Tag Archives: Heard Island Expedition

Glaciers and City Buses

Central and southern portion of Heard Island, including Gotley glacier.  Image credit: NASA ISS.
Central and southern portion of Heard Island, including Gotley glacier. Image credit: NASA ISS

Heard Island is covered by 41 glaciers.[1] Some of these glaciers, such as Stephenson Glacier, are retreating rapidly, while others, like Gotley glacier in the southwest, have remained steady since 1947 when detailed surveys began.

The glaciers on Heard Island, like glaciers everywhere, act much like a conveyor belt, a giant river of ice. Snow (and rain) falling near the top solidifies into ice and flows downhill, until either the ice melts and flows away as a stream, or the ice meets the ocean and calves (breaks away).

Unlike the conveyor belt analogy, the snow does not only fall at the very head. Indeed, at times, the whole glacier can receive snow, or could be melting at the surface. On average, though, the snow accumulates in the eponymous accumulation region, and melts in the depletion region.

Perhaps a better analogy for a glacier is not a conveyor belt, but a city bus which runs into, and through, a city. Toward the beginning of the route, people board the bus, but very few leave. In the middle of the city, some people come and others go. Finally, as the bus leaves the city toward the surrounding area, more people leave than get on, and after reaching the end of the route, the bus is empty of passengers.

To really get a grasp of how glaciers work, you might want to try this Java-based simulation (helpful activity guide). One aspect of glaciers that becomes apparent in the simulation is that the surface of a glacier moves more rapidly than its base. There’s a tool to let you drill a virtual hole in the ice, then watch as the hole gets stretched out as the glacier flows downhill.

Now that you’ve spent a while playing around with the simulation—I certainly have—let’s take a look at the glaciers of Heard Island.

As I mentioned before, some glaciers are retreating, while others are relatively unchanged. Several factors influence the size of glaciers: precipitation amount, freezing level (of the atmosphere) [generally related to sea level surface temperature], relative humidity, albedo (reflectivity), and the thickness of rocky debris cover.

Precipitation and the freezing level are fairly straightforward factors: more snow and cooler temperatures yield larger glaciers. But there are complications! In a windy environment, such as that of Heard Island, snow doesn’t just pile up evenly as it falls; it drifts. Snow that falls in one place may end up being picked up by the wind and deposited somewhere downwind. This effectively adds precipitation to downwind areas, and removes it from upwind areas.

Relative humidity is important to glacier size, because even cold, dry air can cause snow and ice to sublimate—turning directly from solid to gas. In places like the McMurdo Dry Valleys in Antarctica, this effect keeps the valleys from filling with snow and ice. On Heard Island, a shift in the wind, or a more steady wind direction, can cause different areas to be affected by these dry winds, or to be affected more than in years past.

Here are some of Ruddell’s comments on the matter of why some glaciers are retreating and others do not:[1]

The accumulation, distribution and snowline elevation on many Heard Island glaciers appears to be influenced strongly by the re-distribution of snow by the wind. The prevailing wind direction is westerly and there is less likely to be a re-distribution of snow to low elevations on the westerly facing glaciers… Further, the re-distribution of snow by wind on west-facing glaciers is likely to be impeded not only by wind speed and direction but by severe crevassing (e.g., Gotley Glacier).

When the Heard Island expedition arrives this (austral) November, the glaciers can be observed from close range, rather than by satellite. An additional topic of interest is documenting the advance of vegetation toward recently de-glaciated areas.

During the 1947-2000 period, the glaciers on Heard Island showed an overall reduction in area of 12%.[1] The trend has been toward retreat, and with temperatures increasing about 0.8 °C since 1947, the glacier areal coverage in 2015 is almost certain to be lower still.

***

[1] Ruddell, A. “An inventory of present glaciers on Heard Island and their historical variation”, in Heard Island: Southern Ocean Sentinel (Eds K. Green and E. Woehler) Surrey Beatey & Sons, 2006, p. 28-51.

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T -7 Months and Counting

Fair weather at Atlas Cove and on the Laurens Peninsula, Heard Island, taken April 10, 2015.  Nominal resolution is 250 m/pixel.  Image credit: NASA Terra/MODIS.
Fair weather at Atlas Cove and on the Laurens Peninsula, Heard Island, taken April 10, 2015. Nominal resolution is 250 m/pixel. Image credit: NASA Terra/MODIS.

We are now just under seven months from departure from Fremantle, Australia, to Heard Island. Preparations continue for the expedition; seven months may seem like a long time, but many projects need to be accomplished by then.

With plans for operations coming together nicely, there is a new focus on selecting, acquiring, and testing the equipment and supplies to be used on the expedition. Here are a few examples of choices which will need to be made:

  • What kind of shelter will we use?
  • What will we do to keep the shelter from blowing away?
  • How will we keep the shelter warm?
  • On what will people sleep?
  • What food will be brought on the expedition?
  • What kitchen equipment do we bring?
  • How will we network the computers, including shelters 200–300 m away?

Of course, as we make these choices, we are also considering what sort of backup plans we have. This expedition, like any other, is a delicate balance between redundancy, robustness, and minimalism (weight, cost, and labor).

One factor in choosing gear which is often overlooked in temperate climes is that of its poor-weather field-usability. With the precipitation, high winds (blowing snow, rain, and volcanic sand and dust), and cold temperatures, small pieces or anything requiring manual dexterity should be avoided. Choosing glove-appropriate tools and equipment can make the difference between a good day of efficient field work, and a very uncomfortable, miserable day in the cold, wet wind. Without glove-appropriate gear, the gloves have to come off, which in turn drastically reduces their [the gloves’] effectiveness.

Fortunately, on this expedition we will not have to deal with the temperatures found in the coldest regions of the world. In those extremely cold regions, eating utensils (at least fork and spoon) must not be made from metal—they will act as a heat sink and conduct heat away from your mouth very efficiently. I may bring wooden utensils just in case.

Procuring the gear we need presents its own logistical problems. The expedition leader and many of the support team are based in the US, but anything bought in the US has to be shipped to Australia. Buying things in Australia saves shipping, but larger items can’t be tested by the US team. There are further differences in things like electrical power distribution; generators will need to match the plugs and voltage required by the equipment, and the VK0EK amateur radio team need to be confident that the electrical devices we bring won’t interfere with their operations.

For my proposed research project, I have been wrestling with a the questions I posed in my previous post on expedition preparation. Some of the questions have been resolved. Not all of my lines of inquiry were successful. A number of locations I thought would be good to sample have, upon further reflection and study, turned out to be unlikely to yield results which would add meaningful data to my research. Further discussion with other scientists is planned, and I expect will help further clarify a plan of action—though it may be to scrap the project altogether and pursue a related research question.

This weekend, I finally got my hands on a book I have been looking forward to reading: Heard Island: Southern Ocean Sentinel. I took a brief glance through it, and there is a lot of good information there. Although I had planned to write today about glaciers, specifically the glaciers on Heard Island, I have deferred that for the time being so I can read more before writing that post. Maybe next time!

T -8.5 Months and Counting

A cold winter day in Minnesota.  The weather makes staying inside working on Heard Island expedition planning easier.  Image credit: Bill Mitchell.
A cold winter day in Minnesota. The weather makes staying inside working on Heard Island expedition planning easier. Image credit: Bill Mitchell.

We are more than eight months away from departing Fremantle bound for Heard Island, but there is a lot happening behind the scenes. Here is a sampling of what I have been up to for the last week or so.

I have been appointed the on-island IT czar for the expedition. Making sure the expedition computers run, and that the network interfaces properly to the satellite equipment for phone/data links to the rest of the world, fall under my responsibilities. Despite the satellite phones, we have to plan for having no or nearly no data connection with the outside world. Any software we need has to be installed before we go. Manuals need to be saved locally, because the standard “just ask Google” method of tech support will not work.

The amateur radio operations (VK0EK) will need some fairly complicated software and networking. Data needs to be saved redundantly, and shared across computers in near-real-time. We also intend to have custom software sending some of that data back to the outside world. So this week, I have been installing software on a laptop I will use for testing everything. I met with the software developer of our custom software via Skype to get an idea of how it works and what the trouble spots may be. Documentation is important, so I am taking notes on how the computer is being set up. Once it’s working, we may need to replicate it on another 10 computers.

Some of the programs I am installing are new to me, so I have also been learning how to use them. This weekend, I will have a chance to test my understanding of them more thoroughly. There are several different programs which all need to function in concert with each other, and we need for things to be very reliable.

One consideration that goes into the decisions on technology for Heard Island is that with the high winds, volcanic ash and dust tends to get picked up and blown about absolutely everywhere. This is not only a problem in terms of keeping the insides of the shelters clean, but can also do quite a number on moving parts such as motors, fans, and hard drives. In creating our technology plan, we need to plan for multiple hardware failures, and devise a resilient solution. With guidance from the many experienced team members (both on- and off-island folks), I think we will do well in creating a computer system to support the expedition. It looks to be coming together well so far.

In addition to the IT work, I have been working on my plans for scientific work on the island (mini-spoiler: I’m not ready to disclose details of the plans; the following will be abstract). Scientific activities this week have included trading a few emails with a potential collaborator, continuing to track down as much Heard Island research in the peer-reviewed literature as possible, and even reading some of that literature.

Here are some of the questions I’m wrestling with:

  • Where are the best places to sample?
  • What equipment will best balance scientific value of samples with cost, size, and the number of personnel needed to operate it?
  • What are the likely difficulties I will encounter?
  • What am I likely to find?
  • In what ways will the simple model I have in my head differ from the more complicated reality on Heard Island?
  • How close are the sampling locations to the base camp?
  • Would any of the work I intend to do be replicating what has already been done?
  • Are there ways to make my work help guide interpretation of previous research or other research being done on this expedition?
  • How much time is needed for carrying out the scientific work, and in what size blocks?

Many of these questions are interconnected. Sampling locations need to be close enough to the base camps that I can reach them easily, no multi-day hiking trips will work for me, and water transportation is unreliable due to the weather. They need to be in a location which has the kind of rocks/other stuff I want to study. I need to have the tools to sample or measure well, but they can’t be so large or bulky that they require a 4-person team to haul and operate. All of the equipment has to be landed by zodiac, after all. The overall budget for my research is not very large, so equipment choice will need to bear that in mind.

But the biggest thing is figuring out what to expect. Will the sample of rock I get be a few years old? A few decades? Tens of thousands of years old? More? Will vegetation, ice, or fauna block access to the sampling location? If I were to sample sedimentary rocks, would processes such as mass wasting (e.g. landslides), glacial movement, or animal burrowing have disrupted the even bedding of my ideal sediment? The equipment which is best suited for the work, and the amount of interest from collaborators, could vary greatly depending on what the expected results are.

So in the mean time, I read all that I can, talk with other scientists, and prepare a plan of action. Decisions need to be made soon, because equipment needs to be acquired either in Australia by some of the local team there, or here in the US in time for the Bay Area team to load it into the container to be shipped in the early (northern hemisphere) fall.

Back to work!

Topographic Map(s) of Heard Island, and a Big Landslide

Heard Island Map, 1985.  Image credit: excerpt from the Division of National Mapping.
Heard Island Map, 1985. Image credit: excerpt from the Division of National Mapping.

A few days ago, I posted about topographic maps, including a discussion of how a small army of small surveyors made one of my local park. At Heard Island, surveying isn’t a walk in the park.

Many maps have been made of Heard Island, showing the topography and general geographic features of the island, and sometimes including the locations of major macrofauna (penguins, elephant seals, etc.).[1] An excerpt I made from one produced in 1985 is shown above. Although there are more recent maps available, including maps with higher topographic resolution, this one is more visually illustrative of the landforms.

Maps of Heard Island are difficult to produce, in part because there is a dearth of high-resolution, high-quality data. In most parts of the developed world, detailed topographic maps are made not through boots-on-the-ground surveying but by airborne LiDAR. For instance, aerial imagery and LiDAR provided very useful data for understanding the Oso landslide in Washington state. However, aerial flights over Heard Island are much less frequent, and mapping efforts there come without the obvious benefits to the local populace.

LiDAR map near the Oso landslide (red region at right), and a larger landslide complex (red region at center).  Image credit: Dan McShane.
LiDAR map near the Oso landslide (red region at right), and a larger landslide complex (red region at center). Image credit: Dan McShane.

Surveying the whole island by foot at high detail is untenable, because the area is quite large, the terrain difficult, and the weather inclement, even in the summer. However, portions have been mapped by hand (and theodolite).

But perhaps the biggest challenge Heard Island presents to cartographers is the rapidity of its changes. Volcanic eruptions can add new land to the island, or make parts higher. Glaciers can carve out the rocks and leave them as till, sometimes in the ocean, sometimes in the lagoons, and sometimes as moraines on the land. Not only can the glaciers carve out the rocks, but as less snow accumulates on the glaciers than is lost to melting, the glaciers will retreat. This opens up new land which before had been covered in ice. Stephenson Glacier, on the southeast corner of Heard Island, has retreated significantly in the last 60-70 years, revealing a great deal of new terrain.

Steep slopes and the very wet environment (lots of snow and rain) lead to very high rates of erosion. Outwash channels from the glaciers can carve into the rock and transport sediment into lagoons and near-shore areas.

Finally, there’s another agent of change: landslides. Take a look at the LiDAR image above, showing the landslide region. Now take a look at the southwest portion of the Heard Island shown at the top of the post. The curving crest along the north and east sides of the volcano, as well as the ridge extending to the south-southwest are interpreted to be the boundary (technical term: scarp) of a debris avalanche (a landslide-like process).[2]

Taken as a whole, these processes change the landscape significantly on a decade-to-century timescale, if not even more rapidly. This is why making maps and keeping them current is so valuable: it give us a way to see how the landscape is changing over time. Perhaps the upcoming Heard Island Expedition will do some mapping and be able to provide updates which reflect the latest changes at Heard Island.

[1] https://www1.data.antarctica.gov.au/aadc/mapcat/list_view.cfm?list_id=1, accessed Feb. 6, 2015. Free registration required for map download.

[2] Quilty, P. G. & Wheller, G. 2000; Heard Island and The McDonald Islands: a Window into the Kerguelen Plateau. Papers and Proceedings of the Royal Society of Tasmania. 133 (2), 1–12.

On an Island Far Away…

World map.  Image credit: NASA
World map. Image credit: NASA. Click for full size.

In order to better understand the project, and what I will be doing on Heard Island, it is important to know things about the island itself. Perhaps the easiest thing to talk about is where the island is.

Here’s the same world map as above, but now with additional annotation. Shown in partial transparency is the western hemisphere antipodes (opposite side of the world). A red arrow points to Heard Island, and a red circle in Saskatchewan marks Heard Island’s (approximate) antipode.

Red arrow marks location of Heard Island; red circle marks approximate location of Heard Island antipode.
Click for full size. Red arrow marks location of Heard Island; red circle marks approximate location of Heard Island antipode. Adapted from NASA.

As you can see, Heard Island (technically Heard Island and McDonald Islands) is far away from other land, and about as far from Minnesota as one can go without being in space.* There are no airports on the island. Only by sea (or helicopter for the final mile) can we reach the island. For our expedition, there will be no helicopter.

To reach the island, our team will board the Akademik Shokalskiy in Fremantle, Australia (southwest corner, near Perth) RV Braveheart in Cape Town, South Africa. We will then sail southwest southeast through the Roaring Forties and into the Furious Fifties, and about ten days after departure (weather permitting, and in that part of the world it is often inclement) we will arrive.

Heard Island is of a modest size, 20-30 km across (13-20 miles). In the center is a 9000-foot tall volcano, Big Ben, which I will elaborate on in a further post. Mantling Big Ben and flowing down to the sea are glaciers, which cover the majority of the island. In many places, the ice forms sheer cliffs where it enters the sea, making landing on the island difficult.

There is no permanent human settlement on Heard Island. An early research party stayed for fifteen months during 1947-1948 [2], and the most recent winter expedition was in 1992. It is an Australian territory, and home to one of Australia’s two active volcanoes—the other being the smaller, nearby McDonald Island.

Because Heard Island is so remote and has such active surface geology (volcano, glaciers, streams, high wind) and has no permanent inhabitants or introduced species, it has been designated a UNESCO World Heritage Site.[2]** These conditions make the island an excellent natural laboratory to study all sorts of phenomena from climate change to glaciology to biology.*** I’ll have lots more on all that coming up in future posts!

[1] Arthur Scholes, Fourteen Men, E. P. Dutton, 1952.
[2] http://whc.unesco.org/en/list/577 UNESCO organization. Retrieved January 8, 2015.

* Space is much closer to Minneapolis than Heard Island, or even South Dakota.
** For more on this general topic, the Wikipedia page on the Geography of Heard Island and McDonald Islands is informative.
*** While it is unlike me to paraphrase J. D. Salinger’s Holden Caulfield (from Catcher in the Rye), if you thought it was a somewhat tricky question figuring out where ducks go in the winter, think about where these penguins go in the winter. They do migrate away from Heard Island.[1]

Update 5/14/2015: Vessel and port of departure have changed. More info here (my blog) and here (official).

Welcome!

Welcome to The Inquisitive Rockhopper!

Named after rockhopper penguins, which are naturally inquisitive, the title plays on the author’s affinity to hop about on rocky outcrops admiring the geology.

This draw to neat rocks has extended so far that I am going on the Heard Island Expedition to (you guessed it!) Heard Island in November and December of 2015 March and April, 2016. While there I will do some science—perhaps assisting with a population survey of rockhopper penguins and other birds—as well as lots of ham radio as VK0EK.

On this blog I intend to cover a review of the scientific knowledge so far acquired on or about Heard Island, what I hope to accomplish while I’m there, and what some of the challenges are associated with this expedition. I am also on Twitter as @i_rockhopper.

Update 5/13/2015: Expedition has been rescheduled for March/April, 2016. More info here (my blog) and here (official).