Untersuchung der akustischen Emission bei Bruchvorgängen in Salzgesteinen. (Investigation of acoustic emission of failure process in salt rocks)
Following to a consideration on general problems of acoustic emission it is discussed, if it is possible to predict the failure moment of salt rocks under uniaxial loading. For this reason amplitudes and impulse rates of acoustic emission from
Acoustic facies and seabed features of the mixed carbonate-siliciclastic deposits of the last eustatic cycle in the La Maddalena Archipelago (North Sardinia, Italy)
A high-resolution Chirp acoustic survey of 250 nautical miles performed in the La Maddalena Archipelago provided a scheme of the acoustic facies of the recentmost sediments and a frame of the large-scale bedforms linked to the last eustatic cycle
that characterize its channels. Five main acoustic facies have been recognized and mapped. Due to the good coherence with the sediment texture map of the area, an interpretation of the acoustic facies in sedimentary terms is presented. - (NF)
Higher frequency acoustic measurements of swash processes
Instrumentation is described here which measures the three-dimensional, nearbed flow field using a small ultrasonic current meter and the corresponding gravel transport using an acoustic probe to monitor self-generated noise. Laboratory flume
calibration of the probe confirmed the theoretical dependence of the local acoustic energy level on the bedload transport rate. A series of high frequency measurements in the swash zones on the beach at Chichester Harbow are described.
Problems in the calibration of an acoustic device for the observation of bedload transport
the necessary continuous or frequent record of variations at a single section. Acoustic techniques have the potential to overcome this deficiency, but their application has been very limited. Some of the problems of calibrating an acoustic device in the field
Investigating the transport dynamics and the properties of bedload material with a hydro-acoustic measuring system
The aim of this presentation is the introduction of the preparatory work for the implementation of a hydro-acoustic measuring system allowing the registration and recording of the bedload transport in real time. The signals were recorded by means
The paper presents some results of thermal structure and vertical air motion in the atmospheric boundary layer in Wroclaw and Mülheim an der Ruhr (Germany) based on acoustic sounding of atmosphere. This investigation is only the one part of a big
Three-dimensional measurement of river channel flow processes using acoustic doppler velocimetry
This paper describes and assesses : 1) the use of a new instrument for the determination of three-dimensional flow velocities in natural rivers, the acoustic Doppler velocimeter (ADV); and 2) a method for positioning and orienting such measurements
Acoustic emissions from two landslip areas in South Wales
Significant acoustic emissions have been recorded from two landslide sites, both subsequent to a major failure (Pantteg) and during continuous slow movement (Glynrhigos). Four distinct types of pedogenic AE have been recognised. The effects
Acoustic Doppler current profiler measurments in coastal and estuarine environments : examples from the Tay Estuary, Scotland
Acoustic Doppler current profilers (ADCPs) provide a means to measure the components of water current velocities in three dimensions. Using examples of ADCP datasets acquired from the macrotidal Tay Estuary, eastern Scotland, the principles of field
Measuring water velocity in highly turbulent flows : field tests of an electromagnetic current meter (ECM) and an acoustic Doppler velocimeter (ADV)
Two field tests were completed to compare the performance of an electromagnetic current meter (ECM) with that of an acoustic Doppler velocimeter (ADV) in gravel-bed rivers. Research was particularly motivated by the need to measure flow properties
Measuring flow velocity and sediment transport with an acoustic Doppler current profiler
The aim of this paper is to review and evaluate an acoustic Doppler current profiler (aDep) for measurements of flow velocity, bed load and suspended load in fluvial and lacustrine environments. Examples are provided from the Fraser Estuary
Self-generated noise (SGN) is a passive acoustic technique for the measurement of bedload transport through the acoustic detection of intergranular collisions using a submerged hydrophone system. SGN is of interest because of the possibilities