The Romanian earthquake of August 30, 1986: A study based on GEOSCOPE very long-period and broadband data     

Tony Monfret  Anne Deschamps  Barbara Romanowicz 《Pure and Applied Geophysics》1990,133(2):367-379

The Romanian earthquake of August 30, 1986 is the second largest intermediate depth event in this area since the worldwide deployment of digital instrumentation, and the first one since the installation of GEOSCOPE network. It offers the unique opportunity to document this well-known but poorly understood zone of deep continental seismicity using high quality teleseismic data in different frequency bands. The source is well constrained both from very-long period surface wave data observed on GEOSCOPE stations and, independently, from body wave modelling at various worldwide stations. The depth obtained is approximately 140 kilometers, the seismic moment, 0.8 10²⁷ dyne-cm and the mechanism from both data sets is very similar to that of the previous 1940 and 1977 Vancrea events, indicating that these events, although having occurred at noticeably different depths, are expressions of the same tectonic process. However, from the detailed study of the source using broadband data, it can be inferred that the source presents much less complexity than the 1977 event.  相似文献   

Hydrogeological Decision Analysis: 1. A Framework   总被引：6，自引：0，他引：6  

R. Allan Freeze  Joel Massmann  Leslie Smith  Tony Sperling  Bruce James 《Ground water》1990,28(5):738-766

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Geochemistry of the Siberian Trap of the Noril'sk area,USSR, with implications for the relative contributions of crust and mantle to flood basalt magmatism   总被引：6，自引：1，他引：6  

P. C. Lightfoot  A. J. Naldrett  N. S. Gorbachev  W. Doherty  V. A. Fedorenko 《Contributions to Mineralogy and Petrology》1990,104(6):631-644

The sequence investigated of the Siberian Trap at Noril'sk, USSR, consists of at least 45 flows that have been divided into six lava suites. The lower three suites consist of alkalic to subalkalic basalts (the Ivakinsky suite), overlain by nonporphyritic basalts (the Syverminsky suite), and porphyritic and picritic basalts (the Gudchikhinsky suite). The upper three suites are tholeiitic. The uppermost 750 m of dominantly non-porphyritic basalt belong to the Mokulaevsky suite and are characterized by a nearly constant Mg number (0.54–0.56), SiO₂ (48.2–49.1 wt%), Ce (12–18 ppm), and Ce/Yb (5–8). The underlying 1100 m of dominantly porphyritic basalt belong to the Morongovsky and Nadezhdinsky suites. There is a continuous increase in SiO₂ (48.1–55.2 wt%), Ce (12–41 ppm), and Ce/Yb (5–18) from the top of the Mokulaevsky to the base of the Nadezhdinsky with little change in the Mg number (0.53–0.59). Mokulaevsky magmas have trace element signatures similar to slightly contaminated transitional type mid-ocean ridge basalts. The change in major and trace element geochemistry in the upper three suites is consistent with a decline in the degree of anatexis and assimilation of tonalitic upper crust by Mokulaevsky magma. The Nadezhdinsky and underlaying lavas thicken within and thus appear to be related to an elongate basin centred on the Noril'sk-Talnakh mining camp. The Mokulaevsky and Morongovsky lavas thicken to the east and appear to be related to a basin centred more than 100 km to the east of the Noril'sk region; these magmas may have risen up out of a different conduit system.  相似文献   

Neutralizing Homelessness, 2015: Tent cities and ten year plans     

Tony Sparks 《Urban geography》2017,38(3):348-356

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Distinguished Service Award: Anna Susan Michelle Wilson          下载免费PDF全文

Tony Binns 《New Zealand geographer》2018,74(1):59-59

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Malham Cove: splendour and enigma          下载免费PDF全文

Tony Waltham 《Geology Today》2017,33(1):32-40

A dry waterfall that recently came to life, a landform that is not karstic in the middle of a great karst terrain, underground drainage that is not as simple as it seems, and on‐going debate about how it was formed: Malham Cove is more than just a spectacular sight.  相似文献   

Lötschberg–geology for tunnellers     

Tony Waltham 《Geology Today》2007,23(3):101-107

Switzerland's Lötschberg tunnels present a long story of both failure and success. Tunnelling that began 100 years ago ended in a massive disaster–which is a classic of engineering geology–but subsequent works were very much more successful.  相似文献   

Millennial-scale sea-level control on avulsion events on the Amazon Fan     

Mark Maslin  Paul C. Knutz  Tony Ramsay 《Quaternary Science Reviews》2006,25(23-24):3338

The Late Quaternary Amazon deep-sea fan provides a modern analogue to ancient fan systems containing coarse-grained hydrocarbon reservoirs. Sand lenses deposited within the Amazon Fan, due to abrupt shifts in channel pathways called avulsion events, were drilled as part of ODP Leg 155. The hemipelagic sediment directly on top of the avulsion sands was dated using primarily AMS radio carbon dating. This dating shows that these large sand lobes (1 km³) are triggered by relatively small, millennial scale changes in marine transgression and regression (±5–10 m). Relative sea level also controls the architecture of the Channel–levee distributive systems within the Amazon Fan. For example prior to 22 k calendar years BP there is a tripartite channel system. After 22 ka there is only one active Channel–levee system. Transitions between the multi-channel and single channel configurations are related to variations in the volume of sediment supply resulting in aggradation or erosion of channel floor and levee growth in the canyon-channel transition area. The sensitivity of the Amazon deep-sea Fan sedimentation to relatively small changes in sea level supports one of the central assumptions of the theory of Sequence Stratigraphy. In addition this study demonstrates how traps for hydrocarbons may have been formed in ancient fan systems.  相似文献   

Old stellar population synthesis: new age and mass estimates for Mayall Ⅱ = G1     

Jun Ma  Richard de Grijs  Zhou Fan  Soo-Chang Rey  Zhen-Yu Wu  Xu Zhou  Jiang-Hua Wu  Zhao-Ji Jiang  Jian-Sheng Chen  Kyungsook Lee  Sangmo Tony Sohn 《中国天文和天体物理学报》2009,9(6)

Mayall Ⅱ = G1 is one of the most luminous globular clusters (GCs) in M31. Here, we determine its age and mass by comparing multicolor photometry with theo-retical stellar population synthesis models. Based on far- and near-ultraviolet GALEX photometry, broad-band UBV RI, and infrared JHK8 2MASS data, we construct the most extensive spectral energy distribution of G1 to date, spanning the wavelength range from 1538 to 20000A. A quantitative comparison with a variety of simple stellar pop-ulation (SSP) models yields a mean age which is consistent with G1 being among the oldest building blocks of M31 and having formed within ～1.7Gyr after the Big Bang. Irrespective of the SSP model or stellar initial mass function adopted, the resulting mass estimates (of order 107M⊙) indicate that G1 is one of the most massive GCs in the Local Group. However, we speculate that the cluster's exceptionally high mass suggests that it may not be a genuine GC. Our results also suggest that G1 may contain, on average, (1.65±0.63) × 102L⊙ far-ultraviolet-bright, hot, extreme horizontal-branch stars, depend-ing on the adopted SSP model. In addition, we demonstrate that extensive multi-passband photometry coupled with SSP analysis enables one to obtain age estimates for old SSPs that have similar accuracies as those from integrated spectroscopy or resolved stellar pho-tometry, provided that some of the free parameters can be constrained independently.  相似文献   

An introduction to the South China Sea throughflow: Its dynamics, variability, and application for climate   总被引：9，自引：0，他引：9  

Tangdong Qu  Y. Tony Song  Toshio Yamagata 《Dynamics of Atmospheres and Oceans》2009,47(1-3):3

The South China Sea throughflow (SCSTF) involves the inflow through the Luzon strait and the outflow through the Karimata, Mindoro, and Taiwan straits. Recent studies have suggested that the SCSTF act as a heat and freshwater conveyor, playing a potentially important role in regulating the sea surface temperature pattern in the South China Sea and its adjoining tropical Indian and Pacific Oceans. In this introductory paper, we attempt to convey the progress that has recently been made in understanding the SCSTF. We first provide an overview of existing observations, theories, and simulations of the SCSTF. Then, we discuss its interaction with the Pacific western boundary current and Indonesian throughflow. Finally, we summarize issues and questions that remain to be addressed, with special reference to the SCSTF's dynamics, variability, and implication for climate.  相似文献