From mysticete song to odontocete echolocation: Monitoring cetacean sounds with high‐frequency acoustic recording packages (HARPs).

2009 ◽  
Vol 125 (4) ◽  
pp. 2615-2615
Author(s):  
Sean M. Wiggins ◽  
John A. Hildebrand
Keyword(s):  
High Frequency ◽  
Acoustic Recording

High‐frequency Acoustic Recording Package (HARP) for long‐term monitoring of marine mammals

2006 ◽  
Vol 120 (5) ◽  
pp. 3015-3015
Author(s):  
Sean M. Wiggins ◽  
Chris Garsha ◽  
Greg Campbell ◽  
John A. Hildebrand
Keyword(s):  
High Frequency ◽  
Marine Mammals ◽  
Long Term Monitoring ◽  
Acoustic Recording ◽  
Term Monitoring

scholarly journals Temporal patterns in the acoustic signals of beaked whales at Cross Seamount

2008 ◽  
Vol 4 (2) ◽  
pp. 208-211 ◽  
Author(s):  
D.W Johnston ◽  
M McDonald ◽  
J Polovina ◽  
R Domokos ◽  
S Wiggins ◽  
...  
Keyword(s):  
Surface Waters ◽  
High Frequency ◽  
Marine Mammals ◽  
Prey Capture ◽  
Prey Availability ◽  
Beaked Whale ◽  
Near Surface ◽  
Beaked Whales ◽  
Fisheries Acoustics ◽  
Acoustic Recording

Seamounts may influence the distribution of marine mammals through a combination of increased ocean mixing, enhanced local productivity and greater prey availability. To study the effects of seamounts on the presence and acoustic behaviour of cetaceans, we deployed a high-frequency acoustic recording package on the summit of Cross Seamount during April through October 2005. The most frequently detected cetacean vocalizations were echolocation sounds similar to those produced by ziphiid and mesoplodont beaked whales together with buzz-type signals consistent with prey-capture attempts. Beaked whale signals occurred almost entirely at night throughout the six-month deployment. Measurements of prey presence with a Simrad EK-60 fisheries acoustics echo sounder indicate that Cross Seamount may enhance local productivity in near-surface waters. Concentrations of micronekton were aggregated over the seamount in near-surface waters at night, and dense concentrations of nekton were detected across the surface of the summit. Our results suggest that seamounts may provide enhanced foraging opportunities for beaked whales during the night through a combination of increased productivity, vertical migrations by micronekton and local retention of prey. Furthermore, the summit of the seamount may act as a barrier against which whales concentrate prey.

High‐frequency Acoustic Recording Package (HARP) for long‐term monitoring of marine mammals

2005 ◽  
Vol 117 (4) ◽  
pp. 2525-2525 ◽  
Author(s):  
Sean Wiggins ◽  
Chris Garsha ◽  
Kevin Hardy ◽  
John Hildebrand
Keyword(s):  
High Frequency ◽  
Marine Mammals ◽  
Long Term Monitoring ◽  
Acoustic Recording ◽  
Term Monitoring

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

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