Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

PALAOA, worldwide unique underwater acoustic observatory, celebrates its fifth anniversary

14.01.2011
Live sounds of seals and whales from Antarctica

Listen live on the Internet to what’s going on under the Antarctic sea-ice. The Alfred Wegener Institute’s PALAOA underwater acoustic observatory has made this possible for over five years.

The acoustic observatory has been continuously recording sounds under the ice near Neumayer Station since 28 December 2005. It provides the world’s longest time series of civilian acoustic measurements, enabling researchers to study the presence and behaviour of animals under the Antarctic ice. This has led to many new findings on the distribution and behaviour of several whale and seal species.

Recording the underwater calls of marine mammals is one of the most promising methods to study distribution and seasonal migration of these animals in the ice-covered Antarctic. Visual sightings of marine mammals in Antarctic waters are rare since human access is limited and animals only occasionally surface to breathe. Acoustic recordings, on the other hand, can be made year round. By means of the PALAOA observatory, ocean acoustics experts from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association have discovered that leopard and Ross seals populate Antarctic waters near Neumayer Station III.

For many sounds it is now known by what species they are produced and, in some cases, in what type of behavioural context they are produced. Such acoustic data can be used to derive information on the timing of mating and reproduction of the various species. Acoustic behaviour of leopard and Ross seals, for instance, shows that both species also reproduce in coastal Antarctic waters. Previously this was only known for Weddell and crabeater seals.

Inter-annual comparisons of acoustic data indicate that the timing of reproduction is linked to the availability of certain types of ice on which the animals give birth to their young. “Some seal species actually are acoustically present in the PALAOA recordings in the same calendar week every year,” Dr. Ilse van Opzeeland describes the surprisingly exact timing of the animals. Researchers at the Alfred Wegener Institute were astonished to hear humpback whales on the edge of the Antarctic continent, even in austral winter. The observatory has also recorded calls of Antarctic blue whales, thereby refuting the existing presumption that the largest animals living on Earth avoid ice-covered waters.

Even 50 years after the end of commercial whaling in Antarctica very little is known about the long-term population development of these nearly exterminated giant whales. Traditional counts based on sightings often record only a few of these marine mammals during an expedition over several months. The PALAOA data, on the other hand, contain blue whale vocalisation almost every day because the calls of these animals have a very great range extending to several hundred kilometres. Such information is extremely important to gain a general understanding of the behaviour, size and recovery of the stocks of large whales, which are still endangered in a variety of ways.

The loudest sounds recorded by PALAOA stem from iceberg collisions. About once a year giants the size of Berlin bump into each other or into the edge of the ice shelf. These create quite a racket in the Bremerhaven offices of the ocean acoustics specialists, whose daily work is accompanied by the live sounds from the Antarctic. Aside from their usefulness for research, the extraordinary sounds from the Antarctic Ocean have also found their way into radio and television as well as into the works of musicians, composers and creative artists. In 2010 more than three million visitors saw and heard the walk-on sculpture and sound installation “Iceberg PALAOA” floating on the Ruhr River in Essen – it represented one of the highlights of the European Capital of Culture “RUHR2010”.

Background:
PALAOA stands for PerenniAL Acoustic Observatory in the Antarctic Ocean and also means “whale“ in the ancient Hawaiian language. It is the only hydroacoustic observatory in the immediate vicinity of the Antarctic continent, or more exactly on the Ekström Ice Shelf in the eastern Weddell Sea at 70°31’S 8°13’W. In December 2005, several hydrophones and sensors were positioned under the ice through holes drilled through the floating, 100 meter thick ice shelf around 25 kilometres north of the German Neumayer Station. Continuous recording of the underwater sounds for a period of several years enables unique acoustic observation of the underwater animal world. The recordings are made year-round and enable comparisons of the acoustic environment between years. In terms of energy, PALAOA is self-sufficient: solar cells and a wind generator supply the observatory with renewable energy 90% of the time. During the months of darkness in the Antarctic winter and at temperatures down to 50°C, a fuel cell driven with methanol springs into action on windless days to guarantee continuous operation. The acoustic observatory has recorded more than 30,000 hours (6 terabytes) of data in the past five years and registers a broad range of frequencies. This means PALAOA detects the low-frequency sounds of blue whales as well as the high-frequency clicks produced by orcas, that function as a biological echo sounder for orientation. Alongside acoustic data, oceanographic data, the movement of the ice shelf and sea ice and local shipping traffic are recorded in order to study their influence on the behaviour of the large marine mammals. Researchers hope to collect data for several more years until the ice shelf on which PALAOA is located breaks off and moves around the southern continent as a drifting iceberg.
You will find examples of sounds and valuable information on PALAOA on the Internet at: http://www.awi.de/de/aktuelles_und_presse/hintergrund/palaoa_wie_klingt_

das_suedpolarmeer/

The recordings are transmitted via a WLAN and satellite link directly to Bremerhaven and can be heard as a livestream here: http://www.awi.de/PALAOA

The Alfred Wegener Institute conducts research in the Arctic, Antarctic and oceans of the high and mid latitudes. It coordinates polar research in Germany and provides major infrastructure to the international scientific community, such as the research icebreaker Polarstern and stations in the Arctic and Antarctica. The Alfred Wegener Institute is one of the sixteen research centres of the Helmholtz Association, the largest scientific organisation in Germany.

Margarete Pauls | idw
Further information:
http://www.awi.de

More articles from Earth Sciences:

nachricht GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center

nachricht Cyclic change within magma reservoirs significantly affects the explosivity of volcanic eruptions
30.11.2016 | Johannes Gutenberg-Universität Mainz

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>