Statistical analysis of a characteristic shock formation distance for high-amplitude noise

Seismic reflection data obtained across the Quebec Appalachians using the VIBROSEIS (trademark Conoco) technique were recorded with parameters that allowed harmonic distortion arrivals to interfere with layered reflections. The data exhibit reflections from layered miogeoclinal rocks dipping eastward beneath the allochthonous rocks of the orogen; the layering appears to terminate beneath the Notre Dame Anticlinorium. However, as the apparent termination of the layers also occurs at the arrival times of high-amplitude noise harmonics, it may have no geological significance. Precambrian Grenville crust, which probably underlies the layered sediments, extends at least as far east as the apparent termination, and may extend much farther. Examination of the Bouguer gravity field in relation to the seismic reflection data shows that a major gravity change is due to density differences that occur considerably west of the eastern limit of Precambrian Grenville crust. The gravity thus shows no correlation with surface structures proposed as suture zones. An actualistic model incorporates subduction of a passive (Atlantic-type) margin beneath an arc terrain during the Ordovician.

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Influence of High-Amplitude Noise on Boundary-Layer Transition to Turbulence

10.21236/ada359230 ◽

1998 ◽

Cited By ~ 9

Author(s):

William S. Saric

Keyword(s):

Boundary Layer ◽

High Amplitude ◽

Boundary Layer Transition ◽

Transition To Turbulence ◽

Layer Transition ◽

Amplitude Noise

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NOISE EFFECTS ON THE ELECTROSENSE-MEDIATED FEEDING BEHAVIOR OF SMALL PADDLEFISH

Fluctuation and Noise Letters ◽

10.1142/s021947750100024x ◽

2001 ◽

Vol 01 (02) ◽

pp. L71-L86 ◽

Cited By ~ 9

Author(s):

DAVID F. RUSSELL ◽

ANNA TUCKER ◽

BARBARA A. WETTRING ◽

ALEXANDER B. NEIMAN ◽

LON WILKENS ◽

...

Keyword(s):

Feeding Behavior ◽

Stochastic Resonance ◽

Sensory Information ◽

High Amplitude ◽

Body Motion ◽

Electrical Noise ◽

Behavioral Experiments ◽

Noise Effects ◽

Amplitude Noise ◽

Spatial Range

Weak electrical noise applied in the water around small paddlefish, Polyodon spathula, increases the spatial range over which they can detect and capture planktonic prey (Daphnia), demonstrating stochastic resonance at the level of an animal's feeding behavior. Here we show that optimal-amplitude (~ 0.5 μ V · cm -1) noise causes a fish to prefer more vertical angles of attack when striking at prey, as revealed in polar graphs. Increased spatial range is also seen in horizontal directions, as outlying shoulders in the probability distribution of horizontal strike distances. High levels of noise increased the distance that approaching prey travelled along the rostrum (an elongated appendage anterior to the head, functioning as an electrosensitive antenna), before the fish first showed a visible fin or body motion in response. There was no significant effect of optimal-amplitude noise on the rate of strikes, although high-amplitude noise reduced the strike rate. The behavioral data were confirmed in neurophysiological experiments demonstrating that stochastic resonance occurs in individual electroreceptors, and in fact occurs at a similar optimal noise level as in behavioral experiments. We conclude that stochastic resonance can be demonstrated in the behavior of animals, and that animals can make use of the increased sensory information available during near-threshold environmental noise.

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