OREGON STATE UNIVERSITY

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Long-term Acoustic Real-Time Sensor for Polar Areas (LARA)

To acoustically monitor marine mammals, ambient noise levels, seismic activity, and other signals of interest and to report detected acoustic events back to shore in near-real-time.

The primary focus of LARA project is to develop a system which allows to acoustically monitor marine mammals, ambient noise levels, seismic activity, and other signals of interest and to report detected acoustic events back to shore in near-real-time. LARA will feature an ice sensing algorithm and is intended to improve long-term monitoring capabilities (one year duration) in potentially ice-covered areas such as the Arctic.

Project description:

Most state-of-the-art autonomous passive acoustic monitoring packages are designed to be moored in deep water and stay submerged for the entire deployment period.  Such deep-moored instruments are advantageous as [a] they are not subject to the wear and tear caused by surface waves, [b] ocean currents decrease with depth, making it easier to maintain the position of such a device, [c] devices can be below the thermocline, leading to longer ranges for acoustic sensing, and [d] they are not subject to vandalism, which has been problematic for remote moorings in some areas. However, in the past deep-moored instruments have been archival instruments, for which it is not possible to access data, gain timely information on the presence of acoustic signals of interest (such as marine mammal vocalizations or seismic event), or identify system malfunctions prior to instrument recovery. Furthermore, it is not possible to use GPS to update the system clock, which can drift significantly during long-term deployments and hinder accurate localization of sound sources when using multiple instruments in an array configuration (e.g., for tracking vocalizing animals or locating earthquakes). A few passive acoustic monitoring systems use a surface buoy to overcome some of these disadvantages. However, these systems cannot be reliably operated in polar areas with potential ice coverage. In addition, surface buoys are exposed to ocean surface waves, which can cause cable strumming and introduce acoustic noise. Surface buoys can also be damaged by collisions with vessels or by vandalism. The Long-term Acoustic Real-Time Sensor for Polar Areas (LARA) combines the advantages of both the submerged and surface systems. This real-time information system makes stationary passive acoustic monitoring more effective, and provides maximum flexibility, allowing a wide range of applications even in ice-covered areas. Potential applications include but are not limited to: real-time monitoring of marine mammals (detection, classification, localizing/tracking) and ambient noise levels, real-time reporting of seismic events for rapid responses (e.g., eruption of undersea volcanoes), real-time information on oceanographic conditions and sound propagation conditions in the upper 300 m of the water column.

Project members: 
Principle Investigator
Location: 

Arctic Ocean

United States
Latitude: 70.393119
Longitude: -161.495298

Funding Source

Co-PIs: Haru Matsumoto, David Mellinger, Robert Dziak (all OSU & NOAA/PMEL)
Partners: Chris Meinig (NOAA/PMEL)

Tags

Ecology
Technology