Fresh-Water/Sea-Water Relationship Within a Ground-Water Flow System, Northeastern Coast of the Yucatan Peninsula   总被引：7，自引：0，他引：7  

Yolanda H. Moore  Ronald K. Stoessell  Dale H. Easley 《Ground water》1992,30(3):343-350

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Sr-Isotope record of Quaternary marine terraces on the California coast and off Hawaii     

Kenneth R. Ludwig  Daniel R. Muhs  Kathleen R. Simmons  James G. Moore 《Quaternary Research》1992,37(3)

Strontium-isotopic ratios of dated corals have been obtained from submerged reefs formed during Quaternary glacial periods off the Hawaiian islands. These data, combined with data from deep-sea sediments, tightly constrain the secular variation of marine ⁸⁷Sr/⁸⁶Sr for the past 800,000 yr. Although long-term trends are apparent, no significant (>0.02‰), rapid (<100,000 yr) excursions in ⁸⁷Sr/⁸⁶Sr were resolved nor did we observe any samples with ⁸⁷Sr/⁸⁶Sr greater than that of modern seawater. Strontium in mollusks from elevated marine terraces formed during interglacial periods on the southern California coast show resolvable and consistent variations in ⁸⁷Sr/⁸⁶Sr which, when compared to the trend of Quaternary marine ⁸⁷Sr/⁸⁶Sr, can be used to infer uplift rates and define approximate ages for the higher terraces. The Sr-isotope age estimates indicate that uplift rates vary among crustal blocks and were not necessarily constant with time. No contrast in Sr-isotopic ratios between similar-age Hawaiian and California fossils was observed, confirming that any change in marine ⁸⁷Sr/⁸⁶Sr from glacial to interglacial periods must be small. A realistic appraisal of the potential of Sr-isotope stratigraphy for chronometric applications in the Quaternary suggests that the technique will be limited to relatively coarse distinctions in age.  相似文献   

Preface     

Thomas D. Demchuk  Jane C. Shearer  Timothy A. Moore 《International Journal of Coal Geology》1995,28(2-4)

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Nuées Ardentes of the 1968 Eruption of Mayon Volcano,Philippines     

J. G. Moore  W. G. Melson 《Bulletin of Volcanology》1969,33(2):600-620

Mayon Volcano, southeastern Luzon, began a series of explosive eruptions at 0900 April 21, 1968, and by May 15 more than 100 explosions had occurred, at least 6 people had been killed, and roughly 100 square km had been covered by more than 5 cm of airfall ash, blocky ash flows, and a lava flow. All material crupted was porphyritic augite-hypersthene andesite. Explosions from the summit crater (elevation 2460 m) ejected large quantities of ash and incandescent blocks to a height exceeding 600 m and produced ash-laden clouds which rose to heights of 3 to 10 km. Backfall of the coarser material fed nuées ardentes which repeatedly swept down ravines on all sides of the volcanic cone. The velocity of one nuée ardente ranged from 9 to 63 m per sec. The largest nuées descended to the southwest and reached as far as 7 km from the summit. An aa lava flow also descended 3 1/2 km down this flank. The nuées ardentes deposited pyroclastic flows that contained large breadcrust-surfaced blocks averaging about 30 cm across, but occasionally reaching 25 m in greatest dimension. These blocks were still very hot in their interiors several days later. Surrounding the pyroclastic flows is a seared zone as much as 2 km wide, but averaging a few hundred meters, in which vegetation is charred and splintered, but over which only a thin layer of airfall ash was deposited.  相似文献   

Variable carbon contents of lunar soil 74220     

Everett K. Gibson Jr.  Carleton B. Moore 《Earth and Planetary Science Letters》1973,20(3):404-408

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Noble gas and carbon abundances of the Haverö, Dingo Pup Donga,and North Haig ureilites     

D.D. Bogard  E.K. Gibson  D.R. Moore  N.L. Turner  R.B. Wilkin 《Geochimica et cosmochimica acta》1973,37(3):547-557

Total carbon determinations on the Haverö, Dingo Pup Donga, and North Haig ureilites yield values of 2.07, 3.17, and 5.58 wt.%, respectively. Haverö and Dingo Pup Donga contain relatively large amounts of trapped Ar, Kr and Xe, which like the carbon content varies with grain size for Haverö. These two meteorites also contain dominant cosmic rayproduced He and Ne, and show ³He exposure ages of ~23 m.y. and ~7 m.y., respectively. North Haig contains much smaller amounts of trapped gases and spallogenic gases, which may result from loss due to terrestrial weathering. The isotopic composition of Xe in five grain size analyses of Haverö and a whole rock analysis of Dingo Pup Donga shows the presence of a major solar-like Xe component. The presence of this solar component adds an additional complication to the concept of forming ureilites from carbonaceous chondrites.  相似文献   

Late Pleistocene-Holocene oceanographic changes in the Northeastern Pacific     

Ted C. Moore 《Quaternary Research》1973,3(1):99-109

The distributions of the radiolarian assemblages in the Northeastern Pacific Ocean were determined and correlated with the average summer temperature of the near surface waters of this region. These assemblages were compared with those in three sediment cores taken beneath the Transition Zone waters. This comparison indicates that the assemblage off Oregon at the last maximum cold interval (24,000 yr B.P.) was like that now found off southern Alaska. The correlation of the radiolarian assemblages with temperature gives an estimate of 11°C for the average summer temperature at that time. This is approximately 4°C cooler than present day conditions in the area. Superimposed on the general warming trend that began 24,000 y.a., there are minor oscillations in the assemblages which correspond to estimates of temperature change of about 2°C in the Pleistocene and about 1°C in the Holocene. In the Holocene, these minor warm intervals appear to be approximately synchronous with advances in mountain glaciers.  相似文献   

The impact of seasonality on multi-scale feature extraction techniques     

Brian Moore  Jacob J. McKee 《International Journal of Digital Earth》2020,13(1):9-21

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Short gravity and capillary wave spectra from tower-based radar     

Lawner  R. Moore  R. 《Oceanic Engineering, IEEE Journal of》1984,9(5):317-324

Radar backscatter measurements made as part of Project MARSEN in 1979 from the Noordwijk tower off the Dutch coast are used to calculate apparent ripple (capillary and short-gravity wave) spectra by inverting the small-perturbation scattering theory. The measurements were made at 10 and 15 GHz for angles of incidence ranging from20degto70deg; this means that the range of Bragg-resonant spatial wavenumbers covered is from 1.43 to 5.90 cm^-1. Results of coincidentC- andX-band experiments by the Institute Francais du Petrole (IFP) andX-band experiments by a group of Dutch researchers (TNO) are compared with our results and good general agreement is found. Our initial results show a steeper falloff of the spectra with increasing wavenumber than reported previously, particularly at low windspeeds. When the spectra are modified to account for the difference between previous aircraft and tower measurements [1], the observed spectra agree well with the appropriate part of Pierson's wave spectrum as modified by Fung and Lee [2].  相似文献   

THE WILLOWBAR METEORITE*     

David E. Lange  Carleton B. Moore  Kendall Rhoton 《Meteoritics & planetary science》1973,8(3):263-275

The Willowbar, Oklahoma meteorite was found by Kendall Rhoton in December, 1971, lat 36° 44′ N.; long 102° 12′ W. It is a shocked brecciated L6 chondrite (Fa-24.3) with large black veins cutting areas of normal chondritic texture. It weighed 2.07 kg.  相似文献