physics to their surrounding (and not so surrounding) environment. With the right filtering, this equipment has been able to pick up earthquakes as far as Chile, and even the recent earthquake in Italy! Continue reading “Seismometers in schools”

“Nat”ural Hazard

Map of potential sites for AuSIS instruments (red) and existing sites in ACT (yellow). The location and number of stations per state will change depending on school response and logistical considerations. Source: http://rses.anu.edu.au/highlights/view.php?article=221

By Kelly

Our Research School of Earth Sciences has a plethora of talent, tucked away in the many corridors, labs and lecture theatres. This kind of environment can foster a well-rounded graduate (or blog follower) if you actually take the time to go to the many seminars, or talk with your colleagues (or read the blog). Seismology has made it into the news, and into this blog on a number of occasions recently. So with these things in mind, I set off upstairs and was lucky enough to talk to one of our very promising and inspirational early career researchers about her current work. I say lucky as I thought I was busy, however I look positively sluggish next to Dr Natalie Balfour.

Natalie is a post-doctoral fellow in seismology with the Earth Physics group. Her position is a little different from most as she is not only a researcher – she works on the source mechanisms and rupture models for earthquakes in Indonesia – she is also coordinating the Australian Seismometers in Schools Network. And so, her position is funded through a combination of a joint linkage project with AusAid/ARC, the Australian Governments Overseas Aid Program and the Australian Research Council, and AuScope, an organisation for a national earth science infrastructure program. So how does one end up being a seismologist leading the coordination of national educational programme? Continue reading ““Nat”ural Hazard”

Looking inside the Earth

In today’s issue of Science, Robert Farla (recent RSES alumni), publishes work from his PhD that demonstrates how defects, or ‘dislocations’, in mantle rocks can slow the transmission of seismic waves. Robert’s supervisor and co-author, Professor Ian Jackson states that “this new information will help us better interpret seismological models of the Earth’s internal structure”. The abstract, Dislocation Damping and Anisotropic Wave Attenuation in the Earth’s Upper Mantle, can be viewed on the Science website or see the ANU media release.

Dr Farla, has gone on to do his post doctoral research at Yale University. This is an impressive start to what looks like a stellar career in the earth sciences.

Large earthquake but no tsunami

By Evan

As reported on the ABC, there was a massive magnitude 8.6 earthquake off the coast. This was followed a few hours later by another massive magnitude 8.2 aftershock. This earthquake happened near the same location as the 2004 Indian Ocean earthquake, though there was no major tsunami, and initial warnings were quickly called off.

Why was there no threat of tsunami? It all has to do with the way the
earth moved. The magnitude scale determines the energy released in the
earthquake (at magnitude 8.6, this earthquake was actually several times
smaller than the 2004 earthquake and the earthquake that struck Japan a
year ago). However, to produce a tsunami, there must be a vertical
displacement at the ocean floor to cause a massive wave. Yesterday’s
earthquake was caused by movement along a strike-slip fault. In this
configuration, the earth moves horizontally across the Earth’s surface.
Since there was no vertical motion on the ocean floor, there was little
threat for a devastating tsunami like the one that happened in 2004,
despite the large size of the earthquake.

For the scientific details on the earthquake, the USGS’s Earthquake
Hazards program has a detailed assessment on the earthquake (click here). Also, the Seismometers in Schools Facebook page  has information and seismometer recordings of the earthquake from schools in Australia!

Quakes unearth Australia’s underground past

Blue Lake at South Australia's Mt Gambier. Mt Gambier is one of four shield volcanoes in the Newer Volcanics province in Australia. Photo by Margaret Bee http://www.flickr.com/photos/margaretb174/

A little distraction from Kelly’s posts about Antarctica.

Recent research conducted at RSES has used some new techniques to unearth Australia’s underground past. Nick Rawlinson from the school used seismometers placed around the country to image the plate underneath South East Australia.

Getting information about the tectonic past of this area has been very difficult in the past because it is covered by large, thin cover features such as the Murray-Darling Basin. Rawlinson’s team got around this by placing seismometers in different locations around the country and then measuring ground motions from as far away as Japan, Fiji and Indonesia. It’s a pretty cool technique.

What the researchers found was pretty interesting as well. In particular, they found a pronounced anomaly extending at least 150km beneath western Victoria which points to elevated temperatures beneath an area known as the Newer Volcanics province. The region has experienced widespread eruptions until only recently and it is likely that this ‘hot-spot’ is responsible for those episodes.

If you’re interested in reading more about this innovative research, check out the ANU News Story here: http://news.anu.edu.au/?p=13391

 

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