Saturday, December 17, 2011

Questions (and Answers): Part 2

7. What do penguins eat? What other animals do you see?

At McMurdo which is close to the ocean, once the ice breaks up, it is on the ocean, there are multiple types of penguins, primarily Adele Penguins, and Wendell Seals. There are also skuas which are sort of like large seagulls. They are extremely good at stealing food from people. If you are carrying open food, they could swing in and grab it. A popular McMurdo joke is to put some bread in someone else's hood. Hilarity ensues.

Penguins eat at sea, not on land. They eat small fish and crustaceans. One of their fish hunting strategies is to dive deep under floating ice and look for fish silhouetted against the ice above them.

At the South Pole, the only animals are people. Bringing any animal onto the continent is a violation of the Antarctic Treaty.

8. What is your tent like? How do you stay warm?

We stay in the South Pole Elevated Station. It's a large complex of labs, a galley, medical facility, private (very small) berths, and the previously mentioned recreation facilities. It's warm indoors, though my work is often located outside. We stay warm with the heavy gear mentioned in a previous answer. With all of the outdoor, cold activity the body can burn (a very accurate term in this case) a lot of food calories. The galley serves up four hearty meals each day. (In addition to the usual meals there's "midrats," midnight rations, for folks working night shift.

Camping out at the South Pole requires heavy gear, or some knowledge of how to use the snow and ice to your advantage as insulation. A class is taught, both at Pole and McMurdo, known to all as "Happy Camper School" in which you learn to use the long distance (HF) radios, start the cooking stoves to melt snow, cut trenches in the snow in which to sleep, and to build snow-block construction shelters.

9. What are neutrinos and why are they important?

Neutrinos are subatomic particles. Basically the universe is made up of protons, neutrons, and electrons. Nuclear reactions are when a neutron turns to a proton or vice versa. In those reactions, scientists noted about 70 years ago that there had to be something else emitted in order for energy and momentum to be conserved (conservation laws are among the most important handles we have on the universe, e.g., no matter what you do, the total amount of energy, charge, and other properties stay the same) there had to be another particle, not seen at the time, coming out of the reaction. That's the neutrino.

Since that time the neutrino has been observed, it reacts very rarely, meaning that detectors need to be large in order to have a good chance of seeing the particle. That makes it hard to do neutrino astronomy, but it also means that neutrinos get to us from anywhere in the universe. Light or other particles only reach us from relatively close by, farther away and the universe turns black, turns opaque, to the particles. But not to neutrinos, so we can look farther, and at higher energies at the whole universe with neutrinos. That's why they're important.

10. How many people are at the South Pole? What do they all do?

It's summertime now, the warmest time of the year, there are between 200 and 250 people at the US South Pole Station. There are flights in and out every few days and the population changes depending on what projects are ongoing. For the Amundsen Centennial, there were almost 100 visitors to the South Pole. There's no other permanent base here. During the winter, about 50 people stay at the South Pole Station. After the last flight in February those 50 people are stuck here until October. Six months of that in the dark! Not something I'd opt to do.

At McMurdo, during the summer there are up to 1100-1200 people there, and in the winter about 200 folks.

There are all sorts of work going on both at Pole and McMurdo, people work on the fuel systems (fuelies), haul, sort and manage cargo, cook the food, clean the dishes ("dining assistants"), drive the vehicles, staff the fire house and medical, do science, keep the heating working, shovel snow, etc. The vast majority of people in the Antarctic Program are in support roles, keeping the science going.

11. What are the differences between Icecube and ARA?

IceCube is fully built, completed last Antarctic Summer, uses the light emitted from neutrino interactions in the very clear, cold ice to observe the neutrinos. The science goals are focused on neutrinos from supernovae, from active galactic nuclei, and cosmic ray anisotropy. ARA is a new project, we're just starting construction, and will take advantage of the radio (rather than optical) emission from neutrino-induced showers (cascades) in the radio-transparent cold ice. The science focus is at higher energies than IceCube and looking at the close connection between very high energy cosmic rays and the neutrinos.

IceCube is an instrumented kilometer-cubed of ice with modules spaced 17m (60ft) apart vertically and strings spaced 125m (400ft) apart. ARA will cover an area of over 100 square kilometers and observe interactions down to the bottom of the 3000m (10,000ft) thick ice sheet.

12. What other projects and experiments are at the Pole?

There is a large microwave band telescope (SPT, South Pole Telescope) here that takes advantage of the lack of water vapor in the atmosphere above the Pole. Other telescopes at the Pole are a couple of different efforts to look at the Cosmic Microwave Background (CMB); experiments called SPUD, BICEP, and VIPER. In different fields, there's a clean air lab that looks at some of the most pristine air on earth. (You can visit them and get a little jar of the cleanest air anywhere that you could use as a gift.) There's also a seismic sensor (SPRESSO) a few miles from the station, magnetometers monitoring the Earth's field, neutron monitors looking at charged particles from the Sun and the changing solar cycles, aurora cameras (for the winter dark sky), a meteorological observatory, and ice-coring and meteorite-hunting expeditions out in the field away from Pole.

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