Platform-basin transitions and their role in Alpine-style collision systems: a comparative approach     

Cameron Bell  Robert W. H. Butler 《Swiss Journal of Geoscience》2017,110(2):535-546

The structure of Alpine-type orogenic belts is widely assumed to have been strongly influenced by the inherited structure of the rifted continental margins from which they were formed. The challenge lies in deciphering these influences when orogenic contraction is strong. Contractional deformation in the Kamchia basin (SW Black Sea), caught between the Balkan orogenic belt and the stable Moesian block, has been arrested, preserving the early development of an Alpine-type orogen. We use 3D seismic and well-data to examine the tectonic and stratigraphic structure of this basin. Significant deformation has occurred underwater, through inversion tectonics within the basin itself. However, the basin margin structures have not reactivated. This margin is marked by a low-angle unconformity across which sediment was routed from the platform into the fledgling syn-orogenic basins. Such pathways may explain non-orogen-derived sediment within parts of the ancestral Apennine foredeep, for example. The role of platform margins to focus contractional deformation may have been over-emphasised elsewhere in the Alpine system. Further, the more strongly subsided portions of rifted margins may have accommodated significant contractional deformation through reactivation of basin faults. In the western Alps the complexity of structural juxapositions across thrust sheets in the Brianconnais may reflect these early-orogenic deformations rather than be the product of deformation that happened after tectonic burial. These early deformations are likely to be recorded in early syn-tectonic depositional sequences.  相似文献   

Towards a real‐time transient classification engine     

J.S. Bloom  D.L. Starr  N.R. Butler  P. Nugent  M. Rischard  D. Eads  D. Poznanski 《Astronomische Nachrichten》2008,329(3):284-287

Temporal sampling does more than add another axis to the vector of observables. Instead, under the recognition that how objects change (and move) in time speaks directly to the physics underlying astronomical phenomena, next‐generation wide‐field synoptic surveys are poised to revolutionize our understanding of just about anything that goes bump in the night (which is just about everything at some level). Still, even the most ambitious surveys will require targeted spectroscopic follow‐up to fill in the physical details of newly discovered transients. We are now building a new system intended to ingest and classify transient phenomena in near real‐time from high‐throughput imaging data streams. Described herein, the Transient Classification Project at Berkeley will be making use of classification techniques operating on “features” extracted from time series and contextual (static) information. We also highlight the need for a community adoption of a standard representation of astronomical time series data (ie. “VOTimeseries”). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

Seismic precursors to a 2017 Nuugaatsiaq,Greenland, earthquake–landslide–tsunami event     

Butler  Rhett 《Natural Hazards》2019,96(2):961-973

High-frequency (5–20 Hz) seismic signals precursory to and embedded within the June 17, 2017 M_L?=?4 earthquake–landslide event are analyzed. This event in western Greenland generated a tsunami in Karrat fjord inundating Nuugaatsiaq village 32 km distant. Spectrogram and wavelet analyses of seismic data from the Greenland Ice Sheet Monitoring Network (GLISN) corroborate observations of seismic precursors at Nuugaatsiaq reported by Poli (Geophys Res Lett 44:8832–8836, 2017) and Caplan-Auerbach (in: AGU fall meeting abstracts, 2017) and reveal additional high-frequency arrivals being generated after the apparent initiation of fault rupture. New observations of seismic precursors 181 km from the Event at Upernavik, Greenland are correlated with those seen at Nuugaatsiaq. Wavelet analysis presents?>?100 significant energy peaks accelerating up to and into the earthquake–landslide event. The precursor events show a distinct, power law distribution, characterized by b values of ~?2.4. Results are compared and contrasted with small precursors observed in the studies of a natural chalk cliff landslide at Mesnil-Val, Haute Normandie, France. The earthquake–landslide appears to have been initiated by seismic precursors located at the fault scarp, leading to a small seismic foreshock and small landslide initiation, followed by a larger earthquake at the fault scarp, precipitating the primary landslide into the Karrat Fjord, which caused the subsequent tsunami.

  相似文献   

Solar system science with SKA     

B.J. Butler  D.B. Campbell  I. de Pater  D.E. Gary 《New Astronomy Reviews》2004,48(11-12):1511

Radio wavelength observations of solar system bodies reveal unique information about them, as they probe to regions inaccessible by nearly all other remote sensing techniques and wavelengths. As such, the SKA will be an important telescope for planetary science studies. With its sensitivity, spatial resolution, and spectral flexibility and resolution, it will be used extensively in planetary studies. It will make significant advances possible in studies of the deep atmospheres, magnetospheres and rings of the giant planets, atmospheres, surfaces, and subsurfaces of the terrestrial planets, and properties of small bodies, including comets, asteroids, and KBOs. Further, it will allow unique studies of the Sun. Finally, it will allow for both indirect and direct observations of extrasolar giant planets.  相似文献   

Analysis of slug tests in formations of high hydraulic conductivity   总被引：1，自引：0，他引：1  

Butler JJ  Garnett EJ  Healey JM 《Ground water》2003,41(5):620-631

A new procedure is presented for the analysis of slug tests performed in partially penetrating wells in formations of high hydraulic conductivity. This approach is a simple, spreadsheet-based implementation of existing models that can be used for analysis of tests from confined or unconfined aquifers. Field examples of tests exhibiting oscillatory and nonoscillatory behavior are used to illustrate the procedure and to compare results with estimates obtained using alternative approaches. The procedure is considerably simpler than recently proposed methods for this hydrogeologic setting. Although the simplifications required by the approach can introduce error into hydraulic-conductivity estimates, this additional error becomes negligible when appropriate measures are taken in the field. These measures are summarized in a set of practical field guidelines for slug tests in highly permeable aquifers.  相似文献   

Has the amount of tar on the open ocean changed in the past decade?     

Anthony H Knap  Thomas M Iliffe  James N Butler 《Marine pollution bulletin》1980,11(6):161-164

Quantitative surveys of beach tar on Bermuda during 1978–1979 are compared with similar surveys in 1971–1972. A 15% increase in the mean, while not significantly different from previously observed levels, is significantly higher than the reported 27% decrease due to improvements in tanker operations.  相似文献   

Occurrence of negative open variances in ternary systems     

John C. Butler 《Mathematical Geosciences》1975,7(1):31-45

Parameters of the hypothetical open arrays were computed for a total of 20 published sets of chemical analyses of igneous rocks in oxide, mole, cation, and cation weight-percentage forms. Negative open variances in the full (11 variables) data sets were eliminated by using a linear transformation of the raw data. For the 13 variables (11 oxides, the sum of the alkalies and total iron as FeO) 286 different simple ternary combinations can be formed. The CaO-Na₂O-K₂O (CNK) and total iron-serum of the alkalies-MgO (FMA) combinations are of frequent use in depicting “differentiation trends” within a series of igneous rocks. In each of the 20 data sets the estimated open variances of Na₂O in the CNK and total iron in the FMA combinations are negative. Elimination of negative open variances in the full data array does not eliminate negative open variances in these ternary combinations. Greater than 50 percent of the 29,172 ternary combinations examined contain a negative open variance.  相似文献   

The dissection and consortium allocation of Apollo 17 lunar rocks from the boulder at station 7     

P. Butler  T.E. Dealing 《Earth and Planetary Science Letters》1974,23(3):429-434

The Apollo 17 astronauts removed four rocks samples to represent each of the lithologies they recognized in the boulder at station 7: sample 77215 from an off-white meter-sized block; sample 77075 from one of the thin dikes that cross the off-white block; 77115 from the blue-gray rock adjacent to the off-white block and apparently continuous with thin dikes that cross the block; sample 77135 of the tan-gray or green-gray vesicular rock adjacent to the blue-gray (77115) rock. A consortium of investigators has been organized, under the leadership of E.C.T. Chao, to study the samples. Each sample shows a number of lithologic types in terms of clasts (or xenoliths) and matrices. A table shows how subsamples have been allocated for consortium study. Maps and photographs show the relations between subsample locations and lithologies for the two more dissected samples, 77115 and 77135.  相似文献   

Atmospheric ion wakes of Venus and Mars in the solar wind     

P.A. Cloutier  R.E. Daniell  D.M. Butler 《Planetary and Space Science》1974,22(6):967-990

A model has been developed for the currents induced in the ionospheres of Venus and Mars by the flowing magnetized solar wind in a previous paper (Cloutier and Daniell, 1973). The altitudes of the ionopauses on both planets, determined from the electrodynamical models of the previous paper, are used here to calculate the total rates of atmospheric mass loss to the solar wind for Venus and Mars. These loss rates are compared to the rates calculated by Michel (1971) based upon the limit of mass loading of the solar wind flow determined from hydrodynamic constraints. The distributions of planetary ions in the downstream wakes of Venus and Mars are calculated, and the interpretation of ion spectrometer measurements from close planetary encounters is discussed.  相似文献   

A simple correction for slug tests in small-diameter wells   总被引：2，自引：0，他引：2  

Butler JJ 《Ground water》2002,40(3):303-308

A simple procedure is presented for correcting hydraulic conductivity (K) estimates obtained from slug tests performed in small-diameter installations screened in highly permeable aquifers. Previously reported discrepancies between results from slug tests in small-diameter installations and those from tests in nearby larger-diameter wells are primarily a product of frictional losses within the small-diameter pipe. These frictional losses are readily incorporated into existing models for slug tests in high-K aquifers, which then serve as the basis of a straightforward procedure for correcting previously obtained K estimates. A demonstration of the proposed procedure using data from a series of slug tests performed in a controlled field setting confirms the validity of the approach. The results of this demonstration also reveal the detailed view of spatial variations in K that can be obtained using slug tests in small-diameter installations.  相似文献