对F Rolandone等所作“沿圣安德烈斯断层蠕变部分的无震滑动和垂直断层应变”一文的评论

Rolandone等2008年报告了加州中部邻近圣安德烈斯蠕变部分的应变率的估计值。其中部分应变率估计值是基于从短程数据（例如2003年4月-2004年8月）推出的遗迹速度（其中包括2003．975圣锡米恩和2004．744帕克菲尔德地震的同震校正）。     

Ambient noise Rayleigh wave tomography of New Zealand

We present the first New Zealand-wide study of surface wave dispersion, using ambient noise observed at 42 broad-band stations in the national seismic network (GeoNet) and the Global Seismic Network (GSN). Year-long vertical-component time-series recorded between 2005 April 1 and 2006 March 31 have been correlated with one another to yield estimated fundamental mode Rayleigh wave Green's functions. We filter these Green's functions to compute Rayleigh wave group dispersion curves at periods of 5–50 s, using a phase-matched filter, frequency–time analysis technique. The uncertainties of the measurements are estimated based on the temporal variation of the dispersion curves revealed by 12 overlapping 3-month stacks. After selecting the highest quality dispersion curve measurements, we compute group velocity maps from 7 to 25 s period. These maps, and 1-D shear wave velocity models at four selected locations, exhibit clear correlations with major geological structures, including the Taranaki and Canterbury Basins, the Hikurangi accretionary prism, and previously reported basement terrane boundaries.     

Imaging the Hikurangi subduction zone, New Zealand, using teleseismic receiver functions: crustal fluids above the forearc mantle wedge

We image the Hikurangi subduction zone using receiver functions derived from teleseismic earthquakes. Migrated receiver functions show a northwest dipping low shear wave feature down to 60 km depth, which we associate with the crust of the subducted Pacific Plate. Receiver functions (RF) at several stations also show a pair of negative and positive polarity phases with associated conversion depths of ∼20–26 km, where the subducted Pacific Plate is at a depth of ∼40–50 km beneath the overlying Australian Plate. RF inversion solutions model these phases with a thin low S -wave velocity zone less than 4 km thick, and an S -wave velocity contrast of more than ∼0.5 km s⁻¹ with the overlying crust. We interpret this phase pair as representing fluids near the base of the lower crust of the Australian Plate, directly overlying the forearc mantle wedge.     

Astrometry of Southern radio sources

An overview is presented of a number of astrometry and astrophysics programs based on radio sources from the Parkes 2.7 GHz catalogues. The programs cover the optical identification and spectroscopy of flat-spectrum Parkes sources and the determination of their milliarc-second radio structures and positions. Work is also in progress to tie together the radio and Hipparcos positional reference frames. A parallel program of radio and optical astrometry of southern radio stars is also under way.     

Non-destructive assessment of polycyclic aromatic hydrocarbon (PAH) exposure by fluorimetric analysis of crab urine

The detection of urinary polycyclic aromatic hydrocarbon (PAH) metabolites by fluorescence spectrophotometry is particularly effective as a practical means to assess PAH exposure in decapod crabs. However, the practical application of this technique has thus far only been tested for the European shore crab (Carcinus maenas) and only a few field studies have been conducted in heavily polluted areas. The present study evaluated the adaptability of this method as a rapid, cost-effective and non-destructive biomonitoring tool for the New Zealand crab species, Macrophthalmus hirtipes (stalk-eyed mud crab). A field gradient could be detected among the sites and different input sources of PAH contamination could be discerned through the differentiation of pyrogenic and petrogenic PAH signatures. The present study shows that the fluorescence screening method is sensitive to relatively low levels of PAH contamination and more broadly applicable to smaller crab species than C. maenas, for which the technique was developed.     

Cyanide Chemistry in Comet Hale-Bopp (C/1995 O1)

Observations of comet Hale-Bopp (C/1995 O1) have been carried out near perihelion (1997 March) at millimeter wavelengths using the NRAO 12 m telescope. The J=1-->0, 2-->1, and 3-->2 lines of HCN at 88, 177, and 265 GHz were measured in the comet as well as the J=3-->2 lines of H13CN, HC15N, and HNC. The N=2-->1 transition of CN near 226 GHz was also detected, and an upper limit was obtained for the J=2-->1 line of HCNH+. From the measurements, column densities and production rates have been estimated. A column density ratio of [HCN]/[HNC] = 7+/-1 was observed near perihelion, while it was found that [HCN]/[HCNH+] greater, similar 1. The production rates at perihelion for HCN and CN were estimated to be Q(HCN) approximately 1x1028 s-1 and Q(CN) approximately 2.6x1027 s-1, respectively, resulting in a ratio of [HCN]/[CN] approximately 3. Consequently, HCN is sufficiently abundant to be the parent molecule of CN in Hale-Bopp, and HCNH+ could be a source of HNC. Finally, carbon and nitrogen isotope ratios of 12C/13C = 109+/-22 and 14N/15N = 330+/-98 were obtained from HCN measurements, in agreement with previous values obtained from J=4-->3 data. Such ratios suggest that comet Hale-Bopp formed coevally with the solar system.