Using acoustic monitoring to observe and interrelate ambient noise, sea ice dynamics, marine mammal distributions, and anthropogenic activity in the Alaskan Arctic
Abstract
In recent years, the Western Arctic has been on the verge of a fundamental shift towards seasonal ice cover as indicated by record lows in sea ice thickness. Not only are the sources of underwater sound production changing, but acoustic propagation near the sea surface may be altered as well. Since 2006, autonomous seafloor recorders known as High-frequency Acoustic Recording Packages (HARPs) have been monitoring areas north of Barrow, Alaska - ranging from 50-200 km offshore - on the shelf break between the shallow Chukchi and deep Beaufort Seas. Broadband, near-continuous data collection is providing unique insight into Arctic acoustic ecology through studies in natural ambient sound, bioacoustics, and anthropogenic noise during all seasons of the year. Our research integrates large-scale remote sensing data across large time scales in order to explore the intricate seasonal variability related to event-based correlations between local sea ice conditions and sound-pressure levels. With this sparse array of non-collocated offshore sites, we are observing changes in the underwater sound field as well as the acoustic presence and calling behavior of marine mammals, while comparing with trends in sea ice dynamics, wind speed, and anthropogenic activity. After several years of instrument deployments, this time series is beginning to show fluctuations in underwater noise levels in addition to the offshore distribution of ice-related marine mammals over seasonal time scales. By statistically quantifying the distribution of noise levels across the sound spectrum, we examine the cumulative contribution of noise from seismic exploration surveys that have been occurring in both the Chukchi and Beaufort Seas over several months of each year since 2006.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFMGC43B0969R
- Keywords:
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- 0700 CRYOSPHERE;
- 1635 GLOBAL CHANGE / Oceans;
- 4207 OCEANOGRAPHY: GENERAL / Arctic and Antarctic oceanography;
- 4259 OCEANOGRAPHY: GENERAL / Ocean acoustics