Calculation of the Deviatoric Stress Field in New Zealand

10.26686/wgtn.17068658.v1 ◽

2021 ◽

Author(s):

◽

Hamish Hirschberg

Keyword(s):

New Zealand ◽

Stress Field ◽

Balance Equation ◽

Thin Sheet ◽

Low Noise ◽

Deviatoric Stress ◽

Gravitational Potential Energy ◽

Noise Levels ◽

Step Method ◽

Deviatoric Stresses

<p>I model the vertically averaged deviatoric stress field for New Zealand using velocity and crustal density data. I use a thin sheet model of a viscously deforming lithosphere, averaging over a depth of 100 km and solve the stress balance equation. Two methods of solving the stress balance equation are compared: one method solves first for deviatoric stresses due to gravitational potential energy per unit volume before accounting for deviatoric stresses due to boundary conditions; the other method assumes an isotropic viscosity to relate deviatoric stress to strain rate, solving for the viscosity field. Under synthetic testing, the two step method is able to cope with high levels of noise but contains edge effects. The method solving for viscosity is accurate at low noise levels, however, it is unreliable at high noise levels. I apply the two step method to New Zealand using a Quaternary and a GPS-derived velocity model. Vertically averaged deviatoric stress magnitudes are found to be 10-30 MPa, similar to magnitudes found for other plate-boundary zones. Gravitational and boundary stresses each account for approximately half of the full deviatoric stress. Effective viscosities are found to be 1-10×10²¹ Pa s in the regions of most active deformation, which can be interpreted in terms of the long term strength of the lithosphere controlled by temperature and/or lithology.</p>

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The effect of a deviatoric stress on physical rock properties. An experimental study simulating the in-situ stress field at the KTB drilling site, Germany

International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts ◽

10.1016/0148-9062(95)93294-y ◽

1995 ◽

Vol 32 (5) ◽

pp. A222

Keyword(s):

Experimental Study ◽

Stress Field ◽

In Situ Stress ◽

Deviatoric Stress ◽

Rock Properties ◽

Drilling Site ◽

In Situ Stress Field ◽

Physical Rock Properties ◽

Physical Rock

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Blow-Down Valve Noise and Interactions With Downstream Orifice Plates

Noise Control and Acoustics ◽

10.1115/imece2003-55111 ◽

2003 ◽

Author(s):

Denis G. Karczub ◽

Fred W. Catron ◽

Allen C. Fagerlund

Keyword(s):

Noise Exposure ◽

Control Valve ◽

Low Noise ◽

Noise Levels ◽

Exposure Limits ◽

Blow Down ◽

Gas Processing ◽

The Impact ◽

Acoustic Fatigue ◽

Infrequent Event

In a blow-down situation as might occur at a natural gas processing facility, noise levels are very high and significantly exceed the noise levels one would normally associate with a control valve. As the blow-down operation is an infrequent event, this may be permissible but requires consideration of the duration of these high noise levels to ensure that occupational noise exposure limits and acoustic fatigue limits are not exceeded. Tests of noise levels due to an 8-inch control valve in a 12-inch pipeline under blow-down conditions are compared here with noise level predictions based on the IEC standard. Consideration is also given to the impact of placing an orifice plate downstream of the control valve as is often done to reduce pressure drop across the valve in the expectation that control valve noise levels will be reduced. Simple orifice plates often installed by plant operators to achieve this goal are shown to have an adverse impact, and it is shown that a multi-hole diffuser or low-noise control valve should instead be used.

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Modeling heterogeneous deviatoric stress field around the hypocentral area of the 2005 Fukuoka earthquake (M7.0) by spatially distributed moment tensors

Journal of Geophysical Research Atmospheres ◽

10.1029/2011jb008687 ◽

2012 ◽

Vol 117 (B3) ◽

Cited By ~ 6

Author(s):

Satoshi Matsumoto ◽

Kenji Uehira ◽

Takeshi Matsushima ◽

Hiroshi Shimizu

Keyword(s):

Stress Field ◽

Deviatoric Stress ◽

Moment Tensors ◽

Spatially Distributed

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A Discussion of Pod Drives and Their Application In the Pleasure Boat Market

10.5957/pss-2009-17 ◽

2009 ◽

Author(s):

Christopher Swanhart

Keyword(s):

North America ◽

General Information ◽

Low Noise ◽

Noise Levels ◽

Propulsion Systems ◽

Fully Integrated ◽

Operator Interface ◽

Performance System ◽

Hull Forms

Since being introduced to North America at the Miami Boat Show in 2005, Volvo Penta Inboard Performance System, or IPS has established itself as a leading propulsion choice among pleasure boat owners and builders. Other suppliers are following suit including the Cummins Mercruiser Zeus system. Pod propulsion offers benefits like increased efficiency, better performance, nimble handling, and low noise levels while allowing more people to successfully operate their vessel due to a friendly operator interface. Features of these commercial pod systems that also benefit builders include ease of installation and the integral underwater exhaust which helps to meet CE requirements, for both exhaust and noise levels. Both IPS and Zeus are fully integrated pod propulsion systems. Existing vessels can be retro-fitted with these systems while many new vessels are being designed specifically for IPS or Zeus. Donald L. Blount and Associates provides consulting in regards to IPS integration with existing and new designs and has also been involved with designs employing the Zeus system. The first portion of this paper discusses pod drives, particularly IPS itself. (Because the author has substantially more experience and background with IPS, much of the information herein is IPS specific). General information on IPS and Zeus is offered as well as some operational specifics. The paper then focuses on the application of pod drives in existing and new vessel designs. The discussion includes how hull forms can be evaluated for use with pod drives. A look at the integration of pod systems into various types of pleasure boats (cruiser, day boat, fishing yacht, etc) is also covered including the challenges which exist for each specific vessel type.

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Mapping Stress and Structure From Subducting Slab to Magmatic Rift: Crustal Seismic Anisotropy of the North Island, New Zealand

10.26686/wgtn.12309776.v1 ◽

2020 ◽

Author(s):

Finnigan Illsley-Kemp ◽

Martha Savage ◽

Colin Wilson ◽

S Bannister

Keyword(s):

New Zealand ◽

Stress Field ◽

Large Scale ◽

Seismic Anisotropy ◽

Taupo Volcanic Zone ◽

Volcanic Zone ◽

The North ◽

Magma Reservoirs ◽

Tectonic Forces ◽

Subducting Slab

© 2019. American Geophysical Union. All Rights Reserved. We use crustal seismic anisotropy measurements in the North Island, New Zealand, to examine structures and stress within the Taupō Volcanic Zone, the Taranaki Volcanic Lineament, the subducting Hikurangi slab, and the Hikurangi forearc. Results in the Taranaki region are consistent with NW-SE oriented extension yet suggest that the Taranaki volcanic lineament may be controlled by a deep-rooted, inherited crustal structure. In the central Taupō Volcanic Zone anisotropy fast orientations are predominantly controlled by continental rifting. However at Taupō and Okataina volcanoes, fast orientations are highly variable and radial to the calderas suggesting the influence of magma reservoirs in the seismogenic crust (≤15 km depth). The subducting Hikurangi slab has a predominant trench-parallel fast orientation, reflecting the pervasive presence of plate-bending faults, yet changing orientations at depths ≥120 km beneath the central North Island may be relics from previous subduction configurations. Finally, results from the southern Hikurangi forearc show that the orientation of stresses there is consistent with those in the underlying subducting slab. In contrast, the northern Hikurangi forearc is pervasively fractured and is undergoing E-W compression, oblique to the stress field in the subducting slab. The north-south variation in fore-arc stress is likely related to differing subduction-interface coupling. Across the varying tectonic regimes of the North Island our study highlights that large-scale tectonic forces tend to dictate the orientation of stress and structures within the crust, although more localized features (plate coupling, magma reservoirs, and inherited crustal structures) can strongly influence surface magmatism and the crustal stress field.

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Dietrich et al. Magnetic resonance noise measurements and signal-quantization effects at very low noise levels. Magn Reson Med 2008;60:1477-1487.

Magnetic Resonance in Medicine ◽

10.1002/mrm.22043 ◽

2009 ◽

Vol 62 (1) ◽

pp. 277-278

Author(s):

Olaf Dietrich ◽

José G. Raya ◽

Maximilian F. Reiser

Keyword(s):

Magnetic Resonance ◽

Low Noise ◽

Noise Levels ◽

Signal Quantization ◽

Noise Measurements

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A high-sensitivity strain/inertial seismograph installation

Bulletin of the Seismological Society of America ◽

10.1785/bssa0600061803 ◽

1970 ◽

Vol 60 (6) ◽

pp. 1803-1822 ◽

Cited By ~ 4

Author(s):

James E. Fix ◽

John R. Sherwin

Keyword(s):

Environmental Control ◽

Earth Tide ◽

High Sensitivity ◽

Low Noise ◽

Photographic Film ◽

Noise Levels ◽

Directional Response ◽

Long Period ◽

Phase Velocities ◽

Short Period

Abstract A seismograph complex consisting of short-period (SP), long-period (LP), and extended long-period (XLP) inertial and strain seismographs has been installed. Recordings are made on magnetic tape and photographic film. Routine magnifications on the 20-trace, 16-mm film recorders for all three components are: SP inertial, 500 K; LP inertial, 100 K. The noise levels permit equivalent magnifications on the strain seismographs. The complex provides seismic wave discrimination by directional response, which is independent of period, and by detection of differences in phase velocities between P, S, Love, or Rayleigh arrivals. The strain seismographs use 40-m-long rods and moving coil transducers with generator constants of 32,000 v/m/sec. They sense waves of 5 × 10-13 strain at 30 sec and reject the 2 × 10-8 earth-tide strain. A low-noise preamplifier drives a filter assembly which provides SP, LP, and XLP strain outputs. The complex is installed in an abandoned mine 50 km southeast of Phoenix, Arizona. Environmental control is provided by burial at a depth of about 110 m in a quartz diorite, by sealing the mine, and by insulating the seismometers.

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Noise in an inpatient hospital ward in New Zealand

Building Acoustics ◽

10.1177/1351010x20916120 ◽

2020 ◽

Vol 27 (4) ◽

pp. 299-309

Author(s):

Thomas Hulland ◽

Andy Su ◽

Michael Kingan

Keyword(s):

New Zealand ◽

Experimental Method ◽

Total Duration ◽

Hospital Ward ◽

Noise Levels ◽

Noise Sources ◽

Inpatient Hospital

This article describes an investigation into the noise levels which patients are exposed to in a general inpatient hospital ward in New Zealand. An initial noise survey was conducted over a period of nine consecutive days in order to establish the noise levels in the ward. It was identified that noise levels increased dramatically between 4:00 a.m. and 7:00 a.m. In order to identify the sources of noise during this period, three noise surveys were undertaken between 4:30 a.m. and 7:00 a.m. on typical weekdays using a microphone placed inside a shared bedroom. During the noise survey, an observer identified the noise sources and their locations for significant noise events. Noise sources were then categorised into three main groups based on the character of the source (machine, staff or patient). Staff noise was found to account for 64% of the total duration of significant noise events (29% of the number of events) which occurred during the observations compared with 20% from patients (43% of the number of events) and 16% from machines (28% of the number of events). It was found that many staff and machine noise events could be mitigated or eliminated. Methods for mitigating noise are suggested and an experimental method was used to estimate the likely reduction in noise which could be attained by moving a staff conversation from the corridor outside the observed bedroom to other locations on the ward.

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