Acoustic methods are frequently used to monitor endangered marine mammal species. Advantages of acoustic methods over visual ones include the ability to detect submerged animals, to work at night, and to work in any weather conditions. A relatively inexpensive and easy-to-use acoustic float, the QUEphone, was developed by converting a...
The energy ratio mapping algorithm (ERMA) was developed to improve the performance of
energy-based detection of odontocete echolocation clicks, especially for application in environments
with limited computational power and energy such as acoustic gliders. ERMA systematically
evaluates many frequency bands for energy ratio-based detection of echolocation clicks produced
by a...
Full Text:
, Newport, Oregon 97365
(Received 23 February 2012; accepted 24 February 2012)
[DOI: 10.1121/1.3699190
The energy ratio mapping algorithm (ERMA) was developed to improve the performance of
energy-based detection of odontocete echolocation clicks, especially for application in environments
with limited computational power and energy such as acoustic gliders. ERMA systematically
evaluates many frequency bands for energy ratio-based detection of echolocation clicks produced
by a...
Full Text:
pilot whales). VC 2011 Acoustical Society of America. [DOI: 10.1121/1.3531924]
PACS number(s): 43.30.Sf
The energy ratio mapping algorithm (ERMA) was developed to improve the performance of
energy-based detection of odontocete echolocation clicks, especially for application in environments
with limited computational power and energy such as acoustic gliders. ERMA systematically
evaluates many frequency bands for energy ratio-based detection of echolocation clicks produced
by a...
Acoustic backscattering strength is often used as an index of biomass; however, the relationship between these variables has not been directly validated. Relationships were investigated between acoustic cross section at 200 kHz, measured as part of a previous study, and measured values of length, biovolume, dry weight, ash-free dry weight,...
Passive acoustic monitoring is a valuable tool for observing the status of marine environments. Comparisons of underwater soundscapes over temporal and spatial scales can provide data to inform marine conservation efforts, including protection of threatened and endangered species. This dissertation utilizes passive acoustic data collected via a broadly spaced array...
Fluctuations of the low frequency sound field in the presence of an internal solitary wave packet during the Shallow Water ’06 experiment are analyzed. Acoustic, environmental, and on-board ship radar image data were collected simultaneously before, during, and after a strong internal solitary wave packet passed through the acoustic track....
Monitoring marine ambient sound using standardized methods supports assessments of ocean sound levels across widespread ecosystems. This thesis quantifies differences among coastal and deep-water marine soundscapes in the Atlantic and Pacific oceans. The sources of sound in a soundscape are compartmentalized into three components and compared over time and among...
In 2009 two calibrated acoustic recorders were deployed in polar waters of the North Atlantic to study the seasonal occurrence of blue, fin, and sperm whales and to assess current ambient noise levels. Sounds from these cetaceans were recorded at both locations in most months of the year. During the...
Vocalizations of Indo-Pacific humpback dolphins (Sousa chinensis) in west Hong Kong waters were described from 12 recordings in 2010. A broadband hydrophone system recorded sounds. Vocalizations were characterized as broadband click trains, burst pulses, and narrowband frequency modulated sounds, including whistles generally similar to those of some other delphinid cetaceans....
Humpback whales produce a wide range of low-to mid-frequency vocalizations throughout their migratory range. Non-song "calls" dominate this species' vocal repertoire while on high-latitude foraging grounds. The source levels of 426 humpback whale calls in four vocal classes were estimated using a four-element planar array deployed in Glacier Bay National...
Preliminary results are presented from an analysis of mid-frequency acoustic transmission data collected at range 550m during the Shallow Water 2006 Experiment. The acoustic data were collected on a vertical array immediately before, during, and after the passage of a nonlinear internal wave on 18 August, 2006. Using oceanographic data...
During January–February 2009, an active-source seismic survey was performed over the Eastern Lau Spreading Center in the Lau Back-Arc Basin (21°S, 176°S). Acoustic signals generated by the R/V Langseth's 36-gun pneumatic source array were recorded within the deep sound channel at offsets of 29–416 km. The local ocean acoustic environment...
In late 2007, two massive icebergs, C19a and B15a, drifted into open water and slowly disintegrated in the southernmost Pacific Ocean. Archived acoustic records show that the high-intensity underwater sounds accompanying this breakup increased ocean noise levels at mid-to-equatorial latitudes over a period of ~1.5 years. More typically, seasonal variations...
Acoustic echo sounders designed to map and discriminate organisms in the water column have primarily been deployed on ships. Because of acoustic attenuation of higher frequencies used to detect and discriminate micronekton and nekton, this has effectively restricted the range of this information to the upper water column. In an...
Increasing public awareness that the Cascadia subduction zone in the Pacific Northwest is capable of great earthquakes (magnitude 9 and greater) motivates the Cascadia Initiative, an ambitious onshore/offshore seismic and geodetic experiment that takes advantage of an amphibious array to study questions ranging from megathrust earthquakes, to volcanic arc structure,...
One way to support the transgender and gender diverse (TGD) community is by calling out microaggressions. Bystander readiness to call out microaggressions may be influenced by a bystander’s perception of harm caused by the microaggression and stereotypes surrounding the identity of the microaggressor. In this study, I focused on the...
On low-latitude breeding grounds, humpback whales produce complex and highly stereotyped
songs as well as a range of non-song sounds associated with breeding behaviors. While on their
Southeast Alaskan foraging grounds, humpback whales produce a range of previously unclassified
non-song vocalizations. This study investigates the vocal repertoire of Southeast Alaskan...
Mid-ocean ridge volcanism and extensional faulting are the fundamental processes that lead to the creation and rifting of oceanic crust, yet these events go largely undetected in the deep ocean. Currently, the only means available to observe seafloor-spreading events in real time is via the remote detection of the seismicity...
This project uses field recordings to examine the levels of noise pollution present in both rural and urban areas by creating an artistic translation of these soundscapes, representative of how wild birds experience different environments. The field recordings capture not only what is present in a given soundscape, but what...