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Cascadia Convergent Zone: An Example of Primary Convergent Seismogenic Structure

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Open Journal of Earthquake Research 2019年第2期8卷 132-164页

作者： kenneth m. Cruikshank Curt d. Peterson department of Geology Portland State University Portland Oregon USA

In this article, a case is made for very-large or primary seismogenic structures in convergent margins, based on anomalous large earthquake magnitudes (mw 8 - 9) relative to rupture lengths. Out of 56,293 earthquakes (magnitudes ≥ 5) cataloged worldwide, the 10 largest events in transform, divergent, and interior settings average magnitudes of 7.3 - 7.6. But in convergent margins, the average magnitude of the 10 largest events is 8.5, roughly 32 times more energy than the other neotectonic settings. The large anomalous magnitudes of energy release in convergent margins are attributed to the transfer of inter-plate stress to the upper-plate, where convergent elastic strain is accumulated during interseismic intervals. The large volumes of rock that accumulate the elastic strain in the upper-plates of convergent zones are defined here as primary seismogenic structures. Several datasets of 1) modern upper-plate convergent strain, 2) historical earthquakes, 3) modern upper-plate vertical displacements, and 4) recent inter-plate events of Episodic Tremor and Slip (ETS) are compared to establish the extent of the primary seismogenic structure in the Cascadia convergent zone. The across-margin extents of 1) significant convergent strain, 2) margin-parallel bands of vertical displacement, 3) historical seismicity and 4) ETS events, representing inter-plate coupling and shear stress transfer to strain accumulation in the upper-plate, are used to map the width of the primary seismogenic structure. The across-margin width of the primary seismogenic structure in the central Cascadia margin ranges from 300 km in the south-central margin to 450 km in the north-central margin, as mapped landward from the buried trench. A broad source region of coseismic energy release in the Cascadia primary seismogenic structure (300 - 450 km width) could yield stronger shaking in interior metropolitan centers from a future major rupture of the mega-thrust than has been modeled from a narrow “loc

关键词： Subduction Zone Crustal Structure Seismicity Strain deformation

Late Stage Interseismic Strain Interval, Cascadia Subduction Zone margin, USA and Canada

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Open Journal of Earthquake Research 2017年第1期6卷 1-34页

作者： kenneth m. Cruikshank Curt d. Peterson department of Geology Portland State University Portland OR USA

modern horizontal strain (2006-2016) measured along 56 new and 108 previously published GPS station baselines are used to establish the length (800 km) and width (300 - 400 km) of the central Cascadia convergent margin seismogenic structure. Across-margin (west-east) annual rates of shortening range from 10﹣9 a﹣1 at the eastern (landward) limit of the central Cascadia seismogenic structure to 10﹣7 a﹣1 along the western onshore portion of the interplate zone. Relatively high shortening strain rates (10﹣8 a﹣1 to 10﹣7 a﹣1) are also measured in western transects from the northern (Explorer plate) and southern (Gorda plate) segments of the convergent margin, demonstrating that the full length of the margin (1300 km length) is currently capable of sustaining and/or initiating a major great earthquake. Vertical GPS velocities are averaged over the last decade at 321 stations to map patterns of uplift (0 - 5 mm yr﹣1) and subsidence (0 - 9 mm yr﹣1) relative to the study area mean. Along-margin belts of relative uplift and subsidence, respectively, are approximately associated with Coast Ranges and the Cascade volcanic arc. However, the vertical velocity data are locally heterogeneous, demonstrating patchy “anomalies” within the larger along-margin belts. A large coastal subsidence anomaly occurs in southwest Washington where the modern short-term trend is reversed from the long-term (~200 yr) tidal marsh record of coastal uplift since the last co-seismic subsidence event (Ad1700). The modern vertical displacements represent a late stage of the current inter-seismic interval. If the horizontal strain is considered largely or fully elastic, extrapolating the modern strain rates over the last 100 years show the accumulated strains would be similar in magnitude to the observed co-seismic strains resulting from the Tōhoku, Japan, mw 9.0 earthquake in 2011. We believe that the central Cascadia seismogenic structure has accumulated sufficient elastic strain energy, during the last

关键词： Convergent margin Cascadia Strain Strain-Energy GPS

Strain Energy Release from the 2011 9.0 mw Tōhoku Earthquake, Japan

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Open Journal of Earthquake Research 2013年第4期2卷 75-83页

作者： kenneth m. Cruikshank Curt d. Peterson department of Geology Portland State University Portland USA

The purpose of this paper is to compare the strain energy released due to elastic rebound of the crust from the tragic 2011 9.0 mwTōhoku earthquake in Japan with the observed radiated seismic energy. The strain energy was calculated by analyzing coseismic displacements of 1024 GPS stations of the Japanese GEONET network. The value of energy released from the analysis is 1.75 × 1017J, which is of the same order of magnitude as the USGS-observed radiated seismic energy of 1.9 × 1017Nm (J). The strain energy method is independent of seismic methods for determining the energy released during a large earthquake. The analysis shows that although the energy release is concentrated in the epicentral region, about 12% of the total energy was released throughout the Japanese islands at distances greater than 500 km west of the epicenter. Our results also show that outside the epicentral region, the strainenergy was concentrated along known tectonic zones throughout Japan.

关键词： Japan Earthquake Crustal Strain GPS Radiated Energy

CT测量骨密度和肌肉质量可用于预测前列腺癌病人非癌性死亡

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国际医学放射学杂志 2017年第2期 220-221页

作者： A.m.mc donald T.A.Swain d.L.mayhew R.A.Cardan C.B.Baker d.m.harris 夏林 department of Radiation Oncology Hazelrig -Salter Radiation Oncology CenterUniversity of Alabama at Birmingham

摘要目的确定CT测量骨密度和肌肉质量能否提高局限性前列腺癌病人的非癌性死亡的预测性。材料与方法本研究已获得机构伦理委员会批准,免除病人的知情同意。纳

关键词：前列腺癌肌肉质量癌性死亡骨密度骨质密度病人 CT

Should patients with erectile dysfunction be evaluated for cardiovascular disease？

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Asian Journal of Andrology 2012年第1期14卷 138-144,179页

作者： kenneth A Ewane Hao-Cheng Lin Run Wang division of Urology University of Texas Medical School at Houston Houston TX 77030 USA department of Urology Affiliated Drum Tower Hospital Nanjing University School of Medicine Nanjing 210008 China department of Urology University of Texas M D Anderson Cancer Center Houston TX 77030 USA

The landmark massachusetts male Ageing Study shed new light on the prevalence of erectile dysfunction （Ed） and drew attention to Ed as a disease of ageing. Over the years, Ed has been linked to the development of cardiovascular disease （CVd） in some patients. There is clear evidence that Ed and CVd share and have a similar risk factor profile. CVd is one of the most recognizable causes of mortality and early detection coupled with prevention of mortality from CVd has been the prime interest of many researchers. Consequently, there has been a multidisciplinary curiosity regarding the proposal to use Ed as a marker for future CVd. I n fact, there have been several proposals to use Ed as a screening tool for future CVd. We performed a comprehensive Search of two main databases--Pubmed and Cochrane Library using a combination of keywords such as acute myocardial infarction, coronary artery disease （CAd） and Ed. Journal articles from January 2000 to June 2011 were reviewed. We included all articles discussing the relationship between Ed and CVd in the English language. All the relevant randomized controlled trials, cohort and retrospective studies, and review articles were included in our overall analysis in an attempt to answer the question whether all patients with Ed should be clinically evaluated for CVd. The results showed a link between Ed and the development of future CVd in some patients, but Ed was not shown to be an independent risk predictor that is any better than the traditional Framingham risk factors. Screening for CVd may, however, be rewarding in younger patients with severe Ed and in patients with concurrent CVd risk factors.

关键词： atherosclerotic disease cardiovascular disease coronary artery disease erectile dysfunction

The organization of societal conflicts by pavement ants Tetramorium caespitum： an agent-based model of amine-mediated decision making

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Current Zoology 2016年第3期62卷 277-284页

作者： Kevin m. HOOVER Andrew N. BUBAK Isaac J. LAW Jazmine d. W. YAEGER kenneth J. RENNER John G. SWALLOW michael J. GREENE department of Integrative Biology University of Colorado Denver Denver CO 80217-3364 USA Neuroscience Program University of Colorado Anschutz Medical Campus Aurora CO 80045 USA department of Biology University of South Dakota Vermillion South Dakota 57069 USA

Ant colonies self-organize to solve complex problems despite the simplicity of an individual ant＇s brain. Pavement ant Tetramorium caespitum colonies must solve the problem of defending the ter- ritory that they patrol in search of energetically rich forage. When members of 2 colonies randomly interact at the territory boundary a decision to fight occurs when： 1） there is a mismatch in nest- mate recognition cues and 2） each ant has a recent history of high interaction rates with nestmate ants. Instead of fighting, some ants will decide to recruit more workers from the nest to the fighting location, and in this way a positive feedback mediates the development of colony wide wars. In ants, the monoamines serotonin （5-HT） and octopamine （OA） modulate many behaviors associated with colony organization and in particular behaviors associated with nestmate recognition and ag- gression. In this article, we develop and explore an agent-based model that conceptualizes how in- dividual changes in brain concentrations of 5-HT and OA, paired with a simple threshold-based de- cision rule, can lead to the development of colony wide warfare. model simulations do lead to the development of warfare with 91% of ants fighting at the end of 1 h. When conducting a sensitivity analysis, we determined that uncertainty in monoamine concentration signal decay influences the behavior of the model more than uncertainty in the decision-making rule or density. We conclude that pavement ant behavior is consistent with the detection of interaction rate through a single timed interval rather than integration of multiple interactions.

关键词： agent-based model aggressive behavior ants decision making monoamines octopamine serotonin.

Engineered polycaprolactone–magnesium hybrid biodegradable porous scaffold for bone tissue engineering

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Progress in Natural Science:materials International 2014年第5期24卷 561-567页

作者： Hoi man Wong Paul K.Chu Frankie K.L.Leung kenneth m.C.Cheung Keith d.K.Luk Kelvin W.K.Yeung department of Orthopaedics and Traumatology The University of Hong Kong Shenzhen Key Laboratory for Innovative Technology in Orthopaedic Trauma The University of Hong Kong Shenzhen Hospital department of Physics and materials Science City University of Hong Kong Peking University Shenzhen Institution

In this paper, we describe the fabrication of a new biodegradable porous scaffold composed of polycaprolactone(PCL) and magnesium(mg)micro-particles. The compressive modulus of PCL porous scaffold was increased to at least 150% by incorporating 29% mg particles with the porosity of 74% using micro-CT analysis. Surprisingly, the compressive modulus of this scaffold was further increased to at least 236% when the silane-coupled mg particles were added. In terms of cell viability, the scaffold modified with mg particles significantly convinced the attachment and growth of osteoblasts as compared with the pure PCL scaffold. In addition, the hybrid scaffold was able to attract the formation of apatite layer over its surface after 7 days of immersion in normal culture medium, whereas it was not observed on the pure PCL scaffold. This in vitro result indicated the enhanced bioactivity of the modified scaffold. moreover, enhanced bone forming ability was also observed in the rat model after 3 months of implantation. Though bony in-growth was found in all the implanted scaffolds. High volume of new bone formation could be found in the mg/PCL hybrid scaffolds when compared to the pure PCL scaffold. Both pure PCL and mg/PCL hybrid scaffolds were degraded after 3 months. However, no tissue inflammation was observed. In conclusion, these promising results suggested that the incorporation of mg micro-particles into PCL porous scaffold could significantly enhance its mechanical and biological properties. This modified porous bio-scaffold may potentially apply in the surgical management of large bone defect fixation.

关键词： magnesium Polycaprolactone Biodegradability Biocompatibility mechanical properties

mass budgets of the Lambert, mellor and Fisher Glaciers and basal fluxes beneath their flowbands on Amery Ice Shelf

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Science China Earth Sciences 2007年第11期50卷 1693-1706页

作者： kenneth C. JEZEK Beata m. CSATHó Ute C. HERZFELd Katy L. FARNESS Philippe HUYBRECHTS Byrd Polar Research Center The Ohio State University Columbus OH 43210 USA CIRES/NSIdC University of Colorado Boulder Boulder CO 80309-0449 USA departement Geografie Vrije Universiteit Brussel Pleinlaan 2 B-1050 Brussels Belgium Alfred-Wegener-Institut für Polar-und Meeresforschung Postfach 120161 D-27515 Bremerhaven Germany

We used in situ measurements and remote-sensing data sets to evaluate the mass budgets of the Lambert, mellor and Fisher Glaciers and the basal melting and freezing rates beneath their flowbands on the Amery Ice Shelf. Our findings show the Lambert and mellor Glaciers upstream of the ANARE Lambert Glacier Basin (LGB) traverse may have positive imbalances of 3.9±2.1 Gt a-1 and 2.1±2.4 Gt a-1, respectively, while the Fisher Glacier is approximately in balance. The upstream region as a whole has a positive imbalance of 5.9±4.9 Gt a-1. The three same glaciers downstream of the ANARE LGB traverse line are in negative imbalance, where the whole downstream region has a negative imbalance of -8.5±5.8 Gt a-1. Overall the mass budgets of the Lambert, mellor, and Fisher Glaciers are close to bal-ance, and the collective three-glacier system is also nearly in balance with a mass budget of -2.6±6.5 Gt a-1. The significant positive imbalances for the interior basin upstream of the ice-movement stations established in the early 1970s (GL line) reported previously are possibly due to an overestimate of the total accumulation and an underestimate of the ice flux through the GL line. The mean melting rate is -23.0±3.5 m ice a-1 near the southern grounding line, which decreases rapidly downstream, and transitions to refreezing at around 300 km from the southern extremity of the Amery Ice Shelf. Freezing rates along the flowbands are around 0.5±0.1 to 1.5±0.2 m ice a-1. The per-centage of ice lost from the interior by basal melting beneath the flowbands is about 80%±5%. The total basal melting and refreezing beneath the three flowbands is 50.3±7.5 Gt ice a-1 and 7.0±1.1 Gt ice a-1, respectively. We find a much larger total basal melting and net melting than the results for the whole Amery Ice Shelf derived from previous modeling and oceanographic measurements.

关键词： mass budget basal melting and freezing Lambert Glacier Basin Amery Ice Shelf East Antarctica

A moringa Oleifera disinfectant-Sand Filter Integration： A Review of an Alternative Sustainable Technology for Household Water Treatment

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Journal of Environmental Science and Engineering 2011年第9期5卷 1100-1108页

作者： K.A. Yongabi d.m. Lewis P.L. harris department of Chemical Engineering The University of Adelaide Adelaide 5005 South Australia department of Agriculture and Wine Science The University of Adelaide Adelaide 5005 South Australia

This review provides an insight and up-to-date information on the application of moringa oleifera seeds, the short falls of existing technologies as a coagulant and disinfectant in domestic water treatment. While the coagulant properties are well reported, the disinfectant properties are not well studied. Literatures on low cost alternative technologies such as the application of hiocoagulants and slow sand filters are extensively reported. However, there is limited work addressing the limitations of these technologies that have restricted its widespread use to solve the global soaring water crises. Slow sand filters have a very slow filtration rate that depends on the biofilm layer which takes about 17 days to form. moringa oleifera treated water cannot last more than 48 hours without bacteria regrowth. Investigation of the best method of isolating coagulant component continues with differing opinions over the nature of its coagulant ingredient not resolved in ongoing literature. An attempt was made in this paper to highlight the advantages of a moringa disinfectant sand filter hybrid system that can purify water. microbiological advantages of this system in providing a 100% removal of pathogens, and engineering considerations such as water treatment within an hour residence time, faster flow rates, less clogging and backwashing could be some of the advantages ofa moringa sand filter system. The need to focus on integrating moringa and sand filter systems for more practical applications is recommended.

关键词： moringa oleifera disinfectant sand filter water integration review