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81.
Observations and implications of damage from the magnitude Mw 6.3 Christchurch, New Zealand earthquake of 22 February 2011 总被引:1,自引:1,他引:0
Sean Wilkinson Damian Grant Elizabeth Williams Sara Paganoni Stuart Fraser David Boon Anna Mason Matthew Free 《Bulletin of Earthquake Engineering》2013,11(1):107-140
This paper describes the observations made by a reconnaissance team following the 22nd February 2011, Mw 6.3, Christchurch, New Zealand earthquake (GNS Science, 2011). The team comprised of members of the UK based Earthquake Engineering Field Investigation Team who spent 5 days collecting observations on damage resulting from the earthquake. Although the magnitude of this earthquake was not particularly high (Mw 6.3), the shallow focus and close proximity resulted in locally very high ground motions, widespread damage and 182 fatalities. The earthquake is also particularly notable for the widespread liquefaction it caused, landslides and rockfalls in the hills south of Christchurch, and the significant damage suffered by unreinforced masonry and historic structures. Over wide areas of central Christchurch, recorded accelerations were in excess of those required by the current New Zealand seismic loadings standard (NZS1170.5:2004: Standards New Zealand 2004) and therefore the earthquake presented a valuable opportunity to assess performance of modern buildings under code-level ground acceleration. 相似文献
82.
At the Sandpiper gold deposit in the Tanami region of northern Australia sericite is intimately intergrown with arsenopyrite in gold-bearing quartz veins and breccias, suggesting sericite crystallisation synchronous with gold-bearing fluid flow. This ore-stage sericite yields a 40Ar/39Ar plateau age of 1785 ± 32 Ma (2σ including both analytical and systematic uncertainties). Recalculation using revised and more precise values for the 40K decay constants and the age of the Fish Canyon Sanidine standard shifts the age to 1794 ±12 Ma (2σ including all known uncertainties). Given the possibility of post-mineralisation isotopic resetting this age can be conservatively interpreted as a minimum constraint on the timing of gold deposition although, given local geological relationships and estimates for the argon retentivity of white mica, we consider complete isotopic resetting to be unlikely. The preferred interpretation is, therefore, that the sericite 40Ar/39Ar age indicates the timing of gold mineralisation. Thesericite age accords with a limited dataset of 207Pb/206Pb xenotime ages of ca 1800 Ma from other gold deposits in the Tanami region, interpreted as mineralisation ages. The agreement between independently derived ages from several gold deposits lends support for a widespread gold-mineralising event at ca 1800 Ma in the Tanami region. 相似文献
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Helen J. Fraser † Mark P. Collings Martin R. S. McCoustra David A. Williams 《Monthly notices of the Royal Astronomical Society》2001,327(4):1165-1172
Water (H2 O) ice is an important solid constituent of many astrophysical environments. To comprehend the role of such ices in the chemistry and evolution of dense molecular clouds and comets, it is necessary to understand the freeze-out, potential surface reactivity and desorption mechanisms of such molecular systems. Consequently, there is a real need from within the astronomical modelling community for accurate empirical molecular data pertaining to these processes. Here we give the first results of a laboratory programme to provide such data. Measurements of the thermal desorption of H2 O ice, under interstellar conditions, are presented. For ice deposited under conditions that realistically mimic those in a dense molecular cloud, the thermal desorption of thin films (≪50 molecular layers) is found to occur with zeroth-order kinetics characterized by a surface binding energy, E des , of 5773 ± 60 K, and a pre-exponential factor, A , of 1030 ± 2 molecules cm−2 s−1 . These results imply that, in the dense interstellar medium, thermal desorption of H2 O ice will occur at significantly higher temperatures than has previously been assumed. 相似文献
86.
B. J. Fraser 《Planetary and Space Science》1982,30(12):1229-1238
Ion cyclotron waves generated in the magnetosphere by the ion cyclotron instability of protons are thought to be the origin of Pc 1–2 geomagnetic pulsations. Propagation characteristics of these waves have been measured using ATS-6 synchronous satellite magnetometer wave data. Of particular interest are the wave spectra, polarization properties, and wave diagnostics; all are characteristic of propagation in a cool ambient magnetospheric plasma containing He+ and O+ heavy ions. 相似文献
87.
REFRACTION CONSIDERATIONS FOR PHOTOGRAMMETRIC MEASUREMENTS IN A THERMAL VACUUM CHAMBER 总被引:1,自引:1,他引:0
C. S. Fraser 《The Photogrammetric Record》1992,14(79):99-112
88.
Lateglacial and Holocene relative sea‐level changes and first evidence for the Storegga tsunami in Sutherland,Scotland 下载免费PDF全文
Antony J. Long Natasha L. M. Barlow Sue Dawson Jon Hill James B. Innes Catherine Kelham Fraser D. Milne Alastair Dawson 《第四纪科学杂志》2016,31(3):239-255
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Land use patterns influence the long-term productivity of agro-ecosystems and result from socio-economic as well as biophysical and climatic drivers. This paper qualitatively examines how past demographic and political-economic changes in southern Romania twice led to vulnerable socio-economic and agro-ecological systems. Drawing on this case study, we establish broad-brush hypotheses identifying some of the potential causes of vulnerability. We suggest that vulnerable systems appear more likely to occur when socio-political uncertainty combines with a lack of off-farm employment in regions where there are abundant natural capital stocks that can be quickly liquidated. 相似文献