Basin‐scale fluvial correlation and response to the Tethyan marine transgression: An example from the Triassic of central Spain     

Maximilian Franzel  Stuart J. Jones  Neil Meadows  Mark B. Allen  Ken McCaffrey  Tim Morgan 《Basin Research》2021,33(1):1-25

The relationships between large‐scale depositional processes and the stratigraphic record of alluvial systems, e.g. the origin and distribution of channel stacking patterns, changing architecture and correlation of strata, are still relatively poorly understood, in contrast to marine systems. We present a study of the Castillian Branch of the Permo‐Triassic Central Iberian Basin, north‐eastern Spain, using chemostratigraphy and a detailed sedimentological analysis to correlate the synrift Triassic fluvial sandstones for ~80 km along the south‐eastern basin margin. This study investigates the effects of Middle Triassic (Ladinian) Tethyan marine transgression on fluvial facies and architecture. Chemostratigraphy identifies a major, single axially flowing fluvial system lasting from the Early to Middle Triassic (~10 Ma). The fluvial architecture comprises basal conglomerates, followed by amalgamated sandstones and topped by floodplain‐isolated single‐ or multi‐storey amalgamated sandstone complexes with a total thickness up to ~1 km. The Tethyan marine transgression advanced into the basin with a rate of 0.04–0.02 m/year, and is recorded by a transition from the fluvial succession to a series of maximum flooding surfaces characterised by marginal marine clastic sediments and sabkha evaporites. The continued, transgression led to widespread thick carbonate deposition infilling the basin and recording the final stage of synrift to early‐post‐rift deposition. We identify the nonmarine to marine transition characterised by significant changes in the Buntsandstein succession with a transition from a predominantly tectonic‐ to a climatically driven fluvial system. The results have important implications for the temporal and spatial prediction of fluvial architecture and their transition during a marine transgression.  相似文献   

The new “Silk Road Economic Belt” as a threat to the sustainable management of Central Asia’s transboundary water resources   总被引：1，自引：0，他引：1  

Ken W. F. Howard  Karina K. Howard 《Environmental Earth Sciences》2016,75(11):976

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The International Association of Hydrogeologists (IAH): reflecting on 60 years of contributions to groundwater science and water management   总被引：2，自引：0，他引：2  

Willi Struckmeier  Ken Howard  John Chilton 《Hydrogeology Journal》2016,24(5):1069-1086

The 60th anniversary of the founding of the International Association of Hydrogeologists (IAH) is an important milestone that allows pause for reflection on how the association has evolved over the years and the contributions it has made to groundwater science and water management. IAH was founded in 1956 at the 20th International Geological Congress and developed rapidly during the 1980s and 1990s in response to a growing global interest in groundwater mapping and in sound approaches to resource protection and sustainable aquifer management. Incorporated in 2000, IAH has now secured its position as the world’s leading international association specialising in groundwater with over 4,100 members in 131 countries. Much credit for this success must go to members, past and present, whose individual efforts and collaboration with sister institutions are documented here. These members have shaped the association’s goals and contributed selflessly to its scientific programmes, publications and educational and charitable activities. Looking ahead to the next 60 years, it is essential that IAH does not rest on past achievements but listens and adjusts to the needs of members while continuing to pursue its mission of furthering the understanding, wise use and protection of groundwater resources throughout the world.  相似文献   

Lessons from the 2003 Tokachi-oki, Japan, earthquake for prediction of long-period strong ground motions and sloshing damage to oil storage tanks   总被引：1，自引：0，他引：1  

Ken Hatayama 《Journal of Seismology》2008,12(2):255-263

The 2003 Tokachi-oki earthquake (M _w 8.0) in northern Japan generated large-amplitude long-period (4–8 s) ground motions in the Yufutsu sedimentary basin, causing severe damage to seven large oil storage tanks with floating roof structures because of severe sloshing of oil. The 30,000–40,000-m³ tanks having suffered the severe damage such as fires and sinking of floating roofs experienced the sloshing with large amplitudes exceeding 3 m in which the fundamental mode was predominant. The second mode of sloshing was also excited in the 110,000-m³ tanks in which their floating roofs sank into oil, indicating that the higher modes of sloshing as well as the fundamental mode should be considered in damage prediction. The strong ground motion recordings demonstrated the earthquake dependency of predominant periods and the substantial spatial variation of the long-period shaking observed within the Yufutsu basin, meaning the necessity of source- and site-specific prediction of long-period strong ground motions. The two-dimensional numerical modeling suggested the importance of detailed structures of soft near-surface sediments as well as deep basin structure for accurate prediction of long-period strong ground motions in deep sedimentary basins.  相似文献   

Dr Woodward's 350‐year legacy          下载免费PDF全文

Ken McNamara 《Geology Today》2015,31(5):181-186

Almost three hundred and fifty years ago, on 1 May 1667, in Draycott, Derbyshire, northern England, John Woodward was born. Although we know precious little about his early life, he left a legacy that has resonated down the centuries. In a letter written in 1723 to a physician friend, John Allen of Bridgewater, five years before he died, Woodward confided that ‘I have bequeathd … an Hundred & Fifty Pounds per annum to the University of Cambridge, which I intreat [sic] you to keep secret …’  相似文献   

Atmospheric impacts of sea ice decline in CO2 induced global warming     

Ivana Cvijanovic  Ken Caldeira 《Climate Dynamics》2015,44(5-6):1173-1186

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Mesoscale decrease of surface phosphate and associated phytoplankton dynamics in the vicinity of the subtropical South Pacific islands     

Fuminori Hashihama  Mitsuhide Sato  Shigenobu Takeda  Jota Kanda  Ken Furuya 《Deep Sea Research Part I: Oceanographic Research Papers》2010,57(3):338-350

Surface distributions of nutrients and phytoplankton were investigated in the vicinity of the subtropical South Pacific islands by using a continuous underway system with a highly sensitive nutrient analysis. A total of 17 transects, whose lengths ranged between 42 and 271 km, were sampled for continuous nutrient measurements. The study area was characterized by an overall depletion of nitrate+nitrite (<15 nM), but phosphate varied from 7 to 192 nM. The transects were grouped into 4 patterns according to distribution of phosphate concentrations. In 7 transects, a mesoscale decrease in phosphate occurred, coinciding with an elevation of in vivo chlorophyll fluorescence, which was accompanied by an increase in phytoplankton abundance as revealed by microscopy, flow cytometry, and accessory pigments. This mirror–image relationship between the phosphate concentration and phytoplankton abundance was most apparent on both a 99-km transect east of Tonga, where the phosphate concentration ranged from 17 to 125 nM, and on a 98-km transect west of Fiji, where the phosphate concentration ranged from 23 to 136 nM. Both these transects contained distinct blooms of Trichodesmium in areas with the lowest concentrations of phosphate. In other 2 transects, fluctuations in phosphate concentrations showed no distinct relationship with chlorophyll fluorescence. Other patterns that emerged included consistently high concentrations, ranging from 109 to 192 nM, in 5 transects and consistently low phosphate concentrations, ranging from 7 to 50 nM, in 3 transects. Abundance of Trichodesmium, Prochlorococcus, Synechococcus, and all accessory pigments examined tended to be higher in the low phosphate transects than in the high phosphate ones. In particular, Trichodesmium occurred in low phosphate water (<25 nM). There was no significant relationship between phosphate concentrations and nanoplanktonic unicellular cyanobacteria. Our observations suggest that surface phosphate decreases are associated with phytoplankton utilization of phosphate, and that nitrogen supply from Trichodesmium may contributes to this utilization.  相似文献   

Preface     

Monica Pondrelli  Ken Tanaka  Angelo Pio Rossi  Enrico Flamini 《Planetary and Space Science》2011,59(11-12):1113

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Gamma-Ray Bursts and magnetar-forming Supernovae     

Ken’ichi Nomoto  Keiichi Maeda  Masaomi Tanaka  Tomoharu Suzuki 《Astrophysics and Space Science》2011,336(1):129-137

The connection between long Gamma Ray Bursts (GRBs) and Supernovae (SNe) have been established through the well observed cases. These events can be explained as the prompt collapse to a black hole (BH) of the core of a massive star (M≳40M _⊙). The energies of these GRB-SNe were much larger than those of typical SNe, thus these SNe are called Hypernovae (HNe). The case of SN 2006aj/GRB060218 appears different: the GRB was weak and soft, being called an X-Ray Flash (XRF); the SN is dimmer and has very weak oxygen lines. The explosion energy of SN 2006aj was smaller, as was the ejected mass. In our model, the progenitor star had a smaller mass than other GRB-SNe (M∼20M _⊙), suggesting that a neutron star (NS) rather than a BH was formed. If the nascent NS was strongly magnetized as a magnetar and rapidly spinning, it may launch a weak GRB or an XRF. The peculiar light curve of Type Ib SN 2005bf may also be powered by a magnetar. The blue-shifted nebular emission lines of 2005bf indicate the unipolar explosion possibly related to standing accretion shock instability (SASI) associated with a newly born NS.  相似文献   

Numerical analysis of soil pipe effects on hillslope water dynamics     

Raj H. Sharma  Heinz Konietzky  Ken’ichirou Kosugi 《Acta Geotechnica》2010,5(1):33-42

Soil pipes are considered to drain off water from a hillslope and play an important role in the subsurface runoff generation process, thus reducing the slope failure susceptibility. However, soil pipes are also often detected on the collapsed slope suggesting that they might act to induce slope instability. To examine how the soil pipes act on pore-water pressure generation and on a slope failure processes, a numerical model was developed. The model was used to test the response of pore-water pressure in a hillslope with soil pipes of different cross-sectional areas, lengths, distances from the impermeable bed, roughness, and hillslope angles. The model was also tested to find the response of open soil pipe if blocked. The study reveals that pipes reduce pore-water pressure (measured closed to bed) around its upstream end and increase around its downstream end if compared with no pipe case. Pore-water pressure at downstream end is increased with increase in hillslope angle, pipe cross-sectional area, pipe length, or depth of soil pipe. Soil pipe, even if it is ended within the hillslope, increases the total discharge from hillslope. Location of rough soil also affects the discharge and pressure within the hillslope. If the less rough pipe is close to the source of water, discharge from hillslope matrix is greater regardless of its downstream pipe roughness. Blockage of small portion of open soil pipe increases the soil pressure around the region but not beyond the case if there is no soil pipe. However, complete collapse of soil pipe from a point to all along the downstream end of hillslope increases the pore-water pressure beyond the pressure if there were no soil pipes. Therefore, the position and type of soil pipe collapse might play an important role in shallow landslide initiation.  相似文献