Infrasonic monitoring of snow-avalanche activity: What do we know and where do we go from here?

Valík, Adam; Chritin, V.; Rossi, Michel J.; Lancker, E. van

doi:10.3189/1998aog26-1-324-328

Cited by 13 publications

(7 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Beside quality concerns of man-made observations, it is no more acceptable to have no data in adverse weather, just because the low visibility prevents making any observations. Promising approaches based on acoustic (Adam et al, 1998;Duclos et al, 2001) and seismic techniques (Ammann, 1998;Suriñach et al, 2001) are presently under development and no effort should be spared to operationally implement such systems.…”

Section: Discussionmentioning

confidence: 99%

Untitled

Laternser

Schneebeli

2002

Natural Hazards

View full text Add to dashboard Cite

Avalanche observations are an important factor for operational avalanche warning and the main parameter to carry out an objective verification of the avalanche bulletin in retrospect. For the first time, a 50-year long series of avalanche activity data of 84 Swiss avalanche observation stations is analysed and discussed. After careful data preparation a regional avalanche activity index (RAAI) for seven snow-climatological regions of Switzerland was developed. Using different statistical descriptors, we were unable to detect a long-term change in avalanche activity, which stands in contrast to a significant increase of winter precipitation. The comparison of the RAAI with a comprehensive database for destructive avalanches (DADB) resulted in a low correlation. This shows clearly the difficulties involved in determining a good measure for specifying the true avalanche activity. Depending on the degree of the avalanche activity DADB and avalanche observations represent the avalanche activity differently and overlap. Suggestions are given for the improvement of the ongoing avalanche observation programme in order to achieve an overall consistent and reliable data set in future.

show abstract

Section: Discussionmentioning

confidence: 99%

Untitled

Laternser

Schneebeli

2002

Natural Hazards

View full text Add to dashboard Cite

show abstract

“…After the pioneering study by Bedard (1989), the use of the infrasound in avalanche monitoring and research has increased significantly (Chritin et al, 1996;Adam et al, 1998;Comey and Mendenhall, 2004). Naugolnykh and Bedard (1990) suggested that infrasound is possibly induced by the non-stationary motion and/or by the turbulence of the flow.…”

Section: Introductionmentioning

confidence: 99%

Seismo-acoustic energy partitioning of a powder snow avalanche

Marchetti

Herwijnen²,

Christen³

et al. 2020

Earth Surf. Dynam.

View full text Add to dashboard Cite

Abstract. While flowing downhill, a snow avalanche radiates seismic waves in the ground and infrasonic waves in the atmosphere. Seismic energy is radiated by the dense basal layer flowing above the ground, while infrasound energy is likely radiated by the powder front. However, the mutual energy partitioning is not fully understood. We present infrasonic and seismic array data of a powder snow avalanche, which was released on 5 February 2016, in the Dischma valley above Davos, Switzerland. A five-element infrasound array, sensitive above 0.1 Hz, and a seven-element seismic array, sensitive above 4.5 Hz, were deployed at a short distance (<500 m) from each other and close (<1500 m) to the avalanche path. The avalanche dynamics were modelled by using RAMMS (rapid mass movement simulation) and characterized in terms of front velocity and flow height. The use of arrays rather than single sensors allowed us to increase the signal-to-noise ratio and to identify the event in terms of back-azimuth angle and apparent velocity of the recorded wave fields. Wave parameters, derived from array processing, were used to identify the avalanche path and highlight the areas, along the path, where seismic and infrasound energy radiation occurred. The analysis showed that seismic energy is radiated all along the avalanche path, from the initiation to the deposition area, while infrasound is radiated only from a limited sector, where the flow is accelerated and the powder cloud develops. The recorded seismic signal is characterized by scattered back-azimuth angle, suggesting that seismic energy is likely radiated by multiple sources acting at once. On the contrary, the infrasound signal is characterized by a clear variation of back-azimuth angle and apparent velocity. This indicates that infrasound energy radiation is dominated by a moving point source, likely consistent with the powder cloud. Thanks to such clear wave parameters, infrasound is revealed to be particularly efficient for avalanche detection and path identification. While the infrasound apparent velocity decreases as the flow moves downhill, the seismic apparent velocity is quite scattered but decreases to sound velocity during the phase of maximum infrasound radiation. This indicates an efficient process of infrasound to seismic energy transition, which, in our case, increases the recorded seismic amplitude by ∼20 %, at least in our frequency band of analysis. Such an effect can be accounted for when the avalanche magnitude is estimated from seismic amplitude. Presented results clearly indicate how the process of seismo-acoustic energy radiation by a powder avalanche is very complex and likely controlled by the powder cloud formation and dynamics, and the process is hence affected by the path geometry and snow characteristics.

show abstract

“…Since many important phenomena produce sound, the amount of research conducted in the fields of acoustic goniometry and infrasonic monitoring is not surprising. Researchers have focused on a variety of facets including applications for acoustic goniometers and infrasonic monitoring, improvements to sensor hardware, and efficient/effective firmware design [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. This section details a small sample of the research that has been conducted and the technology used in the process.…”

Section: Previous Workmentioning

confidence: 99%

A Small Acoustic Goniometer for General Purpose Research

Pook

Loo

2016

Sensors

View full text Add to dashboard Cite

Understanding acoustic events and monitoring their occurrence is a useful aspect of many research projects. In particular, acoustic goniometry allows researchers to determine the source of an event based solely on the sound it produces. The vast majority of acoustic goniometry research projects used custom hardware targeted to the specific application under test. Unfortunately, due to the wide range of sensing applications, a flexible general purpose hardware/firmware system does not exist for this purpose. This article focuses on the development of such a system which encourages the continued exploration of general purpose hardware/firmware and lowers barriers to research in projects requiring the use of acoustic goniometry. Simulations have been employed to verify system feasibility, and a complete hardware implementation of the acoustic goniometer has been designed and field tested. The results are reported, and suggested areas for improvement and further exploration are discussed.

show abstract

Infrasonic monitoring of snow-avalanche activity: What do we know and where do we go from here?

Cited by 13 publications

References 4 publications

Untitled

Untitled

Seismo-acoustic energy partitioning of a powder snow avalanche

A Small Acoustic Goniometer for General Purpose Research

Contact Info

Product

Resources

About