Polar Underwater Sounds Library
This is the Polar Underwater Sound Library which should give a small glimps of sounds encountered by our scientific research. For presentational purposes we are only presenting results of our Sample Site PALAOA.
Antarctic minke whale (Balaenoptera bonaerensis)
The Antarctic minke whale is the smallest rorqual occuring in Antarctic Seas. In contrast to other baleen whale species, this small whale is regulary sighted near the ice edge but also occurs within the pack ice. The Antarctic minke whale produces a very unique sound termed the bio-duck which are repetitive sequences of pulsed sounds between 50 – 300 Hz with harmonics up to 1500 Hz. PALAOA records different bio-duck types during the months of June to November.
Antarctic blue whale (Balaenoptera musculus intermedia)
The low frequency calls of blue whales belong to the loudest vocalizations produced by any animal. Most likely blue whales communicate with these vocalizations over long distances. PALAOA recorded different blue whale vocalizations.
Killer whale (Orcinus orca)
In the Southern Ocean, three killer whale sub-species co-exist which are specialized on different prey species and vary slightly in their visual appearance. Killer whales, also called Orcas, produce a variety of vocalizations, for example whistles or echolocation clicks.
Humpback whale (Megaptera novaeangliae)
The typical whale songs which are known from other media, are usually produced by humpback whales. The Southern Hemisphere humpback whales spend the summer in the Southern Ocean to feed as much as possible. Reproduction and breeding mainly takes place in tropical waters. At PALAOA, humpback whale songs are not recorded, but 24 different social call types are regularly recorded.
Sperm whale (Physeter macrocephalus)
Sperm whales produce a variety of clicking sounds. During foraging dives they emit so-called usual clicks with regularly spacing and creaks (short series of clicks with fast repetition rate, close to prey encounter). In social context they produce codas which are repeated patterns of clicks. Different groups of sperm whales use different codas (dialects) and within a group codas can vary slightly by individuals. At PALAOA we recorded usual clicks.
Crabeater seal (Lobodon carcinophaga)
The crabeater seal vocalizes especially during the breeding season between October and December. Although the males do not defend underwater territories, they guard a single female on the ice until it is ready for conception. The crabeater seal vocal repertoire at PALAOA consists of two call types.
Leopard seal (Hydrurga leptonyx)
In leopard seals, females are bigger than the males. During the breeding period PALAOA detects vocalizations of both males and females. Due to the fact that leopard seals are solitary animals, they can use their vocalizations to find a mate. At PALAOA, so far, seven distinct leopard seal vocalizations were recorded.
Ross seal (Ommatophoca rossii)
The Ross seal is the least investigated Antarctic seal species. Ross seals live in the poorly accessible pack ice and also in areas of open water. PALAOA provides us with unique recordings of their underwater conversations. Five different call types were identified so far: high, middle, and low frequency sirens, a tonal call and the “Whoosh”.
Weddell seal (Leptonychotes weddellii)
The Weddell seal lives inside the dense sea ice. At PALAOA we can hear its vocalizations almost all year-round (Exceptions: February). Weddell seals have a large vocal repertoire, of which 14 call types were recorded at PALAOA. Some of these sounds are probably produced to defend underwater territories.
Many sounds which are recorded by PALAOA, cannot be identified by scientists. Often it is not even possible to tell if the sounds originate from animals or if these are abiotic. The acoustic example displays a mysterious low-pitched sound. Scientists verified that this sound was recorded when no ship was present within a radius of 1000 km.
Very Long Sound
Calving ice shelf
From time to time, large pieces of the Antarctic ice shelf break off (calve) and crash into the ocean. This process is called calving. The animals in the water seem not to be disturbed by these sounds, already shortly after these loud noises, pinnipeds are heard again in the recordings.
Rubbing of ice floes
The underwater soundscape of the Southern Ocean is dominated by the sounds of ice. These sounds are generated when ice floes rub against each other or bend.
Colliding ice bergs
The most intense sounds recorded by the PALAOA station originate from the collision of two ice bergs.
(Relatively) Quiet Ocean
The Southern Ocean is one of the last nearly pristine areas of the world’s oceans.
Twice a year, the German research vessel Polarstern visits the Atka bay to deliver supplies to the Neumayer Station. These visits leave clear acoustic signatures in the PALAOA recordings.
"Singing" ice bergs
The exact process generating these sounds is not investigated yet. However, it is known that these sounds are produced by the movements of icebergs.