Expedition Search

The research focuses on the interactions between plants and their pollinators, which are animals that aid in plant reproduction through transporting pollen. The aim is to understand how changes in temperature and precipitation may influence plant-pollinator interactions and plant reproduction. Temperature and water availability may alter the timing of flowering and floral traits that attract pollinators, such as nectar volume and flower size. In addition, temperature may alter what pollinator species visit flowers and how often they visit. The combination of these effects on plants and pollinators may influence plant reproduction, measured as the number of fruits and seeds a plant produces. The researchers hope to relate changes in the abiotic environment to floral attractive traits, pollinator visitation, and ultimately the reproductive success of plants. Three focal plant species, blueberry, harebell, and dwarf fireweed are used because they are common in the area and flower at different times of the season.

This work can have important pan-Arctic and global implications. The majority of flowering plants in nature and one third of our crop plants depend on pollinators to produce fruits and seeds. As temperatures rise in the Arctic, successful adaptation and range expansion of many plants, including plants migrating into the Arctic, will depend on pollinators. This study will help us determine which mechanisms may most strongly drive changes in plant-pollinator interactions and plant reproduction.

In the Arctic, bright summers and dark winters are a fact of life and can lead humans to rely on clocks and routines to tell them when to eat or sleep, but how do animals function under these conditions? Circadian rhythms refer to the "internal body clock" that regulates the approximately 24-hour cycle of biological processes in animals and plants. Rhythms in body temperature, brain wave activity, hormone production, and other biological activities are linked to this 24-hour cycle. The Earth's light-dark cycle provides the strongest influence on circadian rhythms and is thought to be the primary driver for the emergence and evolution of internal clocks. In the Polar Regions, however, photoperiod exhibits extreme annual variation because of near 24 hour sunlight in the summer and 24 hour darkness in the winter. In the absence of a well-defined light-dark cycle, some arctic residents lose their daily organization of behavior and physiology, and it is thought that the molecular clockwork that drives circadian rhythms may be weak or absent in arctic vertebrates.

The research team has recently found that the arctic ground squirrel displays daily rhythms of body temperature throughout the arctic summer, in the absence of a light-dark cycle. The current study will investigate the circadian rhythms in arctic ground squirrels during the continuous daylight present during the active summer season and continuous dark of the 6-8 months of hibernation spent sequestered in a burrow. The team wants to understand why arctic ground squirrels, unlike other arctic vertebrates, appear to maintain 24-hour rhythms during the active season. They hypothesize that the persistence of circadian rhythmicity allows ground squirrels to reduce energy expenditure by anticipating predictable changes in its immediate surroundings. They are testing their hypothesis by experimentally phase-shifting free-living ground squirrels to be active at 'night' and estimating their subsequent rates of energy expenditure.

Operation IceBridge, a six-year NASA mission, is the largest airborne survey of Earth's polar ice ever conducted. IceBridge uses a highly specialized fleet of research aircraft and the most sophisticated science instruments ever assembled to characterize yearly changes in thickness of sea ice, glaciers, and ice sheets in the Arctic and Antarctic. The research team experiences first-hand the excitement of flying a large research aircraft over the Greenland Ice Sheet. While in the air they record data on the thickness, depth and movement of ice features, resulting in an unprecedented three-dimensional view of ice sheets, ice shelves, and sea ice.

Operation IceBridge began in 2009 to bridge the gap in data collection after NASA's ICESat satellite stopped functioning and when the ICESat-2 satellite becomes operational in 2016, making IceBridge critical for ensuring a continuous series of observations of polar ice. IceBridge flies over the Arctic and Antarctic every year—in the Arctic from March to May and the Antarctic in October and November. By comparing the year-to-year readings of ice thickness and movement both on land and on the sea, scientists can look at the behavior of the rapidly changing features of the polar ice and learn more about the trends that could affect sea-level rise and climate around the globe. More information about IceBridge can be found at the NASA project website.

The students and teachers will spend five days on King George Island, learning about the scientific research conducted in and around Escudero base. The program could include visits to Elefanteras Beach to study seals and penguins, Collins Glacier where mosses, grasses, and algae may be found in the ice, and Bellingshausen Dome to discuss glaciological studies. There will also be the opportunity to stop at other Chilean stations as well as other countries stations located on King George Island.

¿Qué están haciendo?

Los estudiantes y maestros pasarán cinco días en la Isla Rey Jorge aprendiendo sobre los proyectos de investigación científica que se llevan a cabo cerca de la base Escudero. El programa podría incluir visitas a la Playa Elefanteras para estudiar elefantes marinos y pingüinos; al Galciar Collins donde crecen musgos, pastos y algas en el hielo; o al domo Bellingshausen para aprender sobre estudios en glaciología. También tendrán la oportunidad de visitar otras estaciones chilenas de investigación, así como las estaciones científicas de otros paises que también están localizadas en la Isla Rey Jorge.

This project investigated the marine system of the Totten Glacier and Moscow University Ice Shelf, East Antarctica which has shown a recent increase in ice loss. This system is of critical importance because it drains one-eighth of the East Antarctic Ice Sheet and contains a volume equivalent to nearly 7 meters of potential sea level rise, greater than the entire West Antarctic Ice Sheet. This rarely explored region is the single largest, least understood, and potentially unstable marine glacial system in the world. Despite intense scrutiny of marine-based systems in the West Antarctic Ice Sheet, little is known about the Totten Glacier system.

This project conducted a ship-based marine geologic and geophysical survey of the region, combined with a physical oceanographic study. The results have added to our understanding of the oceanographic and glacial system and its potentially sensitive response to environmental change. This endeavor complemented studies of other Antarctic ice shelves, oceanographic studies near the Antarctic Peninsula, and ongoing development of ice sheet and other ocean models.

How do you find something that isn't directly visible? That's the challenge faced by the team that developed the IceCube neutrino detector under the ice at the South Pole. Just as X-rays allow us to see bone fractures and MRIs help doctors find damage to soft tissue, neutrinos will reveal new information about the Universe that can't be seen directly. The in-ice particle detector at the South Pole records the interactions of neutrinos which are nearly massless sub-atomic messenger particles. Neutrinos are incredibly common (about 100 trillion pass through your body as you read this) subatomic particles that have no electric charge and almost no mass. They are created by radioactive decay and nuclear reactions, such as those in the Sun and other stars. Neutrinos rarely react with other particles; in fact, most of them pass through objects (like the earth) without any interaction. This makes them ideal for carrying information from distant parts of the universe, but it also makes them very hard to detect.

All neutrino detectors rely on observing the extremely rare instances when a neutrino does interact with a proton or neutron. This transforms the neutrino into a charged particle of the same type as the neutrino flavor (electron, muon, or tau). Muons are charged particles that can travel for 5-10 miles (8-16 kilometres) through matter depending on their energy, and generate detectable light in translucent media.

IceCube is made up of thousands of sensitive light detectors embedded in a cubic kilometre of ice between 1450 m and 2450 m below surface. The sensors are deployed on strings in the ice holes that were made using a hot water drill. IceCube detects about 300,000 neutrinos a year, and has a projected life time of two decades. The data collected will be used to make a "neutrino map" of the universe and to learn more about astronomical phenomena, like gamma ray bursts, black holes, exploding stars, and other aspects of nuclear and particle physics. However, the true potential of IceCube is discovery; the opening of each new astronomical window leads to unexpected discoveries.

It's hard to imagine that anything could live in the cold, dry soils of Antarctica. Early investigations of the soil bacterial communities of the McMurdo Dry Valley found only a handful of bacteria, leading to the conclusion that these soils were essentially sterile. The idea that microorganisms can grow at all in the very dry soils of the McMurdo Dry Valleys seems astounding but the recent use of advanced molecular biology techniques to investigate soil biodiversity has revealed a surprising bacterial richness in the area.

The goal of this project was to identify active members of the McMurdo Dry Valley soil microbial community and determine their ecological role. Little is known about bacterial populations in the Dry Valley soils, but until it is understood which populations are active and what they do, it is impossible to understand the ecological role that bacteria play in ecosystem function.

Antarctica plays a central role in global tectonic evolution. Competing theories have been put forward to explain the formation of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB), primarily due to a lack of information on the crustal thickness and seismic velocity of these areas. The research team has attempted to resolve how the TAMs and WSB originated and how their formation relates to Antarctica's geologic history. Since most of Antarctica is covered by large ice sheets, direct geologic observations could not be made; therefore, "remote sensing" methods like seismology had to be used to determine details about the earth structure.

The goal of this project, funded by the National Science Foundation, was to broaden our knowledge of geology in this region with a new seismic array; the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that helped fill a major gap in seismic coverage. Data from TAMNNET was be combined with that from previous and ongoing seismic initiatives and was analyzed to generate an image of the seismic structure beneath the TAMs and the WSB.

While in the field, the team spent most of their time servicing the seismic stations that compose the new TAMNNET array. This included loading equipment onto small airplanes, flying to remote field locations, uncovering the deployed equipment, and checking for any maintenance issues. The first batch of data from the network was also retrieved during this time.

Coastal ecosystems of the Arctic receive extraordinarily large quantities of terrestrial organic matter through river discharge and shoreline erosion. The fate of this organic matter is of both local and global interest as it relates to biological production in the coastal ocean as well as the global biogeochemical cycle. Terrestrial organic matter has the potential to provide an important source of carbon and energy to support and maintain organisms and food webs in coastal waters during much of the year. The goal of this research was to determine how seasonally distinct terrestrial inputs of water and organic matter influence microbial and animal communities in coastal waters of the Alaskan Beaufort Sea.

Research sites ranged from lagoons to open coastal systems and each site was used to examine linkages between biological communities and organic matter inputs from land. Measurements of water and sediment chemistry, and benthic and water column community characteristics were used to evaluate the importance of terrestrial inputs under different hydrologic/hydrographic conditions.

Understanding the fate of terrestrial carbon in arctic coastal waters is especially important now as the arctic system enters a period of rapid climatic change. Changes in terrestrial organic matter export could influence the productivity and roles of organisms in arctic coastal waters. Such shifts have consequences for local human populations that fish and hunt for subsistence and for the broad scientific community interested in land-sea coupling.

In addition to their research, the team continued their successful K-12 outreach program entitled "Climate Change in the Arctic: An Interactive Program Linking Scientists with K-12 Students". This included the continuation of a summer field science program for native Kaktovik K-12 students. The Village Council has continued to express keen enthusiasm to involve school children in hands-on science activities that support learning of key science concepts.

In addition, PolarTREC teacher Jill Smith learned about the cultural importance of the annual bowhead whale hunt that began while she was in residence at Kaktovik. She had the opportunity to share this information through real-time video connections with her students in her home classrooms in Texas, enabling students from Texas to have direct dialogues with students in rural Alaska.

This project sought to understand the formation of drumlins, some of the most mysterious and poorly understood of glacial landforms. Drumlins are elongated, aligned hills that form hidden from view beneath glaciers. The first modern drumlin field has recently been exposed by the retreat of Múlajökul. Previously this kind of landform could be studied only by focusing on drumlin fields that formed long ago in the Pleistocene, so this study provided a unique opportunity to understand drumlin formation better.

The research team collected intact till (rocks and finely ground material picked up by a glacier, and deposited as sediment along its path) samples from the drumlins and the surrounding area. The samples were taken back to Iowa State University and the University of Wisconsin Milwaukee and subjected to geotechnical tests and magnetic fabric analyses. This testing determined the former distribution of stresses on the till and patterns of subglacial till deformation that were likely central to the formation of the drumlins. In addition to helping determine the internal structure of drumlins and how drumlins form, this research will shed light on the distribution of basal drag beneath glaciers—an important and poorly understood factor in their dynamics.