An ontology-based search engine for protein-protein interactions

PubMed Central

2010-01-01

Background Keyword matching or ID matching is the most common searching method in a large database of protein-protein interactions. They are purely syntactic methods, and retrieve the records in the database that contain a keyword or ID specified in a query. Such syntactic search methods often retrieve too few search results or no results despite many potential matches present in the database. Results We have developed a new method for representing protein-protein interactions and the Gene Ontology (GO) using modified Gödel numbers. This representation is hidden from users but enables a search engine using the representation to efficiently search protein-protein interactions in a biologically meaningful way. Given a query protein with optional search conditions expressed in one or more GO terms, the search engine finds all the interaction partners of the query protein by unique prime factorization of the modified Gödel numbers representing the query protein and the search conditions. Conclusion Representing the biological relations of proteins and their GO annotations by modified Gödel numbers makes a search engine efficiently find all protein-protein interactions by prime factorization of the numbers. Keyword matching or ID matching search methods often miss the interactions involving a protein that has no explicit annotations matching the search condition, but our search engine retrieves such interactions as well if they satisfy the search condition with a more specific term in the ontology. PMID:20122195

An ontology-based search engine for protein-protein interactions.

PubMed

Park, Byungkyu; Han, Kyungsook

2010-01-18

Keyword matching or ID matching is the most common searching method in a large database of protein-protein interactions. They are purely syntactic methods, and retrieve the records in the database that contain a keyword or ID specified in a query. Such syntactic search methods often retrieve too few search results or no results despite many potential matches present in the database. We have developed a new method for representing protein-protein interactions and the Gene Ontology (GO) using modified Gödel numbers. This representation is hidden from users but enables a search engine using the representation to efficiently search protein-protein interactions in a biologically meaningful way. Given a query protein with optional search conditions expressed in one or more GO terms, the search engine finds all the interaction partners of the query protein by unique prime factorization of the modified Gödel numbers representing the query protein and the search conditions. Representing the biological relations of proteins and their GO annotations by modified Gödel numbers makes a search engine efficiently find all protein-protein interactions by prime factorization of the numbers. Keyword matching or ID matching search methods often miss the interactions involving a protein that has no explicit annotations matching the search condition, but our search engine retrieves such interactions as well if they satisfy the search condition with a more specific term in the ontology.

Impact of Neotectonic activities on coral reef Red Sea Egypt; Case study Jubal Island

NASA Astrophysics Data System (ADS)

Hamouda, A.

2016-12-01

Abstract:The Red Sea considered the youngest oceanic basin of the world. It separates the Arabian sub-plate from the African plate. Neotectonic activity is a fundamental issue at the northern Red Sea for our understanding of the tectonic hazards at this region. The tectonic activity research will thus be geared to understand how a single tectonic process works and how a group of processes work together as a part of larger system ultimately leading to the formation of mountain systems and evolution of the solid earth. The recent seismic activity in the northern Red Sea has been impact on surface geology and coral reef. The most major earthquake swarm sequence around Jubal Island is the migration of epicenters northward in diameter circle about 50 km with focal depths less than 2 to 15 km. This swarm may release energy that can be accumulated to cause larger events in the future. This affects the accumulation of oil and gas reservoir causing natural seepage on the seafloor. The main aim of this study represents the impact of this seepage which is related to tectonic activity on the coral reef states at the northern part of Red Sea. The greatest impact of crude oil on marine organisms are categorized as: direct lethal toxicity, sub-lethal disruption of physiological behavioral activities, effects of direct coating, incorporation of hydrocarbons and alteration of habitat, especially substrate character. Adult marine organisms may exhibit lethal toxic and Sub-lethal effects from exposures to soluble aromatic derivative hydrocarbons. Keywords: Neotectonic activity, earthquakes, hydrocarbon seepage, coral reef, Red Sea.

Google and Women’s Health-Related Issues: What Does the Search Engine Data Reveal?

PubMed Central

Baazeem, Mazin

2014-01-01

Objectives Identifying the gaps in public knowledge of women’s health related issues has always been difficult. With the increasing number of Internet users in the United States, we sought to use the Internet as a tool to help us identify such gaps and to estimate women’s most prevalent health concerns by examining commonly searched health-related keywords in Google search engine. Methods We collected a large pool of possible search keywords from two independent practicing obstetrician/gynecologists and classified them into five main categories (obstetrics, gynecology, infertility, urogynecology/menopause and oncology), and measured the monthly average search volume within the United States for each keyword with all its possible combinations using Google AdWords tool. Results We found that pregnancy related keywords were less frequently searched in general compared to other categories with an average of 145,400 hits per month for the top twenty keywords. Among the most common pregnancy-related keywords was “pregnancy and sex’ while pregnancy-related diseases were uncommonly searched. HPV alone was searched 305,400 times per month. Of the cancers affecting women, breast cancer was the most commonly searched with an average of 247,190 times per month, followed by cervical cancer then ovarian cancer. Conclusion The commonly searched keywords are often issues that are not discussed in our daily practice as well as in public health messages. The search volume is relatively related to disease prevalence with the exception of ovarian cancer which could signify a public fear. PMID:25422723

Presentations - Smith, J.R. and others, 2013 | Alaska Division of

Science.gov Websites

Engineering Geology Alaska Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to (1.4 M) Keywords Coastal; Coastal and River; Engineering Geology Posters and Presentations; Seward

Designing an Earthquake-Proof Art Museum: An Arts- and Engineering-Integrated Science Lesson

ERIC Educational Resources Information Center

Carignan, Anastasia; Hussain, Mahjabeen

2016-01-01

In this practical arts-integrated science and engineering lesson, an inquiry-based approach was adopted to teach a class of fourth graders in a Midwest elementary school about the scientific concepts of plate tectonics and earthquakes. Lessons were prepared following the 5 E instructional model. Next Generation Science Standards (4-ESS3-2) and the…

Interest in Anesthesia as Reflected by Keyword Searches using Common Search Engines

PubMed Central

Liu, Renyu; García, Paul S.; Fleisher, Lee A.

2012-01-01

Background Since current general interest in anesthesia is unknown, we analyzed internet keyword searches to gauge general interest in anesthesia in comparison with surgery and pain. Methods The trend of keyword searches from 2004 to 2010 related to anesthesia and anaesthesia was investigated using Google Insights for Search. The trend of number of peer reviewed articles on anesthesia cited on PubMed and Medline from 2004 to 2010 was investigated. The average cost on advertising on anesthesia, surgery and pain was estimated using Google AdWords. Searching results in other common search engines were also analyzed. Correlation between year and relative number of searches was determined with p< 0.05 considered statistically significant. Results Searches for the keyword “anesthesia” or “anaesthesia” diminished since 2004 reflected by Google Insights for Search (p< 0.05). The search for “anesthesia side effects” is trending up over the same time period while the search for “anesthesia and safety” is trending down. The search phrase “before anesthesia” is searched more frequently than “preanesthesia” and the search for “before anesthesia” is trending up. Using “pain” as a keyword is steadily increasing over the years indicated. While different search engines may provide different total number of searching results (available posts), the ratios of searching results between some common keywords related to perioperative care are comparable, indicating similar trend. The peer reviewed manuscripts on “anesthesia” and the proportion of papers on “anesthesia and outcome” are trending up. Estimates for spending of advertising dollars are less for anesthesia-related terms when compared to that for pain or surgery due to relative smaller number of searching traffic. Conclusions General interest in anesthesia (anaesthesia) as measured by internet searches appears to be decreasing. Pain, preanesthesia evaluation, anesthesia and outcome and side effects of anesthesia are the critical areas that anesthesiologists should focus on to address the increasing concerns. PMID:23853739

Interest in Anesthesia as Reflected by Keyword Searches using Common Search Engines.

PubMed

Liu, Renyu; García, Paul S; Fleisher, Lee A

2012-01-23

Since current general interest in anesthesia is unknown, we analyzed internet keyword searches to gauge general interest in anesthesia in comparison with surgery and pain. The trend of keyword searches from 2004 to 2010 related to anesthesia and anaesthesia was investigated using Google Insights for Search. The trend of number of peer reviewed articles on anesthesia cited on PubMed and Medline from 2004 to 2010 was investigated. The average cost on advertising on anesthesia, surgery and pain was estimated using Google AdWords. Searching results in other common search engines were also analyzed. Correlation between year and relative number of searches was determined with p< 0.05 considered statistically significant. Searches for the keyword "anesthesia" or "anaesthesia" diminished since 2004 reflected by Google Insights for Search (p< 0.05). The search for "anesthesia side effects" is trending up over the same time period while the search for "anesthesia and safety" is trending down. The search phrase "before anesthesia" is searched more frequently than "preanesthesia" and the search for "before anesthesia" is trending up. Using "pain" as a keyword is steadily increasing over the years indicated. While different search engines may provide different total number of searching results (available posts), the ratios of searching results between some common keywords related to perioperative care are comparable, indicating similar trend. The peer reviewed manuscripts on "anesthesia" and the proportion of papers on "anesthesia and outcome" are trending up. Estimates for spending of advertising dollars are less for anesthesia-related terms when compared to that for pain or surgery due to relative smaller number of searching traffic. General interest in anesthesia (anaesthesia) as measured by internet searches appears to be decreasing. Pain, preanesthesia evaluation, anesthesia and outcome and side effects of anesthesia are the critical areas that anesthesiologists should focus on to address the increasing concerns.

Earthquakes, Cities, and Lifelines: lessons integrating tectonics, society, and engineering in middle school Earth Science

NASA Astrophysics Data System (ADS)

Toke, N.; Johnson, A.; Nelson, K.

2010-12-01

Earthquakes are one of the most widely covered geologic processes by the media. As a result students, even at the middle school level, arrive in the classroom with preconceptions about the importance and hazards posed by earthquakes. Therefore earthquakes represent not only an attractive topic to engage students when introducing tectonics, but also a means to help students understand the relationships between geologic processes, society, and engineering solutions. Facilitating understanding of the fundamental connections between science and society is important for the preparation of future scientists and engineers as well as informed citizens. Here, we present a week-long lesson designed to be implemented in five one hour sessions with classes of ~30 students. It consists of two inquiry-based mapping investigations, motivational presentations, and short readings that describe fundamental models of plate tectonics, faults, and earthquakes. The readings also provide examples of engineering solutions such as the Alaskan oil pipeline which withstood multi-meter surface offset in the 2002 Denali Earthquake. The first inquiry-based investigation is a lesson on tectonic plates. Working in small groups, each group receives a different world map plotting both topography and one of the following data sets: GPS plate motion vectors, the locations and types of volcanoes, the location of types of earthquakes. Using these maps and an accompanying explanation of the data each group’s task is to map plate boundary locations. Each group then presents a ~10 minute summary of the type of data they used and their interpretation of the tectonic plates with a poster and their mapping results. Finally, the instructor will facilitate a class discussion about how the data types could be combined to understand more about plate boundaries. Using student interpretations of real data allows student misconceptions to become apparent. Throughout the exercise we record student preconceptions and post them to a bulletin board. During the tectonics unit we use these preconceptions as teaching tools. We also archive the misconceptions via a website which will be available for use by the broader geoscience education community. The second student investigation focuses on understanding the impact earthquakes have on nearby cities. We use the example of the 2009 southern San Andreas Fault (SAF) shakeout scenario. Students again break into groups. Each group is given an aspect of urban infrastructure to study relative to the underlying geology and location of nearby faults. Their goal is to uncover potential urban infrastructure issues related to a major earthquake on the SAF. For example students will map transportation ways crossing the fault, the location of hospitals relative to forecasted shaking hazards, the location of poverty-stricken areas relative to shaking hazards, and utilities relative to fault crossings. Again, students are tasked with explaining their investigation and analyses to the class with ample time for discussion about potential ways to solve problems identified through their investigations.

Development of a Taxonomy of Keywords for Engineering Education Research

ERIC Educational Resources Information Center

Finelli, Cynthia J.; Borrego, Maura; Rasoulifar, Golnoosh

2016-01-01

The diversity of engineering education research provides an opportunity for cross-fertilisation of ideas and creativity, but it also can result in fragmentation of the field and duplication of effort. One solution is to establish a standardised taxonomy of engineering education terms to map the field and communicate and connect research…

A Random Sample

ERIC Educational Resources Information Center

Cochran, Wendell

1976-01-01

Presented is a review of papers presented at the 25th International Geological Congress held August 16-25, 1976, Sydney, Australia. Topics include precambrian geology, tectonics, biostratigraphy, geochemistry, quaternary geology, engineering geology, planetology, geological education, and stress environments. (SL)

Googling NDIS: Evaluating the Quality of Online Information about the National Disability Insurance Scheme for Caregivers of Deaf Children

ERIC Educational Resources Information Center

Simpson, Andrea; Baldwin, Elizabeth Margaret

2017-01-01

This study sought to analyze and evaluate the accessibility, availability and quality of online information regarding the National Disability Insurance Scheme (NDIS) and hearing loss. The most common search engine keyword terms a caregiver may enter when conducting a web search was determined using a keyword search tool. The top websites linked…

Engineered Resilient Systems: A DoD Perspective

DTIC Science & Technology

2014-01-01

Selection and peer-review under responsibility of the University of Southern California. doi: 10.1016/j.procs.2014.03.103 ScienceDirect Conference...Selection and peer-review under responsibility of the University of Southern California. Keywords:rResilience, decision analysis, ERS, Engineered...Michael Sievers, Jet Propulsion Laboratory; Marilee Wheaton, The Aerospace Corporation Redondo Beach, CA, March 21-22, 2014 Engineered Resilient

Get Beyond Limits: From Colloidal Tectonics Concept to the Engineering of Eco-friendly Catalytic Systems

NASA Astrophysics Data System (ADS)

Leclercq, Loïc

2018-05-01

The interactions between two or more molecules or colloidal particles can be used to obtain a variety of self-assembled systems called supramolecules or supracolloids. There is a clear, but neglected, convergence between these two fields. Indeed, the packing of molecules into colloidal or supracolloidal particles emerges as a smart solution to build an infinite variety of reversible systems with predictable properties. In this respect, the molecular building blocks are called “tectons” whereas “colloidal tectonics” describes the spontaneous formation of (supra)colloidal structures using tectonic subunits. As a consequence, a bottom-up edification is allowed from tectons into (supra)colloidal particles with higher degrees of organization. These (supra)colloidal systems can be very useful to obtain catalysts with tunable amphiphilic properties. In this perspective, an overview of colloidal tectonics concept is presented as well as its use for the design of new, smart and flexible catalytic systems. Finally, the advantages of these catalytic devices are discussed and the perspective of future developments is addressed especially in the context of “green chemistry”.

Get Beyond Limits: From Colloidal Tectonics Concept to the Engineering of Eco-Friendly Catalytic Systems

PubMed Central

Leclercq, Loïc

2018-01-01

The interactions between two or more molecules or colloidal particles can be used to obtain a variety of self-assembled systems called supramolecules or supracolloids. There is a clear, but neglected, convergence between these two fields. Indeed, the packing of molecules into colloidal or supracolloidal particles emerges as a smart solution to build an infinite variety of reversible systems with predictable properties. In this respect, the molecular building blocks are called “tectons” whereas “colloidal tectonics” describes the spontaneous formation of (supra)colloidal structures using tectonic subunits. As a consequence, a bottom-up edification is allowed from tectons into (supra)colloidal particles with higher degrees of organization (Graphical Abstract). These (supra)colloidal systems can be very useful to obtain catalysts with tunable amphiphilic properties. In this perspective, an overview of colloidal tectonics concept is presented as well as its use for the design of new, smart, and flexible catalytic systems. Finally, the advantages of these catalytic devices are discussed and the perspective of future developments is addressed especially in the context of “green chemistry.”

EasyKSORD: A Platform of Keyword Search Over Relational Databases

NASA Astrophysics Data System (ADS)

Peng, Zhaohui; Li, Jing; Wang, Shan

Keyword Search Over Relational Databases (KSORD) enables casual users to use keyword queries (a set of keywords) to search relational databases just like searching the Web, without any knowledge of the database schema or any need of writing SQL queries. Based on our previous work, we design and implement a novel KSORD platform named EasyKSORD for users and system administrators to use and manage different KSORD systems in a novel and simple manner. EasyKSORD supports advanced queries, efficient data-graph-based search engines, multiform result presentations, and system logging and analysis. Through EasyKSORD, users can search relational databases easily and read search results conveniently, and system administrators can easily monitor and analyze the operations of KSORD and manage KSORD systems much better.

Searchers Net Treasure in Monterey.

ERIC Educational Resources Information Center

McDermott, Irene E.

1999-01-01

Reports on Web keyword searching, metadata, Dublin Core, Extensible Markup Language (XML), metasearch engines (metasearch engines search several Web indexes and/or directories and/or Usenet and/or specific Web sites), and the Year 2000 (Y2K) dilemma, all topics discussed at the second annual Internet Librarian Conference sponsored by Information…

A Management Information System for Bare Base Civil Engineering Commanders

DTIC Science & Technology

1988-09-01

initial beddown stage. The purpose of this research was to determine the feasibility of developing a microcomputer based management information system (MIS...the software best suited to synthesize four of the categories into a prototype field MIS. Keyword: Management information system , Bare bases, Civil engineering, Data bases, Information retrieval.

Index Relativity and Patron Search Strategy.

ERIC Educational Resources Information Center

Allison, DeeAnn; Childers Scott

2002-01-01

Describes a study at the University of Nebraska-Lincoln that compared searches in two different keyword indexes with similar content where search results were dependent on search strategy quality, search engine execution, and content. Results showed search engine execution had an impact on the number of matches and that users ignored search help…

Modeling Marrow Failure and MDS for Novel Therapeutics

DTIC Science & Technology

2017-03-01

predisposition syndrome Shwachman-Diamond syndrome (SDS) into which a deletion of the MDS-associated region of 7q has been genomically engineered . We...associated region of 7q has been genomically engineered . We will perform functional genomic screens to identify genes and molecular pathways with...disease arising from marrow failure. 2. Keywords Bone marrow failure, clonal evolution, induced pluripotent stem cells, genomic engineering 3

Plain Language to Communicate Physical Activity Information: A Website Content Analysis.

PubMed

Paige, Samantha R; Black, David R; Mattson, Marifran; Coster, Daniel C; Stellefson, Michael

2018-04-01

Plain language techniques are health literacy universal precautions intended to enhance health care system navigation and health outcomes. Physical activity (PA) is a popular topic on the Internet, yet it is unknown if information is communicated in plain language. This study examined how plain language techniques are included in PA websites, and if the use of plain language techniques varies according to search procedures (keyword, search engine) and website host source (government, commercial, educational/organizational). Three keywords ("physical activity," "fitness," and "exercise") were independently entered into three search engines (Google, Bing, and Yahoo) to locate a nonprobability sample of websites ( N = 61). Fourteen plain language techniques were coded within each website to examine content formatting, clarity and conciseness, and multimedia use. Approximately half ( M = 6.59; SD = 1.68) of the plain language techniques were included in each website. Keyword physical activity resulted in websites with fewer clear and concise plain language techniques ( p < .05), whereas fitness resulted in websites with more clear and concise techniques ( p < .01). Plain language techniques did not vary by search engine or the website host source. Accessing PA information that is easy to understand and behaviorally oriented may remain a challenge for users. Transdisciplinary collaborations are needed to optimize plain language techniques while communicating online PA information.

Effects of Pulsing on Film Cooling of Gas Turbine Airfoils

DTIC Science & Technology

2005-05-09

turbine engine . 15. NUMBER OF PAGES 70 14. SUBJECT TERMS: Turbine blade ; Film cooling ; Pulsed jet 16. PRICE CODE 17...with additional research, ultimately allowing for an increased efficiency in a gas turbine engine . 2 Keywords Turbine blade Film cooling Pulsed jet ... engine for aircraft propulsion…………………. 11 Figure 2: Thermodynamic cycle of a general turbine engine . ………………………..…… 11

The present geodynamics of Albania

NASA Astrophysics Data System (ADS)

Koçi, Rexhep; Dushi, Edmond; Begu, Enkela; Bozo, Rrezart

2017-04-01

Geological structure of Albania comprises different formations widely varying in age beginning since the Paleozoic era to Quaternary. From the tectonic stand point Albanides belongs to folded Alpine belt, representing a particular node in the geology of the Mediterranean Alps. Albanian geological environment have a long and complicated history. It is folded and dissected by many tectonic faults. During the Alpine geological evolution of Albanides, an imbricated tectonic thrusting system, with considerable amplitude, has been developed in the outer part, while a series of normal faults have been developed in the inner part. The convergence of the geological structures is southwest oriented, from inner to external tectonic area, associated by mass displacement. These displacements can be observed nowadays from geodynamic measurements, of the GPS networks in Albania, and the surrounding. GPS data for Albanian territory, recorded during a 10-years period, in reference to the Eurasia and Apulia plates, reveal an important pre-Pliocene compression of the outer Albanides, including Sazani, Ionian and Kruja zones, undergoing a major post-Pliocene shortening in the western side. The outer Albanides are structured by infringements of over-thrust and up-thrust type, by NNW-SSE oriented folds, which in some cases are dislocated by transverse faults, of NE orientation. Actual results from GPS measurements of the points located in outer Albanides show a displacement towards west and northwest in relation to Eurasia, and southwest in relation to Apulia block. From numerous focal mechanisms solutions (FMS) of shallow earthquakes it results a horizontal compression dominating along the Adriatic collision contact. Active tectonics in this area is reflected from historical and instrumental strong earthquakes. Quite often, they are generated from the activation of tectonic faults, which in turn are responsible for this seismic activity of the country. Referring to the historical data, the whole territory of Balkans and its southwest territory in particular, is characterized by a high seismicity rate. In general, Albanian seismicity is characterized by an intense micro-activity (1.0 ≤ M ≤ 3.0), by many small earthquakes (3.0 ≤ M ≤ 5.0), by medium size earthquakes (5.0 ≤ M ≤ 7.0) and very seldom by strong ones (M > 7.0). This paper aims a general representation of the geodynamics of Albania, based on recent results from earthquake and GPS instrumental data. Keywords: Albanides, frontal collision, thrusting system, normal faults

10 CFR 100.23 - Geologic and seismic siting criteria.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Earthquake Ground Motion, and to permit adequate engineering solutions to actual or potential geologic and..., earthquake recurrence rates, fault geometry and slip rates, site foundation material, and seismically induced... Earthquake Ground Motion for the site, the potential for surface tectonic and nontectonic deformations, the...

10 CFR 100.23 - Geologic and seismic siting criteria.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Earthquake Ground Motion, and to permit adequate engineering solutions to actual or potential geologic and..., earthquake recurrence rates, fault geometry and slip rates, site foundation material, and seismically induced... Earthquake Ground Motion for the site, the potential for surface tectonic and nontectonic deformations, the...

10 CFR 100.23 - Geologic and seismic siting criteria.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Earthquake Ground Motion, and to permit adequate engineering solutions to actual or potential geologic and..., earthquake recurrence rates, fault geometry and slip rates, site foundation material, and seismically induced... Earthquake Ground Motion for the site, the potential for surface tectonic and nontectonic deformations, the...

Fuzzy Logic Modelling and Hidden Geodynamic Parameters of Earth: What is the role of Fluid Pathaways and Hydrothermal Stages on the Mineralization Variations of Kozbudaklar Pluton over Southern Uludag

NASA Astrophysics Data System (ADS)

Kocaturk, Huseyin; Kumral, Mustafa

2016-04-01

Plate tectonics is one of the most illustrated theory and biggest geo-dynamic incident on earth surface and sub-surface for the earth science. Tectonic settlement, rock forming minerals, form of stratigraphy, ore genesis processes, crystal structures and even rock textures are all related with plate tectonic. One of the most known region of Turkey is Southern part of Uludaǧ and has been defined with three main lithological union. Region is formed with metamorphics, ophiolites and magmatic intrusions which are generally I-type granodiorites. Also these intrusion related rocks has formed and altered by high grade hydrothermal activity. This study approaches to understand bigger to smaller frameworks of these processes which between plate tectonics and fluid pathways. Geodynamic related fuzzy logic modelling is present us compact conclusion report about structural associations for the economic generations. Deformation structures and fluid pathways which related with plate tectonics progressed on our forearc system and each steps of dynamic movements of subducting mechanism has been seemed affect both hydrothermal stages and mineral variations together. Types of each deformation structure and mineral assemblages has characterized for flux estimations which can be useful for subsurface mapping. Geoanalytical results showed us clear characteristic stories for mutual processes. Determined compression and release directions on our map explains not only hydrothermal stages but also how succesion of intrusions changes. Our fuzzy logic models intersect sections of physical and chemical interactions of study field. Researched parameters like mafic minerals and enclave ratios on different deformation structures, cross sections of structures and relative existing sequence are all changes with different time periods like geochemical environment and each vein. With the combined informations in one scene we can transact mineralization processes about region which occurs in different stages such as subducting slabs, arc volcanism, subsurface flux estimates related orogenic processes, and other geochemical effects of plate movements. Keywords: Hydrothermal Stages, Flux Estimate, Southern Region of Uludaǧ, Subsurface Mapping

Applying Early Systems Engineering: Injecting Knowledge into the Capability Development Process

DTIC Science & Technology

2012-10-01

involves early use of systems engi- neering and technical analyses to supplement the existing operational analysis techniques currently used in...complexity, and costs of systems now being developed require tight coupling between operational requirements stated in the CDD, system requirements...Fleischer » Keywords: Capability Development, Competitive Prototyping, Knowledge Points, Early Systems Engineering Applying Early Systems

Understanding the Miocene-Pliocene - The Mediterranean Point of View

NASA Astrophysics Data System (ADS)

Simon, D.; Marzocchi, A.; Lunt, D. J.; Flecker, R.; Hilgen, F. J.; Meijer, P. T.

2015-12-01

During the Miocene-Pliocene the Mediterranean region experienced major changes in paleogeography. Today, its only connection to the global ocean is the Strait of Gibraltar. This restricted nature causes the Mediterranean basin to react more sensitive to climatic and tectonic related phenomena than the global ocean: Not just eustatic sea-level and regional river run-off, but also gateway tectonics and connectivity between sub-basins are leaving an enhanced fingerprint in its geological record. To understand its evolution, it is crucial to understand how these different effects are coupled. The Miocene-Pliocene sedimentary record of the Mediterranean alternates in composition and colour. Around the Miocene-Pliocene Boundary the most extreme changes occur in the Mediterranean Sea: About 6% of the salt in the global ocean got deposited in the Mediterranean Region, forming an approximately 2km thick salt layer, which is still present today. This extreme event is named the Messinian Salinity Crisis (MSC, 5.97-5.33Ma). Before (and also after) the MSC, the sedimentary record demonstrates "marl dominated" alternations with variations in organic content (e.g. higher organic content = sapropel). During the MSC these change to mainly "evaporite (e.g. gypsum or halite) dominated" alternations, but also to brackish Black Sea-type of deposits towards the end of the crisis. Due to its relative short geological time span, the period before, during and after the MSC is ideal to study these extreme changes in sedimentation. We are investigating these couplings and evolutions in a box/budget model. With such a model we can study the responses to basin water exchange dynamics under the effect of different regional and global climatic and tectonic forcings, to predict the evolution of basin properties (e.g. salinity). By doing so we can isolate certain climatic and tectonic effects, to better understand their individual contribution, their interaction, but also the consequences due to their coupling. Keywords: Mediterranean Sea, Climate, Coupling, Evolution, Messinian Salinity Crisis, Modeling, Strait of Gibraltar, GCM

The Australian Computational Earth Systems Simulator

NASA Astrophysics Data System (ADS)

Mora, P.; Muhlhaus, H.; Lister, G.; Dyskin, A.; Place, D.; Appelbe, B.; Nimmervoll, N.; Abramson, D.

2001-12-01

Numerical simulation of the physics and dynamics of the entire earth system offers an outstanding opportunity for advancing earth system science and technology but represents a major challenge due to the range of scales and physical processes involved, as well as the magnitude of the software engineering effort required. However, new simulation and computer technologies are bringing this objective within reach. Under a special competitive national funding scheme to establish new Major National Research Facilities (MNRF), the Australian government together with a consortium of Universities and research institutions have funded construction of the Australian Computational Earth Systems Simulator (ACcESS). The Simulator or computational virtual earth will provide the research infrastructure to the Australian earth systems science community required for simulations of dynamical earth processes at scales ranging from microscopic to global. It will consist of thematic supercomputer infrastructure and an earth systems simulation software system. The Simulator models and software will be constructed over a five year period by a multi-disciplinary team of computational scientists, mathematicians, earth scientists, civil engineers and software engineers. The construction team will integrate numerical simulation models (3D discrete elements/lattice solid model, particle-in-cell large deformation finite-element method, stress reconstruction models, multi-scale continuum models etc) with geophysical, geological and tectonic models, through advanced software engineering and visualization technologies. When fully constructed, the Simulator aims to provide the software and hardware infrastructure needed to model solid earth phenomena including global scale dynamics and mineralisation processes, crustal scale processes including plate tectonics, mountain building, interacting fault system dynamics, and micro-scale processes that control the geological, physical and dynamic behaviour of earth systems. ACcESS represents a part of Australia's contribution to the APEC Cooperation for Earthquake Simulation (ACES) international initiative. Together with other national earth systems science initiatives including the Japanese Earth Simulator and US General Earthquake Model projects, ACcESS aims to provide a driver for scientific advancement and technological breakthroughs including: quantum leaps in understanding of earth evolution at global, crustal, regional and microscopic scales; new knowledge of the physics of crustal fault systems required to underpin the grand challenge of earthquake prediction; new understanding and predictive capabilities of geological processes such as tectonics and mineralisation.

The Early Detection of Pancreatic Cancer in the U. S. Military

DTIC Science & Technology

2015-10-01

exhaust and cigarette smoke contribute to the higher rates of pancreatic cancer in military personnel. This heightened risk is due in part to the...elevated exposure to carcinogens present in diesel engine exhaust and cigarette smoke, such as polycyclic aromatic hydrocarbons (PAHs) and heavy metals...KEYWORDS: Pancreatic ductal adenocarcinoma, early detection, carcinogenesis, military, diesel engine exhaust, cigarette smoke, organoids. ACCOMPLISHMENTS

Information Retrieval for Education: Making Search Engines Language Aware

ERIC Educational Resources Information Center

Ott, Niels; Meurers, Detmar

2010-01-01

Search engines have been a major factor in making the web the successful and widely used information source it is today. Generally speaking, they make it possible to retrieve web pages on a topic specified by the keywords entered by the user. Yet web searching currently does not take into account which of the search results are comprehensible for…

Summary of Research 1998, Department of Mechanical Engineering.

DTIC Science & Technology

1999-08-01

thermoacoustic behavior in strong zero-mean oscillatory flows with potential application to the design of heat exchangers in thermoacoustic engines...important feature in the thermal characterization of microtubes , which are to be used in microheat exchangers . DoD KEY TECHNOLOGY AREA: Modeling and...Simulation KEYWORDS: Laminar Duct Flows, Convection and Conduction Heat Transfer, Axial Conduction, Micro- heat Exchang - ers DEVELOPMENT AND CALIBRATION

The Early Detection of Pancreatic Cancer in the U.S. Military

DTIC Science & Technology

2015-10-01

exhaust and cigarette smoke contribute to the higher rates of pancreatic cancer in military personnel. This heightened risk is due in part to the...elevated exposure to carcinogens present in diesel engine exhaust and cigarette smoke, such as polycyclic aromatic hydrocarbons (PAHs) and heavy metals...KEYWORDS: Pancreatic ductal adenocarcinoma, early detection, carcinogenesis, military, diesel engine exhaust, cigarette smoke, organoids. ACCOMPLISHMENTS

Earth tides, global heat flow, and tectonics

USGS Publications Warehouse

Shaw, H.R.

1970-01-01

The power of a heat engine ignited by tidal energy can account for geologically reasonable rates of average magma production and sea floor spreading. These rates control similarity of heat flux over continents and oceans because of an inverse relationship between respective depth intervals for mass transfer and consequent distributions of radiogenic heat production.

Minimum and Maximum Entropy Distributions for Binary Systems with Known Means and Pairwise Correlations

DTIC Science & Technology

2017-08-21

distributions, and we discuss some applications for engineered and biological information transmission systems. Keywords: information theory; minimum...of its interpretation as a measure of the amount of information communicable by a neural system to groups of downstream neurons. Previous authors...of the maximum entropy approach. Our results also have relevance for engineered information transmission systems. We show that empirically measured

Health literacy and usability of clinical trial search engines.

PubMed

Utami, Dina; Bickmore, Timothy W; Barry, Barbara; Paasche-Orlow, Michael K

2014-01-01

Several web-based search engines have been developed to assist individuals to find clinical trials for which they may be interested in volunteering. However, these search engines may be difficult for individuals with low health and computer literacy to navigate. The authors present findings from a usability evaluation of clinical trial search tools with 41 participants across the health and computer literacy spectrum. The study consisted of 3 parts: (a) a usability study of an existing web-based clinical trial search tool; (b) a usability study of a keyword-based clinical trial search tool; and (c) an exploratory study investigating users' information needs when deciding among 2 or more candidate clinical trials. From the first 2 studies, the authors found that users with low health literacy have difficulty forming queries using keywords and have significantly more difficulty using a standard web-based clinical trial search tool compared with users with adequate health literacy. From the third study, the authors identified the search factors most important to individuals searching for clinical trials and how these varied by health literacy level.

Automated Data Tagging in the HLA

NASA Astrophysics Data System (ADS)

Gaffney, N. I.; Miller, W. W.

2008-08-01

One of the more powerful and popular forms of data organization implemented in most popular information sharing web applications is data tagging. With a rich user base from which to gather and digest tags, many interesting and often unanticipated yet very useful associations are revealed. With regard to an existing information, the astronomical community has a rich pool of existing digitally stored and searchable data than any of the currently popular web community, such as You Tube or My Space, had when they started. In initial experiments with the search engine for the Hubble Legacy Archive, we have created a simple yet powerful scheme by which the information from a footprint service, the NED and SIMBAD catalog services, and the ADS abstracts and keywords can be used to initially tag data with standard keywords. By then ingesting this into a public ally available information search engine, such as Apache Lucene, one can create a simple and powerful data tag search engine and association system. By then augmenting this with user provided keys and usage pattern analysis, one can produce a powerful modern data mining system for any astronomical data warehouse.

Creating global comparative analyses of tectonic rifts, monogenetic volcanism and inverted relief

NASA Astrophysics Data System (ADS)

van Wyk de Vries, Benjamin

2016-04-01

I have been all around the world, and to other planets and have travelled from the present to the Archaean and back to seek out the most significant tectonic rifts, monogenetic volcanoes and examples of inverted relief. I have done this to provide a broad foundation of the comparative analysis for the Chaîne des Puys - Limagne fault nomination to UNESCO world Heritage. This would have been an impossible task, if not for the cooperation of the scientific community and for Google Earth, Google Maps and academic search engines. In preparing global comparisons of geological features, these quite recently developed tools provide a powerful way to find and describe geological features. The ability to do scientific crowd sourcing, rapidly discussing with colleagues about features, allows large numbers of areas to be checked and the open GIS tools (such as Google Earth) allow a standardised description. Search engines also allow the literature on areas to be checked and compared. I will present a comparative study of rifts of the world, monogenetic volcanic field and inverted relief, integrated to analyse the full geological system represented by the Chaîne des Puys - Limagne fault. The analysis confirms that the site is an exceptional example of the first steps of continental drift in a mountain rift setting, and that this is necessarily seen through the combined landscape of tectonic, volcanic and geomorphic features. The analysis goes further to deepen the understanding of geological systems and stresses the need for more study on geological heritage using such a global and broad systems approach.

Science on Stage: Engaging and teaching scientific content through performance art

NASA Astrophysics Data System (ADS)

Posner, Esther

2016-04-01

Engaging teaching material through performance art and music can improve the long-term retention of scientific content. Additionally, the development of effective performance skills are a powerful tool to communicate scientific concepts and information to a broader audience that can have many positive benefits in terms of career development and the delivery of professional presentations. While arts integration has been shown to increase student engagement and achievement, relevant artistic materials are still required for use as supplemental activities in STEM (science, technology, engineering, mathematics) courses. I will present an original performance poem, "Tectonic Petrameter: A Journey Through Earth History," with instructions for its implementation as a play in pre-university and undergraduate geoscience classrooms. "Tectonic Petrameter" uses a dynamic combination of rhythm and rhyme to teach the geological time scale, fundamental concepts in geology and important events in Earth history. I propose that using performance arts, such as "Tectonic Petrameter" and other creative art forms, may be an avenue for breaking down barriers related to teaching students and the broader non-scientific community about Earth's long and complex history.

Publications - RDF 2016-6 v. 1.1 | Alaska Division of Geological &

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska 345.0 K Metadata - Read me Keywords Alaska Range; Analyses; Analyses and Sampling; Analytical Lab

Intelligent web image retrieval system

NASA Astrophysics Data System (ADS)

Hong, Sungyong; Lee, Chungwoo; Nah, Yunmook

2001-07-01

Recently, the web sites such as e-business sites and shopping mall sites deal with lots of image information. To find a specific image from these image sources, we usually use web search engines or image database engines which rely on keyword only retrievals or color based retrievals with limited search capabilities. This paper presents an intelligent web image retrieval system. We propose the system architecture, the texture and color based image classification and indexing techniques, and representation schemes of user usage patterns. The query can be given by providing keywords, by selecting one or more sample texture patterns, by assigning color values within positional color blocks, or by combining some or all of these factors. The system keeps track of user's preferences by generating user query logs and automatically add more search information to subsequent user queries. To show the usefulness of the proposed system, some experimental results showing recall and precision are also explained.

Finding and Exploring Health Information with a Slider-Based User Interface.

PubMed

Pang, Patrick Cheong-Iao; Verspoor, Karin; Pearce, Jon; Chang, Shanton

2016-01-01

Despite the fact that search engines are the primary channel to access online health information, there are better ways to find and explore health information on the web. Search engines are prone to problems when they are used to find health information. For instance, users have difficulties in expressing health scenarios with appropriate search keywords, search results are not optimised for medical queries, and the search process does not account for users' literacy levels and reading preferences. In this paper, we describe our approach to addressing these problems by introducing a novel design using a slider-based user interface for discovering health information without the need for precise search keywords. The user evaluation suggests that the interface is easy to use and able to assist users in the process of discovering new information. This study demonstrates the potential value of adopting slider controls in the user interface of health websites for navigation and information discovery.

In Search of Search Engine Marketing Strategy Amongst SME's in Ireland

NASA Astrophysics Data System (ADS)

Barry, Chris; Charleton, Debbie

Researchers have identified the Web as a searchers first port of call for locating information. Search Engine Marketing (SEM) strategies have been noted as a key consideration when developing, maintaining and managing Websites. A study presented here of SEM practices of Irish small to medium enterprises (SMEs) reveals they plan to spend more resources on SEM in the future. Most firms utilize an informal SEM strategy, where Website optimization is perceived most effective in attracting traffic. Respondents cite the use of ‘keywords in title and description tags’ as the most used SEM technique, followed by the use of ‘keywords throughout the whole Website’; while ‘Pay for Placement’ was most widely used Paid Search technique. In concurrence with the literature, measuring SEM performance remains a significant challenge with many firms unsure if they measure it effectively. An encouraging finding is that Irish SMEs adopt a positive ethical posture when undertaking SEM.

[Pruritus in Germany-a Google search engine analysis].

PubMed

Zink, A; Rüth, M; Schuster, B; Darsow, U; Biedermann, T; Ständer, S

2018-06-06

Because affected persons often do not visit a doctor, the prevalence of chronic and acute pruritus in the general population is difficult to determine. The aim of this study is to estimate the frequency and the most common locations of pruritus in German internet users, who-with 62.4 million persons-represent a large majority of the German population, by analysing the Google search volume. Relevant keywords for the subject "pruritus" were identified and analysed using the Google AdWords Keyword Planner. The assessment period was January 2015 to December 2016. In total the Google AdWords Keyword Planner identified 701 keywords for the topic "Juckreiz" (German lay word for pruritus), resulting in 7,531,890 pruritus-related Google searches during the assessment period. Most common search terms were the German lay term for atopic eczema ("Neurodermitis", 23.7%), the German lay term for psoriasis ("Schuppenflechte", 17.8%) and "psoriasis" (13%). The German lay term for pruritus ("Juckreiz") was only the sixth most searched term (3%). Most searches (72%) focused on influencing factors for pruritus, especially on skin diseases and skin conditions. The most commonly searched location was pruritus on the whole body, followed by anal pruritus. Analysis of the temporal course showed a higher monthly search volume during winter. With its unconventional methodology, a Google search engine analysis, this study allows a rough estimation of the medical need of pruritus in the German general population, which seems to be higher than expected. Especially pruritus in the anal area was identified as an unmet medical need.

The Exponential Expansion of Simulation in Research

DTIC Science & Technology

2012-12-01

exponential growth of computing power. Although other analytic approaches also benefit from this trend, keyword searches of several scholarly search ... engines reveal that the reliance on simulation is increasing more rapidly. A descriptive analysis paints a compelling picture: simulation is frequently

What Can Pictures Tell Us About Web Pages? Improving Document Search Using Images.

PubMed

Rodriguez-Vaamonde, Sergio; Torresani, Lorenzo; Fitzgibbon, Andrew W

2015-06-01

Traditional Web search engines do not use the images in the HTML pages to find relevant documents for a given query. Instead, they typically operate by computing a measure of agreement between the keywords provided by the user and only the text portion of each page. In this paper we study whether the content of the pictures appearing in a Web page can be used to enrich the semantic description of an HTML document and consequently boost the performance of a keyword-based search engine. We present a Web-scalable system that exploits a pure text-based search engine to find an initial set of candidate documents for a given query. Then, the candidate set is reranked using visual information extracted from the images contained in the pages. The resulting system retains the computational efficiency of traditional text-based search engines with only a small additional storage cost needed to encode the visual information. We test our approach on one of the TREC Million Query Track benchmarks where we show that the exploitation of visual content yields improvement in accuracies for two distinct text-based search engines, including the system with the best reported performance on this benchmark. We further validate our approach by collecting document relevance judgements on our search results using Amazon Mechanical Turk. The results of this experiment confirm the improvement in accuracy produced by our image-based reranker over a pure text-based system.

Seeking health information online: does Wikipedia matter?

PubMed

Laurent, Michaël R; Vickers, Tim J

2009-01-01

OBJECTIVE To determine the significance of the English Wikipedia as a source of online health information. DESIGN The authors measured Wikipedia's ranking on general Internet search engines by entering keywords from MedlinePlus, NHS Direct Online, and the National Organization of Rare Diseases as queries into search engine optimization software. We assessed whether article quality influenced this ranking. The authors tested whether traffic to Wikipedia coincided with epidemiological trends and news of emerging health concerns, and how it compares to MedlinePlus. MEASUREMENTS Cumulative incidence and average position of Wikipedia compared to other Web sites among the first 20 results on general Internet search engines (Google, Google UK, Yahoo, and MSN, and page view statistics for selected Wikipedia articles and MedlinePlus pages. RESULTS Wikipedia ranked among the first ten results in 71-85% of search engines and keywords tested. Wikipedia surpassed MedlinePlus and NHS Direct Online (except for queries from the latter on Google UK), and ranked higher with quality articles. Wikipedia ranked highest for rare diseases, although its incidence in several categories decreased. Page views increased parallel to the occurrence of 20 seasonal disorders and news of three emerging health concerns. Wikipedia articles were viewed more often than MedlinePlus Topic (p = 0.001) but for MedlinePlus Encyclopedia pages, the trend was not significant (p = 0.07-0.10). CONCLUSIONS Based on its search engine ranking and page view statistics, the English Wikipedia is a prominent source of online health information compared to the other online health information providers studied.

When probabilistic seismic hazard climbs volcanoes: the Mt. Etna case, Italy - Part 2: Computational implementation and first results

NASA Astrophysics Data System (ADS)

Peruzza, Laura; Azzaro, Raffaele; Gee, Robin; D'Amico, Salvatore; Langer, Horst; Lombardo, Giuseppe; Pace, Bruno; Pagani, Marco; Panzera, Francesco; Ordaz, Mario; Suarez, Miguel Leonardo; Tusa, Giuseppina

2017-11-01

This paper describes the model implementation and presents results of a probabilistic seismic hazard assessment (PSHA) for the Mt. Etna volcanic region in Sicily, Italy, considering local volcano-tectonic earthquakes. Working in a volcanic region presents new challenges not typically faced in standard PSHA, which are broadly due to the nature of the local volcano-tectonic earthquakes, the cone shape of the volcano and the attenuation properties of seismic waves in the volcanic region. These have been accounted for through the development of a seismic source model that integrates data from different disciplines (historical and instrumental earthquake datasets, tectonic data, etc.; presented in Part 1, by Azzaro et al., 2017) and through the development and software implementation of original tools for the computation, such as a new ground-motion prediction equation and magnitude-scaling relationship specifically derived for this volcanic area, and the capability to account for the surficial topography in the hazard calculation, which influences source-to-site distances. Hazard calculations have been carried out after updating the most recent releases of two widely used PSHA software packages (CRISIS, as in Ordaz et al., 2013; the OpenQuake engine, as in Pagani et al., 2014). Results are computed for short- to mid-term exposure times (10 % probability of exceedance in 5 and 30 years, Poisson and time dependent) and spectral amplitudes of engineering interest. A preliminary exploration of the impact of site-specific response is also presented for the densely inhabited Etna's eastern flank, and the change in expected ground motion is finally commented on. These results do not account for M > 6 regional seismogenic sources which control the hazard at long return periods. However, by focusing on the impact of M < 6 local volcano-tectonic earthquakes, which dominate the hazard at the short- to mid-term exposure times considered in this study, we present a different viewpoint that, in our opinion, is relevant for retrofitting the existing buildings and for driving impending interventions of risk reduction.

Research on keyword retrieval method of HBase database based on index structure

NASA Astrophysics Data System (ADS)

Gong, Pijin; Lv, Congmin; Gong, Yongsheng; Ma, Haozhi; Sun, Yang; Wang, Lu

2017-10-01

With the rapid development of manned spaceflight engineering, the scientific experimental data in space application system is increasing rapidly. How to efficiently query the specific data in the mass data volume has become a problem. In this paper, a method of retrieving the object data based on the object attribute as the keyword is proposed. The HBase database is used to store the object data and object attributes, and the secondary index is constructed. The research shows that this method is a good way to retrieve specified data based on object attributes.

Probing Earth's State of Stress

NASA Astrophysics Data System (ADS)

Delorey, A. A.; Maceira, M.; Johnson, P. A.; Coblentz, D. D.

2016-12-01

The state of stress in the Earth's crust is a fundamental physical property that controls both engineered and natural systems. Engineered environments including those for hydrocarbon, geothermal energy, and mineral extraction, as well those for storage of wastewater, carbon dioxide, and nuclear fuel are as important as ever to our economy and environment. Yet, it is at spatial scales relevant to these activities where stress is least understood. Additionally, in engineered environments the rate of change in the stress field can be much higher than that of natural systems. In order to use subsurface resources more safely and effectively, we need to understand stress at the relevant temporal and spatial scales. We will present our latest results characterizing the state of stress in the Earth at scales relevant to engineered environments. Two important components of the state of stress are the orientation and magnitude of the stress tensor, and a measure of how close faults are to failure. The stress tensor at any point in a reservoir or repository has contributions from both far-field tectonic stress and local density heterogeneity. We jointly invert seismic (body and surface waves) and gravity data for a self-consistent model of elastic moduli and density and use the model to calculate the contribution of local heterogeneity to the total stress field. We then combine local and plate-scale contributions, using local indicators for calibration and ground-truth. In addition, we will present results from an analysis of the quantity and pattern of microseismicity as an indicator of critically stressed faults. Faults are triggered by transient stresses only when critically stressed (near failure). We show that tidal stresses can trigger earthquakes in both tectonic and reservoir environments and can reveal both stress and poroelastic conditions.

An Investigation on the Crustal Deformations in Istanbul after Eastern Marmara Earthquakes in 1999

NASA Astrophysics Data System (ADS)

Ozludemir, M.; Ozyasar, M.

2008-12-01

Since the introduction of the GPS technique in mid 1970's there has been great advances in positioning activities. Today such Global Navigational Satellite Systems (GNSS) based positioning techniques are widely used in daily geodetic applications. High order geodetic network measurements are one of such geodetic applications. Such networks are established to provide reliable infrastructures for all kind of geodetic work from the production of cadastral plans to the surveying processes during the construction of engineering structures. In fact such positional information obtained in such engineering surveys could be useful for other studies as well. One of such fields is geodynamic studies where such positional information could be valuable to understand the characteristics of tectonic movements. In Turkey being located in a tectonically active zones and having major earthquakes quite frequently, the positional information obtained in engineering surveys could be very useful for earthquake related studies. In this paper an example of such engineering surveys is discussed. This example is the Istanbul GPS (Global Positioning System) Network, first established in 1997 and remeasured in 2005. Between these two measurement processes two major earthquakes took place, on August 17 and November 12, 1999 with magnitudes of 7.4 and 7.2, respectively. In the first measurement campaign in 1997, a network of about 700 points was measured, while in the second campaign in 2005 more than 1800 points were positioned. In these two campaigns are existing common points. The network covers the whole Istanbul area of about 6000 km2. All network points are located on the Eurasian plate to the north of the North Anatolian Fault Zone. In this study, the horizontal and vertical movements are presented and compared with the results obtained in geodynamic studies.

JournalMap: Research. Reimagined.

USDA-ARS?s Scientific Manuscript database

JournalMap is a scientific literature search engine that empowers you to find relevant research based on location and biophysical variables as well as traditional keyword searches. All publications are geotagged based on reported location information and plotted on a world map showing where the rese...

An Undergraduate Research Experience that Integrates Traditional Field Mapping, LiDAR, and 3D Numerical Modeling: Applying Lessons from a Recent Report from the National Academies of Sciences, Engineering, and Medicine in an Intermediate-Level Tectonic Landscapes Course

NASA Astrophysics Data System (ADS)

Reinen, L. A.; Brenner, K.

2017-12-01

Ongoing efforts to improve undergraduate education in science, technology, engineering, and mathematics (STEM) fields focus on increasing active student participation and decreasing traditional lecture-based teaching. Undergraduate research experiences (UREs), which engage students in the work of STEM professionals, are an example of these efforts. A recent report from the National Academies of Sciences, Engineering and Medicine (Undergraduate Research Experiences for STEM Students: Successes, Challenges, and Opportunities; 2017) provides characteristics of UREs, and indicates that participation in UREs increases student interest and persistence in STEM as well as provides opportunities to broaden student participation in these fields. UREs offer an excellent opportunity to engage students in research using the rapidly evolving technologies used by STEM professionals. In the fall of 2016, students in the Tectonic Landscapes class at Pomona College participated in a course-based URE that combined traditional field mapping methods with analysis of high-resolution topographic data (LiDAR) and 3D numerical modeling to investigate questions of active local faulting. During the first ten weeks students developed skills in: creation of fault maps from both field observations (GPS included) and high-resolution digital elevation models (DEMs), assessment of tectonic activity through analyses of DEMs of hill slope diffusion models and geomorphic indices, and evaluation of fault geometry hypotheses via 3D elastic modeling. Most of these assignments were focused on a single research site. While students primarily used Excel, ArcMap, and Poly3D, no previous knowledge of these was required or assumed. Through this iterative approach, students used increasingly more complex methods as well as gained greater ownership of the research process with time. The course culminated with a 4-week independent research project in which each student investigated a question of their own choosing using skills developed earlier in the course. We will provide details of the course, scaffolding of the technical skills, growing the independence of students in the research process, and discuss early outcomes of student confidence, engagement and retention.

Development and evaluation of a biomedical search engine using a predicate-based vector space model.

PubMed

Kwak, Myungjae; Leroy, Gondy; Martinez, Jesse D; Harwell, Jeffrey

2013-10-01

Although biomedical information available in articles and patents is increasing exponentially, we continue to rely on the same information retrieval methods and use very few keywords to search millions of documents. We are developing a fundamentally different approach for finding much more precise and complete information with a single query using predicates instead of keywords for both query and document representation. Predicates are triples that are more complex datastructures than keywords and contain more structured information. To make optimal use of them, we developed a new predicate-based vector space model and query-document similarity function with adjusted tf-idf and boost function. Using a test bed of 107,367 PubMed abstracts, we evaluated the first essential function: retrieving information. Cancer researchers provided 20 realistic queries, for which the top 15 abstracts were retrieved using a predicate-based (new) and keyword-based (baseline) approach. Each abstract was evaluated, double-blind, by cancer researchers on a 0-5 point scale to calculate precision (0 versus higher) and relevance (0-5 score). Precision was significantly higher (p<.001) for the predicate-based (80%) than for the keyword-based (71%) approach. Relevance was almost doubled with the predicate-based approach-2.1 versus 1.6 without rank order adjustment (p<.001) and 1.34 versus 0.98 with rank order adjustment (p<.001) for predicate--versus keyword-based approach respectively. Predicates can support more precise searching than keywords, laying the foundation for rich and sophisticated information search. Copyright © 2013 Elsevier Inc. All rights reserved.

Public hospital quality report awareness: evidence from National and Californian Internet searches and social media mentions, 2012.

PubMed

Huesch, Marco D; Currid-Halkett, Elizabeth; Doctor, Jason N

2014-03-11

Publicly available hospital quality reports seek to inform consumers of important healthcare quality and affordability attributes, and may inform consumer decision-making. To understand how much consumers search for such information online on one Internet search engine, whether they mention such information in social media and how positively they view this information. A leading Internet search engine (Google) was the main focus of the study. Google Trends and Google Adwords keyword analyses were performed for national and Californian searches between 1 August 2012 and 31 July 2013 for keywords related to 'top hospital', best hospital', and 'hospital quality', as well as for six specific hospital quality reports. Separately, a proprietary social media monitoring tool was used to investigate blog, forum, social media and traditional media mentions of, and sentiment towards, major public reports of hospital quality in California in 2012. (1) Counts of searches for keywords performed on Google; (2) counts of and (3) sentiment of mentions of public reports on social media. National Google search volume for 75 hospital quality-related terms averaged 610 700 searches per month with strong variation by keyword and by state. A commercial report (Healthgrades) was more commonly searched for nationally on Google than the federal government's Hospital Compare, which otherwise dominated quality-related search terms. Social media references in California to quality reports were generally few, and commercially produced hospital quality reports were more widely mentioned than state (Office of Statewide Healthcare Planning and Development (OSHPD)), or non-profit (CalHospitalCompare) reports. Consumers are somewhat aware of hospital quality based on Internet search activity and social media disclosures. Public stakeholders may be able to broaden their quality dissemination initiatives by advertising on Google or Twitter and using social media interactively with consumers looking for relevant information.

Publications - PIR 2004-3 | Alaska Division of Geological & Geophysical

Science.gov Websites

) Keywords Alaska, State of; Alluvial Deposits; Amy Creek Assemblage; Amy Dolomite; Ar-Ar; Bison Fossils ; Cambrian; Caribou Fossils; Cascaden Ridge Unit; Cenozoic; Colluvial Deposits; Cretaceous; Devonian ; Engineering Geology; Eolian; Fox Fossils; Geochemistry; Geochronology; Geologic Hazards; Geologic Materials

Using PAFEC as a preprocessor for COSMIC/NASTRAN

NASA Technical Reports Server (NTRS)

Gray, W. H.; Baudry, T. V.

1983-01-01

Programs for Automatic Finite Element Calculations (PAFEC) is a general purpose, three dimensional linear and nonlinear finite element program (ref. 1). PAFEC's features include free format input utilizing engineering keywords, powerful mesh generating facilities, sophisticated data base management procedures, and extensive data validation checks. Presented here is a description of a software interface that permits PAFEC to be used as a preprocessor for COSMIC/NASTRAN. This user friendly software, called PAFCOS, frees the stress analyst from the laborious and error prone procedure of creating and debugging a rigid format COSMIC/NASTRAN bulk data deck. By interactively creating and debugging a finite element model with PAFEC, thus taking full advantage of the free format engineering keyword oriented data structure of PAFEC, the amount of time spent during model generation can be drastically reduced. The PAFCOS software will automatically convert a PAFEC data structure into a COSMIC/NASTRAN bulk data deck. The capabilities and limitations of the PAFCOS software are fully discussed in the following report.

Holocene alluvium around Lefkosia (Nicosia), Cyprus: An archive of land-use, tectonic processes, and climate change

USGS Publications Warehouse

Newell, Wayne L.; Stone, B.; Harrison, R.; ,

2004-01-01

Holocene alluvium of the Pedhicos River around Lefkosia (Nicosia), Cyprus, was studied. Alluvial stratigraphy was found to present serial flood deposits underlying river terraces and an extensive alluvial fan. It was found that the stratigraphy and geomorphology of the alluvium can be interpreted to distinguish not only the effects of climate change, but also land-use change, and the impact of particular engineering works. It was suggested that details of the physical properties of the flood deposit sequences and paleosols can contribute to modeling various geophysical and engineering properties and in predicting response to vertical acceleration during earthquakes.

Fluvio geomorphic set-up of Noctis Fossae in Noctis Labyrinthus of Syria-Planum Provenance, Mars

NASA Astrophysics Data System (ADS)

Chavan, A. A.; Bhandari, S.

2017-12-01

The modern era of planetary exploration has revealed fluvial or fluvial like landforms on the extraterrestrial surfaces of planets and moons of our solar system. This has posed as interesting challenges for advancing our fundamental understanding of fluvial processes and their associated landforms on the planetary surfaces especially on Mars. It has been recognized through earlier studies that the channels and valleys are extensively dissected on Mars. The Valleys are low lying, elongate troughs surrounded by elevated topography. Moreover, valley networks on Mars are the most noticeable features attesting that different geological processes and possibly climatic conditions prevailed in the past and played a vital role in formulating the Martian topography. Channel incisions which are a domino effect both tectonic and surface runoff and groundwater sapping. The components of surface runoff have been deciphered with the help of morphometric exercises. Further, the geomorphological studies of these landforms are critical in understanding the regional tectonics. The present work is an assessment of Fluvio geomorphic set-up of Noctis Fossae in Noctis Labyrinthus of Syria-Planum Provenance, Mars. This study focuses on the fluvio geomorphology of the southern highlands (00 to 400S to 850-1200W) to determine how these features were formed, which process formed these valleys and includes the probable causes resulting into the development of the topography. Keywords: Noctis Fossae; Noctis Labyrinthus; Syria Planum; Mars

Morphotectonic study of the Brahmaputra basin using geoinformatics

NASA Astrophysics Data System (ADS)

Nath Sarma, Jogendra; Acharjee, Shukla; murgante, Beniamino

2013-04-01

The Brahmaputra River basin occupies an area of 580,000 km2 lying in Tibet (China), Bhutan, India and Bangladesh. It is bounded on the north by the Nyen-Chen-Tanghla mountains, on the east by the Salween River basin and Patkari range of hills, on the south by Nepal Himalayas and the Naga Hills and on the west by the Ganga sub-basin. Brahmaputra river originates at an elevation of about 5150 m in south-west Tibet and flows for about 2900 km through Tibet (China), India and Bangladesh to join the Ganga.. The Brahmaputra River basin is investigated to examine the influence of active structures by applying an integrated study on geomorphology, morphotectonics, Digital Elevation Model (DEM) using topographic map, satellite data, SRTM, and seismic data. The indices for morphotectonic analysis, viz. basin elongation ratio (Re) indicated tectonically active, transverse topographic symmetry (T = 0.018-0.664) indicated asymmetric nature, asymmetric factor (AF=33) suggested tilt, valley floor width to valley height ratio (Vf = 0.0013-2.945) indicated active incision and mountain-front sinuosity (Smf = 1.11-1.68) values indicated active tectonics in the area. A great or major earthquake in the modern times, in this region may create havoc with huge loss of life and property due to high population density and rapidly developing infrastructure. Keywords: .Morphotectonic, Brahmaputra river, earthquake

Seeking Health Information Online: Does Wikipedia Matter?

PubMed Central

Laurent, Michaël R.; Vickers, Tim J.

2009-01-01

Objective To determine the significance of the English Wikipedia as a source of online health information. Design The authors measured Wikipedia's ranking on general Internet search engines by entering keywords from MedlinePlus, NHS Direct Online, and the National Organization of Rare Diseases as queries into search engine optimization software. We assessed whether article quality influenced this ranking. The authors tested whether traffic to Wikipedia coincided with epidemiological trends and news of emerging health concerns, and how it compares to MedlinePlus. Measurements Cumulative incidence and average position of Wikipedia® compared to other Web sites among the first 20 results on general Internet search engines (Google®, Google UK®, Yahoo®, and MSN®), and page view statistics for selected Wikipedia articles and MedlinePlus pages. Results Wikipedia ranked among the first ten results in 71–85% of search engines and keywords tested. Wikipedia surpassed MedlinePlus and NHS Direct Online (except for queries from the latter on Google UK), and ranked higher with quality articles. Wikipedia ranked highest for rare diseases, although its incidence in several categories decreased. Page views increased parallel to the occurrence of 20 seasonal disorders and news of three emerging health concerns. Wikipedia articles were viewed more often than MedlinePlus Topic (p = 0.001) but for MedlinePlus Encyclopedia pages, the trend was not significant (p = 0.07–0.10). Conclusions Based on its search engine ranking and page view statistics, the English Wikipedia is a prominent source of online health information compared to the other online health information providers studied. PMID:19390105

AFRPL Rapid Indexing System.

ERIC Educational Resources Information Center

Beltran, Alfred A.

A modified Keyword Out of Context (KWOC) system was developed to gain rapid control over more than 8,000 scattered, unindexed documents. This was the first step in providing the technical information support required by Air Force Rocket Propulsion Laboratory scientists and engineers. Implementation of the KWOC system, computer routines, and…

The Exponential Expansion of Simulation: How Simulation has Grown as a Research Tool

DTIC Science & Technology

2012-09-01

exponential growth of computing power. Although other analytic approaches also benefit from this trend, keyword searches of several scholarly search ... engines reveal that the reliance on simulation is increasing more rapidly. A descriptive analysis paints a compelling picture: simulation is frequently

Quality of Web-Based Information on Cannabis Addiction

ERIC Educational Resources Information Center

Khazaal, Yasser; Chatton, Anne; Cochand, Sophie; Zullino, Daniele

2008-01-01

This study evaluated the quality of Web-based information on cannabis use and addiction and investigated particular content quality indicators. Three keywords ("cannabis addiction," "cannabis dependence," and "cannabis abuse") were entered into two popular World Wide Web search engines. Websites were assessed with a standardized proforma designed…

A systematic literature review of engineering identity: definitions, factors, and interventions affecting development, and means of measurement

NASA Astrophysics Data System (ADS)

Morelock, John R.

2017-11-01

Studies exploring what it means to be an engineer professionally have been conducted for decades, but have boomed in recent years. This systematic literature review aims to organise extant studies on engineering identity by coding around four key variables: (a) definitions of engineering identity, (b) factors affecting engineering identity development, (c) interventions affecting engineering identity development, and (d) means of measuring identity. In doing so, this review provides strategies for future research and educational interventions to advance work related to engineering identity. Publications were selected for inclusion by screening and appraising results obtained from databases and keywords refined through a scoping study. Derived from key findings, suggestions for future research include bridging disparate strands of engineering identity literature and incorporating more varied methodological approaches. Also from key findings, suggestions for future practice involve better connecting existing definitions of engineering identity and factors known to affect identity development with identity-related interventions.

Augmentation cystoplasty in neurogenic bladder

PubMed Central

Kocjancic, Ervin; Demirdağ, Çetin

2016-01-01

The aim of this review is to update the indications, contraindications, technique, complications, and the tissue engineering approaches of augmentation cystoplasty (AC) in patients with neurogenic bladder. PubMed/MEDLINE was searched for the keywords "augmentation cystoplasty," "neurogenic bladder," and "bladder augmentation." Additional relevant literature was determined by examining the reference lists of articles identified through the search. The update review of of the indications, contraindications, technique, outcome, complications, and tissue engineering approaches of AC in patients with neurogenic bladder is presented. Although some important progress has been made in tissue engineering AC, conventional AC still has an important role in the surgical treatment of refractory neurogenic lower urinary tract dysfunction. PMID:27617312

Comparison of Four Search Engines and their efficacy With Emphasis on Literature Research in Addiction (Prevention and Treatment).

PubMed

Samadzadeh, Gholam Reza; Rigi, Tahereh; Ganjali, Ali Reza

2013-01-01

Surveying valuable and most recent information from internet, has become vital for researchers and scholars, because every day, thousands and perhaps millions of scientific works are brought out as digital resources which represented by internet and researchers can't ignore this great resource to find related documents for their literature search, which may not be found in any library. With regard to variety of documents presented on the internet, search engines are one of the most effective search tools for finding information. The aim of this study is to evaluate the three criteria, recall, preciseness and importance of the four search engines which are PubMed, Science Direct, Google Scholar and federated search of Iranian National Medical Digital Library in addiction (prevention and treatment) to select the most effective search engine for offering the best literature research. This research was a cross-sectional study by which four popular search engines in medical sciences were evaluated. To select keywords, medical subject heading (Mesh) was used. We entered given keywords in the search engines and after searching, 10 first entries were evaluated. Direct observation was used as a mean for data collection and they were analyzed by descriptive statistics (number, percent number and mean) and inferential statistics, One way analysis of variance (ANOVA) and post hoc Tukey in Spss. 15 statistical software. P Value < 0.05 was considered statistically significant. Results have shown that the search engines had different operations with regard to the evaluated criteria. Since P Value was 0.004 < 0.05 for preciseness and was 0.002 < 0.05 for importance, it shows significant difference among search engines. PubMed, Science Direct and Google Scholar were the best in recall, preciseness and importance respectively. As literature research is one of the most important stages of research, it's better for researchers, especially Substance-Related Disorders scholars to use different search engines with the best recall, preciseness and importance in that subject field to reach desirable results while searching and they don't depend on just one search engine.

Comparison of Four Search Engines and their efficacy With Emphasis on Literature Research in Addiction (Prevention and Treatment)

PubMed Central

Samadzadeh, Gholam Reza; Rigi, Tahereh; Ganjali, Ali Reza

2013-01-01

Background Surveying valuable and most recent information from internet, has become vital for researchers and scholars, because every day, thousands and perhaps millions of scientific works are brought out as digital resources which represented by internet and researchers can’t ignore this great resource to find related documents for their literature search, which may not be found in any library. With regard to variety of documents presented on the internet, search engines are one of the most effective search tools for finding information. Objectives The aim of this study is to evaluate the three criteria, recall, preciseness and importance of the four search engines which are PubMed, Science Direct, Google Scholar and federated search of Iranian National Medical Digital Library in addiction (prevention and treatment) to select the most effective search engine for offering the best literature research. Materials and Methods This research was a cross-sectional study by which four popular search engines in medical sciences were evaluated. To select keywords, medical subject heading (Mesh) was used. We entered given keywords in the search engines and after searching, 10 first entries were evaluated. Direct observation was used as a mean for data collection and they were analyzed by descriptive statistics (number, percent number and mean) and inferential statistics, One way analysis of variance (ANOVA) and post hoc Tukey in Spss. 15 statistical software. P Value < 0.05 was considered statistically significant. Results Results have shown that the search engines had different operations with regard to the evaluated criteria. Since P Value was 0.004 < 0.05 for preciseness and was 0.002 < 0.05 for importance, it shows significant difference among search engines. PubMed, Science Direct and Google Scholar were the best in recall, preciseness and importance respectively. Conclusions As literature research is one of the most important stages of research, it's better for researchers, especially Substance-Related Disorders scholars to use different search engines with the best recall, preciseness and importance in that subject field to reach desirable results while searching and they don’t depend on just one search engine. PMID:24971257

GoWeb: a semantic search engine for the life science web.

PubMed

Dietze, Heiko; Schroeder, Michael

2009-10-01

Current search engines are keyword-based. Semantic technologies promise a next generation of semantic search engines, which will be able to answer questions. Current approaches either apply natural language processing to unstructured text or they assume the existence of structured statements over which they can reason. Here, we introduce a third approach, GoWeb, which combines classical keyword-based Web search with text-mining and ontologies to navigate large results sets and facilitate question answering. We evaluate GoWeb on three benchmarks of questions on genes and functions, on symptoms and diseases, and on proteins and diseases. The first benchmark is based on the BioCreAtivE 1 Task 2 and links 457 gene names with 1352 functions. GoWeb finds 58% of the functional GeneOntology annotations. The second benchmark is based on 26 case reports and links symptoms with diseases. GoWeb achieves 77% success rate improving an existing approach by nearly 20%. The third benchmark is based on 28 questions in the TREC genomics challenge and links proteins to diseases. GoWeb achieves a success rate of 79%. GoWeb's combination of classical Web search with text-mining and ontologies is a first step towards answering questions in the biomedical domain. GoWeb is online at: http://www.gopubmed.org/goweb.

The contribution of engineering surveys by means of GPS to the determination of crustal movements in Istanbul

NASA Astrophysics Data System (ADS)

Özyaşar, M.; Özlüdemir, M. T.

2011-06-01

Global Navigation Satellite Systems (GNSS) are space based positioning techniques and widely used in geodetic applications. Geodetic networking accomplished by engineering surveys constitutes one of these tasks. Geodetic networks are used as the base of all kinds of geodetic implementations, Co from the cadastral plans to the relevant surveying processes during the realization of engineering applications. Geodetic networks consist of control points positioned in a defined reference frame. In fact, such positional information could be useful for other studies as well. One of such fields is geodynamic studies that use the changes of positions of control stations within a network in a certain time period to understand the characteristics of tectonic movements. In Turkey, which is located in tectonically active zones and struck by major earthquakes quite frequently, the positional information obtained in engineering surveys could be very useful for earthquake related studies. For this purpose, a GPS (Global Positioning System) network of 650 stations distributed over Istanbul (Istanbul GPS Triangulation Network; abbreviated IGNA) covering the northern part of the North Anatolian Fault Zone (NAFZ) was established in 1997 and measured in 1999. From 1998 to 2004, the IGNA network was extended to 1888 stations covering an area of about 6000 km2, the whole administration area of Istanbul. All 1888 stations within the IGNA network were remeasured in 2005. In these two campaigns there existed 452 common points, and between these two campaigns two major earthquakes took place, on 17 August and 12 November 1999 with a Richter scale magnitude of 7.4 and 7.2, respectively. Several studies conducted for estimating the horizontal and vertical displacements as a result of these earthquakes on NAFZ are discussed in this paper. In geodynamic projects carried out before the earthquakes in 1999, an annual average velocity of 2-2.5 cm for the stations along the NAFZ were estimated. Studies carried out using GPS observations in the same area after these earthquakes indicated that point displacements vary depending on their distance to the epicentres of the earthquakes. But the directions of point displacements are similar. The results obtained through the analysis of the IGNA network also show that there is a common trend in the directions of point displacements in the study area. In this paper, the past studies about the tectonics of Marmara region are summarised and the results of the displacement analysis on the IGNA network are discussed.

Determining Studies Conducted upon Individuals with Autism Spectrum Disorder Using High-Tech Devices

ERIC Educational Resources Information Center

Eliçin, Özge; Kaya, Ali

2017-01-01

This study explores 67 experimental research articles written about children with Autism Spectrum Disorder using high-tech devices. The studies in this research were accessed through EBSCO, Academic Search Complete, ERIC, and Uludag University online search engines using keywords such as "autism and technology", "autism and…

An Analytical Index to the Internet: Dreams of Utopia.

ERIC Educational Resources Information Center

Casey, Carol

1999-01-01

Explores the need for analytical indexes to access Internet resources. Considers bibliographic control, Web site design, keyword search engines, hierarchical subject indexes, and special indexes and compilations of links, and concludes that the creation of small, focused indexes may be the best solution for accessing specific types of digital…

Publications - PDF 99-24C | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska :63,360 (6.7 M) Keywords Geologic Map; Geology; Geomorphology; Glacial; STATEMAP Project; Slope Instability; Surficial; Surficial Geologic Map; Surficial Geology Top of Page Department of Natural Resources

Publications - PDF 99-24A | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Alaska, scale 1:63,360 (6.9 M) Keywords Ar-Ar; Bedrock; Bedrock Geology; Generalized; Geologic; Geologic Map; Geology; Gold; Lode; Non-Metals; Paleontology; Plutonic; Plutonic Hosted; STATEMAP Project

Publications - PDF 96-16 | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska fbx_prelim_geology Shapefile 6.5 M Metadata - Read me Keywords Age Dates; Antimony; Ar-Ar; Bedrock; Bedrock Geology ; Birch Hill Sequence; Bismuth; Chatanika Terrane; Construction Materials; Derivative; Economic Geology

Using JournalMap to link spatial information with ecological site descriptions

USDA-ARS?s Scientific Manuscript database

JournalMap is a scientific literature search engine that empowers you to find relevant research based on location and biophysical variables as well as traditional keyword searches. All publications are geotagged based on reported location information and plotted on a world map showing where the rese...

Specialized medical search-engines are no better than general search-engines in sourcing consumer information about androgen deficiency.

PubMed

Ilic, D; Bessell, T L; Silagy, C A; Green, S

2003-03-01

The Internet provides consumers with access to online health information; however, identifying relevant and valid information can be problematic. Our objectives were firstly to investigate the efficiency of search-engines, and then to assess the quality of online information pertaining to androgen deficiency in the ageing male (ADAM). Keyword searches were performed on nine search-engines (four general and five medical) to identify website information regarding ADAM. Search-engine efficiency was compared by percentage of relevant websites obtained via each search-engine. The quality of information published on each website was assessed using the DISCERN rating tool. Of 4927 websites searched, 47 (1.44%) and 10 (0.60%) relevant websites were identified by general and medical search-engines respectively. The overall quality of online information on ADAM was poor. The quality of websites retrieved using medical search-engines did not differ significantly from those retrieved by general search-engines. Despite the poor quality of online information relating to ADAM, it is evident that medical search-engines are no better than general search-engines in sourcing consumer information relevant to ADAM.

Tectonic creep in the Hayward fault zone, California

USGS Publications Warehouse

Radbruch-Hall, Dorothy H.; Bonilla, M.G.

1966-01-01

Tectonic creep is slight apparently continuous movement along a fault. Evidence of creep has been noted at several places within the Hayward fault zone--a zone trending northwestward near the western front of the hills bordering the east side of San Francisco Bay. D. H. Radbruch of the Geological Survey and B. J. Lennert, consulting engineer, confirmed a reported cracking of a culvert under the University of California stadium. F. B. Blanchard and C. L. Laverty of the East Bay Municipal Utility District of Oakland studied cracks in the Claremont water tunnel in Berkeley. M. G. Bonilla of the Geological Survey noted deformation of railroad tracks in the Niles district of Fremont. Six sets of tracks have been bent and shifted. L. S. Cluff of Woodward-Clyde-Sherard and Associates and K. V. Steinbrugge of the Pacific Fire Rating Bureau noted that the concrete walls of a warehouse in the Irvington district of Fremont have been bent and broken, and the columns forced out of line. All the deformations noted have been right lateral and range from about 2 inches in the Claremont tunnel to about 8 inches on the railroad tracks. Tectonic creep almost certainly will continue to damage buildings, tunnels, and other structures that cross the narrow bands of active movement within the Hayward fault zone.

Basics of applied geothermal engineering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wehlage, E.F.

1976-01-01

The following chapters are included: (1) born of fire, (2) milestones with tectonics, (3) a world in geothermal review, (4) simple mechanical and electrical facts for geothermal, (5) elementary hydraulics and pumping, (6) elementary heat, (7) application of steam, (8) geothermal hydroponics, (9) designing for a geothermal diary, (10) review of geothermal prime movers for power production, (11) design procedures-geothermal house heating, (12) cooling with geothermal refrigeration, and (13) geothermal synthesis-new heat for the world. (MOW)

Research in Biomaterials and Tissue Engineering: Achievements and perspectives.

PubMed

Ventre, Maurizio; Causa, Filippo; Netti, Paolo A; Pietrabissa, Riccardo

2015-01-01

Research on biomaterials and related subjects has been active in Italy. Starting from the very first examples of biomaterials and biomedical devices, Italian researchers have always provided valuable scientific contributions. This trend has steadily increased. To provide a rough estimate of this, it is sufficient to search PubMed, a free search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics, with the keywords "biomaterials" or "tissue engineering" and sort the results by affiliation. Again, even though this is a crude estimate, the results speak for themselves, as Italy is the third European country, in terms of publications, with an astonishing 3,700 products in the last decade.

Blended Learning, E-Learning and Mobile Learning in Mathematics Education

ERIC Educational Resources Information Center

Borba, Marcelo C.; Askar, Petek; Engelbrecht, Johann; Gadanidis, George; Llinares, Salvador; Aguilar, Mario Sánchez

2016-01-01

In this literature survey we focus on identifying recent advances in research on digital technology in the field of mathematics education. To conduct the survey we have used internet search engines with keywords related to mathematics education and digital technology and have reviewed some of the main international journals, including the ones in…

Reviewing Instructional Studies Conducted Using Video Modeling to Children with Autism

ERIC Educational Resources Information Center

Acar, Cimen; Diken, Ibrahim H.

2012-01-01

This study explored 31 instructional research articles written using video modeling to children with autism and published in peer-reviewed journals. The studies in this research have been reached by searching EBSCO, Academic Search Complete, ERIC and other Anadolu University online search engines and using keywords such as "autism, video modeling,…

Publications - PDF 99-24B | Alaska Division of Geological & Geophysical

Science.gov Websites

Alaska's Mineral Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska (6.4 M) Keywords Ar-Ar; Bedrock; Bedrock Geologic Map; Bedrock Geology; Economic Geology; Geochronology ; Geologic; Geologic Map; Geology; Gold; Lode; Plutonic; Plutonic Hosted; Porphyry; STATEMAP Project; Silver

Mechanism of Earth Fissures in Beijing,China

NASA Astrophysics Data System (ADS)

Zhang, Y.; Gong, H.; Gu, Z.; Wang, R.; Jia, S.; Li, X.

2013-12-01

Earth fissure is one of the natural hazards that can occur due to different mechanisms. The Beijing city, located in the north of North China Plain, China, has undergone extensive fissuring for the last twenty years. These fissures have caused serious damages to homes, farmlands and infrastructures. The previous investigation shows the distribution and direction of the major earth fissures mostly paralleled to the active fault, such as Huangzhuang-Gaoliying Fault. Hence, tectonic movements were thought to be the major cause of the fissuring in this region. But the subsidence caused by overdraft and other geological, hydrological and mechanical factors may also play important roles in forming earth fissure. The purpose of the work was to further explores the reason for the cause of the earth fissures and their mechanism of formations using field investigations, geophysical surveys, geotechnical tests and numerical analysis. The results indicated that over-extraction groundwater and differential subsidence are the major causes of the fissuring. The active faulting and fault zone provided or created an ideal condition for stress to accumulate. The earth fissures occur at times when the accumulated stress exceed the strength of soil or coupled with other process by which the strength of soil material is reduced. Survey and simulated results reveal the complex pattern of earth fissure including tensile deformation, vertical offset and rotation. The potential locations for future damage were also evaluated. Keywords: Earth Fissure; Mechanism; Beijing; Subsidence; tectonic movement; Geophysical survey

Public hospital quality report awareness: evidence from National and Californian Internet searches and social media mentions, 2012

PubMed Central

Huesch, Marco D; Currid-Halkett, Elizabeth; Doctor, Jason N

2014-01-01

Objectives Publicly available hospital quality reports seek to inform consumers of important healthcare quality and affordability attributes, and may inform consumer decision-making. To understand how much consumers search for such information online on one Internet search engine, whether they mention such information in social media and how positively they view this information. Setting and design A leading Internet search engine (Google) was the main focus of the study. Google Trends and Google Adwords keyword analyses were performed for national and Californian searches between 1 August 2012 and 31 July 2013 for keywords related to ‘top hospital’, best hospital’, and ‘hospital quality’, as well as for six specific hospital quality reports. Separately, a proprietary social media monitoring tool was used to investigate blog, forum, social media and traditional media mentions of, and sentiment towards, major public reports of hospital quality in California in 2012. Primary outcome measures (1) Counts of searches for keywords performed on Google; (2) counts of and (3) sentiment of mentions of public reports on social media. Results National Google search volume for 75 hospital quality-related terms averaged 610 700 searches per month with strong variation by keyword and by state. A commercial report (Healthgrades) was more commonly searched for nationally on Google than the federal government's Hospital Compare, which otherwise dominated quality-related search terms. Social media references in California to quality reports were generally few, and commercially produced hospital quality reports were more widely mentioned than state (Office of Statewide Healthcare Planning and Development (OSHPD)), or non-profit (CalHospitalCompare) reports. Conclusions Consumers are somewhat aware of hospital quality based on Internet search activity and social media disclosures. Public stakeholders may be able to broaden their quality dissemination initiatives by advertising on Google or Twitter and using social media interactively with consumers looking for relevant information. PMID:24618223

Development of a One-Stop Data Search and Discovery Engine using Ontologies for Semantic Mappings (HydroSeek)

NASA Astrophysics Data System (ADS)

Piasecki, M.; Beran, B.

2007-12-01

Search engines have changed the way we see the Internet. The ability to find the information by just typing in keywords was a big contribution to the overall web experience. While the conventional search engine methodology worked well for textual documents, locating scientific data remains a problem since they are stored in databases not readily accessible by search engine bots. Considering different temporal, spatial and thematic coverage of different databases, especially for interdisciplinary research it is typically necessary to work with multiple data sources. These sources can be federal agencies which generally offer national coverage or regional sources which cover a smaller area with higher detail. However for a given geographic area of interest there often exists more than one database with relevant data. Thus being able to query multiple databases simultaneously is a desirable feature that would be tremendously useful for scientists. Development of such a search engine requires dealing with various heterogeneity issues. In scientific databases, systems often impose controlled vocabularies which ensure that they are generally homogeneous within themselves but are semantically heterogeneous when moving between different databases. This defines the boundaries of possible semantic related problems making it easier to solve than with the conventional search engines that deal with free text. We have developed a search engine that enables querying multiple data sources simultaneously and returns data in a standardized output despite the aforementioned heterogeneity issues between the underlying systems. This application relies mainly on metadata catalogs or indexing databases, ontologies and webservices with virtual globe and AJAX technologies for the graphical user interface. Users can trigger a search of dozens of different parameters over hundreds of thousands of stations from multiple agencies by providing a keyword, a spatial extent, i.e. a bounding box, and a temporal bracket. As part of this development we have also added an environment that allows users to do some of the semantic tagging, i.e. the linkage of a variable name (which can be anything they desire) to defined concepts in the ontology structure which in turn provides the backbone of the search engine.

Macro- and micro- geodynamic of Terebliya-Riksk geodetic man-caused polygon of Ukrainian Carpathians influenced by specificities of structure-geological and hydro-geological conditions

NASA Astrophysics Data System (ADS)

Kulchyzkyy, A.; Serebryannyy, Y.; Tretyak, K.; Trevogo, I.; Zadoroznnyy, V.

2009-04-01

Terebliya-Riksk diversion power station is located on two levels ( with difference of 180m ) of south mountainside of Ukrainian Carpathians and separate parts of this power station lie inside rock. Therefore influential parameters of it's stability are geological, tectonic and hydrogeological conditions in complex. Monitoring of intensity and nature of displacements of flow ( pressure) pipe and other objects of power station with geoditic methods indicates that fluctuations of water-level in reservoir caused bouth by natural and artificial efects are of great influence on objects mentioned. Based on geodetical high-precision observations made by LeicaTPS 1201 robotic total station short-periodic components of fundamental vibrations which result in their destructive deformation were determined. Mathematical apparatus ( which uses function of Fourie series and theory of cinematic coefficients ) for displacements determinations of pressure pipe was disigned. Complex of engineering-geological surveys gave an opportunity to define the origin of macro- and micro- geodynamics movements of Terebliya-Riksk diversion power station region. Engineering-geological conditions which influence on power station structure most of all were determined as following : small foldings and cleavage areas appearances, also fluctuations of level of underground water (refered to hydrogeological conditions). Periodic micro-displacemets appearances ( which operate on reducing-stretching scheme) fixed on power station structure are turned to be in direct relation on to what exend reservoir is filled up. Permanent macro- displacements appearances ( which operates in north-west direction ) fixed on pressure pipe are the result sum of residual micro-displacements caused by return periodic movements and are determined by structure-geological, engineering-geological and tectonic conditions.

An end user evaluation of query formulation and results review tools in three medical meta-search engines.

PubMed

Leroy, Gondy; Xu, Jennifer; Chung, Wingyan; Eggers, Shauna; Chen, Hsinchun

2007-01-01

Retrieving sufficient relevant information online is difficult for many people because they use too few keywords to search and search engines do not provide many support tools. To further complicate the search, users often ignore support tools when available. Our goal is to evaluate in a realistic setting when users use support tools and how they perceive these tools. We compared three medical search engines with support tools that require more or less effort from users to form a query and evaluate results. We carried out an end user study with 23 users who were asked to find information, i.e., subtopics and supporting abstracts, for a given theme. We used a balanced within-subjects design and report on the effectiveness, efficiency and usability of the support tools from the end user perspective. We found significant differences in efficiency but did not find significant differences in effectiveness between the three search engines. Dynamic user support tools requiring less effort led to higher efficiency. Fewer searches were needed and more documents were found per search when both query reformulation and result review tools dynamically adjust to the user query. The query reformulation tool that provided a long list of keywords, dynamically adjusted to the user query, was used most often and led to more subtopics. As hypothesized, the dynamic result review tools were used more often and led to more subtopics than static ones. These results were corroborated by the usability questionnaires, which showed that support tools that dynamically optimize output were preferred.

Automating Information Discovery Within the Invisible Web

NASA Astrophysics Data System (ADS)

Sweeney, Edwina; Curran, Kevin; Xie, Ermai

A Web crawler or spider crawls through the Web looking for pages to index, and when it locates a new page it passes the page on to an indexer. The indexer identifies links, keywords, and other content and stores these within its database. This database is searched by entering keywords through an interface and suitable Web pages are returned in a results page in the form of hyperlinks accompanied by short descriptions. The Web, however, is increasingly moving away from being a collection of documents to a multidimensional repository for sounds, images, audio, and other formats. This is leading to a situation where certain parts of the Web are invisible or hidden. The term known as the "Deep Web" has emerged to refer to the mass of information that can be accessed via the Web but cannot be indexed by conventional search engines. The concept of the Deep Web makes searches quite complex for search engines. Google states that the claim that conventional search engines cannot find such documents as PDFs, Word, PowerPoint, Excel, or any non-HTML page is not fully accurate and steps have been taken to address this problem by implementing procedures to search items such as academic publications, news, blogs, videos, books, and real-time information. However, Google still only provides access to a fraction of the Deep Web. This chapter explores the Deep Web and the current tools available in accessing it.

Internet-based information-seeking behavior for transient ischemic attack.

PubMed

Abedi, Vida; Mbaye, Marieme; Tsivgoulis, Georgios; Male, Shailesh; Goyal, Nitin; Alexandrov, Andrei V; Zand, Ramin

2015-12-01

In recent years, Internet became an increasingly important tool for accessing health information and is being used more frequently to promote public health. To use Google search data to explore information seeking behavior for transient ischemic attack. We selected two groups of keywords related to transient ischemic attack: 'Transient Ischemic Attack' and 'Mini Stroke'. We obtained all available online search data performed in the United States from the Google search engine for a 10-year span--January 2004 to December 2013. The monthly and daily search data for the selected keywords were analyzed--using moving average--to explore the trends, peaks, and declining effects. There were three significant concurrent peaks in the Google search data for the selected keywords. Each peak was directly associated with media coverage and news headlines related to the incident of transient ischemic attack in a public figure. Following each event, it took three- to seven-days for the search trend to return to its respective average value. Furthermore, the trend was steady for 'Transient Ischemic Attack'; however, the search interest for the keyword 'Mini Stroke' shows a steady increase. The overall search interest for the selected keywords was significantly higher in the southeastern United States. Our study shows that changes in online search behavior can be associated with media coverage of key events (in our case transient ischemic attack) in public figures. These findings suggest that multimedia health promotion campaigns might be more effective, if increased promptly after similar media coverage. © 2015 World Stroke Organization.

Designing a Syntax-Based Retrieval System for Supporting Language Learning

ERIC Educational Resources Information Center

Tsao, Nai-Lung; Kuo, Chin-Hwa; Wible, David; Hung, Tsung-Fu

2009-01-01

In this paper, we propose a syntax-based text retrieval system for on-line language learning and use a fast regular expression search engine as its main component. Regular expression searches provide more scalable querying and search results than keyword-based searches. However, without a well-designed index scheme, the execution time of regular…

"Google Reigns Triumphant"?: Stemming the Tide of Googlitis via Collaborative, Situated Information Literacy Instruction

ERIC Educational Resources Information Center

Leibiger, Carol A.

2011-01-01

Googlitis, the overreliance on search engines for research and the resulting development of poor searching skills, is a recognized problem among today's students. Google is not an effective research tool because, in addition to encouraging keyword searching at the expense of more powerful subject searching, it only accesses the Surface Web and is…

Comparative analysis of student self-reflections on course projects

NASA Astrophysics Data System (ADS)

Pomales-García, Cristina; Cortés Barreto, Kenneth

2014-11-01

This study presents the skills, experiences, and values identified in project self-reflections of 161 undergraduate engineering students. Self-reflections from two different engineering design courses, which provide experiences in project-based learning (PBL), are analysed through the content analysis methodology. Results show that 'application', 'true life', 'satisfaction', and 'communication' are the common keywords shared in the reflections. Multiple hypothesis tests to identify differences between courses, project types, years, and gender suggest that there are no significant differences between experiences, skills, and values self-reported by students who completed either a case study or an industry project. Based on research findings, recommendations will be provided to enhance the engineering curriculum based on PBL experiences to support the development of relevant professional skills and experiences.

Review of Maxillary Expansion Appliance Activation Methods: Engineering and Clinical Perspectives

PubMed Central

Romanyk, D. L.; Lagravere, M. O.; Toogood, R. W.; Major, P. W.; Carey, J. P.

2010-01-01

Objective. Review the reported activation methods of maxillary expansion devices for midpalatal suture separation from an engineering perspective and suggest areas of improvement. Materials and Methods. A literature search of Scopus and PubMed was used to determine current expansion methods. A U.S. and Canadian patent database search was also conducted using patent classification and keywords. Any paper presenting a new method of expansion was included. Results. Expansion methods in use, or patented, can be classified as either a screw- or spring-type, magnetic, or shape memory alloy expansion appliance. Conclusions. Each activation method presented unique advantages and disadvantages from both clinical and engineering perspectives. Areas for improvement still remain and are identified in the paper. PMID:20948570

Using Internet Search Engines to Obtain Medical Information: A Comparative Study

PubMed Central

Wang, Liupu; Wang, Juexin; Wang, Michael; Li, Yong; Liang, Yanchun

2012-01-01

Background The Internet has become one of the most important means to obtain health and medical information. It is often the first step in checking for basic information about a disease and its treatment. The search results are often useful to general users. Various search engines such as Google, Yahoo!, Bing, and Ask.com can play an important role in obtaining medical information for both medical professionals and lay people. However, the usability and effectiveness of various search engines for medical information have not been comprehensively compared and evaluated. Objective To compare major Internet search engines in their usability of obtaining medical and health information. Methods We applied usability testing as a software engineering technique and a standard industry practice to compare the four major search engines (Google, Yahoo!, Bing, and Ask.com) in obtaining health and medical information. For this purpose, we searched the keyword breast cancer in Google, Yahoo!, Bing, and Ask.com and saved the results of the top 200 links from each search engine. We combined nonredundant links from the four search engines and gave them to volunteer users in an alphabetical order. The volunteer users evaluated the websites and scored each website from 0 to 10 (lowest to highest) based on the usefulness of the content relevant to breast cancer. A medical expert identified six well-known websites related to breast cancer in advance as standards. We also used five keywords associated with breast cancer defined in the latest release of Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT) and analyzed their occurrence in the websites. Results Each search engine provided rich information related to breast cancer in the search results. All six standard websites were among the top 30 in search results of all four search engines. Google had the best search validity (in terms of whether a website could be opened), followed by Bing, Ask.com, and Yahoo!. The search results highly overlapped between the search engines, and the overlap between any two search engines was about half or more. On the other hand, each search engine emphasized various types of content differently. In terms of user satisfaction analysis, volunteer users scored Bing the highest for its usefulness, followed by Yahoo!, Google, and Ask.com. Conclusions Google, Yahoo!, Bing, and Ask.com are by and large effective search engines for helping lay users get health and medical information. Nevertheless, the current ranking methods have some pitfalls and there is room for improvement to help users get more accurate and useful information. We suggest that search engine users explore multiple search engines to search different types of health information and medical knowledge for their own needs and get a professional consultation if necessary. PMID:22672889

Using Internet search engines to obtain medical information: a comparative study.

PubMed

Wang, Liupu; Wang, Juexin; Wang, Michael; Li, Yong; Liang, Yanchun; Xu, Dong

2012-05-16

The Internet has become one of the most important means to obtain health and medical information. It is often the first step in checking for basic information about a disease and its treatment. The search results are often useful to general users. Various search engines such as Google, Yahoo!, Bing, and Ask.com can play an important role in obtaining medical information for both medical professionals and lay people. However, the usability and effectiveness of various search engines for medical information have not been comprehensively compared and evaluated. To compare major Internet search engines in their usability of obtaining medical and health information. We applied usability testing as a software engineering technique and a standard industry practice to compare the four major search engines (Google, Yahoo!, Bing, and Ask.com) in obtaining health and medical information. For this purpose, we searched the keyword breast cancer in Google, Yahoo!, Bing, and Ask.com and saved the results of the top 200 links from each search engine. We combined nonredundant links from the four search engines and gave them to volunteer users in an alphabetical order. The volunteer users evaluated the websites and scored each website from 0 to 10 (lowest to highest) based on the usefulness of the content relevant to breast cancer. A medical expert identified six well-known websites related to breast cancer in advance as standards. We also used five keywords associated with breast cancer defined in the latest release of Systematized Nomenclature of Medicine-Clinical Terms (SNOMED CT) and analyzed their occurrence in the websites. Each search engine provided rich information related to breast cancer in the search results. All six standard websites were among the top 30 in search results of all four search engines. Google had the best search validity (in terms of whether a website could be opened), followed by Bing, Ask.com, and Yahoo!. The search results highly overlapped between the search engines, and the overlap between any two search engines was about half or more. On the other hand, each search engine emphasized various types of content differently. In terms of user satisfaction analysis, volunteer users scored Bing the highest for its usefulness, followed by Yahoo!, Google, and Ask.com. Google, Yahoo!, Bing, and Ask.com are by and large effective search engines for helping lay users get health and medical information. Nevertheless, the current ranking methods have some pitfalls and there is room for improvement to help users get more accurate and useful information. We suggest that search engine users explore multiple search engines to search different types of health information and medical knowledge for their own needs and get a professional consultation if necessary.

A bibliography of literature pertaining to plague (Yersinia pestis)

USGS Publications Warehouse

Ellison, Laura E.; Frank, Megan K. Eberhardt

2011-01-01

Plague is an acute and often fatal zoonotic disease caused by the bacterium Yersinia pestis. Y. pestis mainly cycles between small mammals and their fleas; however, it has the potential to infect humans and frequently causes fatalities if left untreated. It is often considered a disease of the past; however, since the late 1800s, plagueis geographic range has expanded greatly, posing new threats in previously unaffected regions of the world, including the Western United States. A literature search was conducted using Internet resources and databases. The keywords chosen for the searches included plague, Yersinia pestis, management, control, wildlife, prairie dogs, fleas, North America, and mammals. Keywords were used alone or in combination with the other terms. Although this search pertains mostly to North America, citations were included from the international research community, as well. Databases and search engines used included Google (http://www.google.com), Google Scholar (http://scholar.google.com), SciVerse Scopus (http://www.scopus.com), ISI Web of Knowledge (http://apps.isiknowledge.com), and the USGS Library's Digital Desktop (http://library.usgs.gov). The literature-cited sections of manuscripts obtained from keyword searches were cross-referenced to identify additional citations or gray literature that was missed by the Internet search engines. This Open-File Report, published as an Internet-accessible bibliography, is intended to be periodically updated with new citations or older references that may have been missed during this compilation. Hence, the authors would be grateful to receive notice of any new or old papers that the audience (users) think need to be included.

A Method for Efficient Searching at Online Shopping

NASA Astrophysics Data System (ADS)

Sanjo, Tomomi; Nagata, Moiro

In recent years, online shopping has been popularized. However, the users can not find efficiently their items at on-line markets. This paper proposes an engine to find items easily at the online market. This engine has the following facilities. First, it presents information in a fixed format. Second, the user can find items by selected keywords. Third, it presents only necessary information by using his/her history. Finally, it has a customize function for each user. Moreover, the system asks the users to down load a page of recommended items. We show the effectives of our proposal with some experiments.

Optimization of OSPF Routing in IP Networks

NASA Astrophysics Data System (ADS)

Bley, Andreas; Fortz, Bernard; Gourdin, Eric; Holmberg, Kaj; Klopfenstein, Olivier; Pióro, Michał; Tomaszewski, Artur; Ümit, Hakan

The Internet is a huge world-wide packet switching network comprised of more than 13,000 distinct subnetworks, referred to as Autonomous Systems (ASs) autonomous system AS . They all rely on the Internet Protocol (IP) internet protocol IP for transport of packets across the network. And most of them use shortest path routing protocols shortest path routing!protocols , such as OSPF or IS-IS, to control the routing of IP packets routing!of IP packets within an AS. The idea of the routing is extremely simple — every packet is forwarded on IP links along the shortest route between its source and destination nodes of the AS. The AS network administrator can manage the routing of packets in the AS by supplying the so-called administrative weights of IP links, which specify the link lengths that are used by the routing protocols for their shortest path computations. The main advantage of the shortest path routing policy is its simplicity, allowing for little administrative overhead. From the network engineering perspective, however, shortest path routing can pose problems in achieving satisfactory traffic handling efficiency. As all routing paths depend on the same routing metric routing!metric , it is not possible to configure the routing paths for the communication demands between different pairs of nodes explicitly or individually; the routing can be controlled only indirectly and only as a whole by modifying the routing metric. Thus, one of the main tasks when planning such networks is to find administrative link weights that induce a globally efficient traffic routing traffic!routing configuration of an AS. It turns out that this task leads to very difficult mathematical optimization problems. In this chapter, we discuss and describe exact integer programming models and solution approaches as well as practically efficient smart heuristics for such shortest path routing problems shortest path routing!problems .

High Performance Pillared Vanadium Oxide Cathode for Lithium Ion Batteries

DTIC Science & Technology

2015-04-24

As a result, two major approaches have been taken to increase electrode- electrolyte interfacial area while minimizing lithium diffusion lengths...Performance Pillared Vanadium Oxide Cathode for Lithium Ion Batteries Siu on Tung, Krista L. Hawthorne, Yi Ding, James Mainero, and Levi T. Thompson...Automotive Research Development and Engineering Center, Warren, MI 48387, USA Keywords: nanostructured materials, lithium ion batteries, cathode

Designing to Support Command and Control in Urban Firefighting

DTIC Science & Technology

2008-06-01

complex human- machine systems. Keywords: Command and control, firefighting, cognitive systems engineering, cognitive task analysis 1...Elm, W. (2000). Bootstrapping multiple converging cognitive task analysis techniques for system design. In J.M.C. Schraagen, S.F. Chipman, & V.L...Shalin, (Eds.), Cognitive Task Analysis . (pp. 317-340). Mahwah, NJ: Lawrence Erlbaum. Rasmussen, J., Pejtersen, A., Goodman, L. (1994). Cognitive

Trends of Serious Games Research from 2007 to 2017: A Bibliometric Analysis

ERIC Educational Resources Information Center

Çiftci, Serdar

2018-01-01

This study examines the tendencies of studies carried out using text mining methods under the title of "serious game". A query was run for the "serious game" keyword in the Web of Science search engine to acquire the data. The study included publications that were scanned in the SCI-EXPANDED, SSCI and A&HCI indices between…

Institutional Repositories in the UK: What Can the Google User Find There?

ERIC Educational Resources Information Center

Markland, Margaret

2006-01-01

This study investigates the efficiency of the Google search engine at retrieving items from 26 UK Institutional Repositories, covering a wide range of subject areas. One item is chosen from each repository and four searches are carried out: two keyword searches and two full title searches, each using both Google and then Google Scholar. A further…

Wireless Sensor Network Radio Power Management and Simulation Models

DTIC Science & Technology

2010-01-01

The Open Electrical & Electronic Engineering Journal, 2010, 4, 21-31 21 1874-1290/10 2010 Bentham Open Open Access Wireless Sensor Network Radio...Air Force Institute of Technology, Wright-Patterson AFB, OH, USA Abstract: Wireless sensor networks (WSNs) create a new frontier in collecting and...consumption. Keywords: Wireless sensor network , power management, energy-efficiency, medium access control (MAC), simulation pa- rameters. 1

Predicting user click behaviour in search engine advertisements

NASA Astrophysics Data System (ADS)

Daryaie Zanjani, Mohammad; Khadivi, Shahram

2015-10-01

According to the specific requirements and interests of users, search engines select and display advertisements that match user needs and have higher probability of attracting users' attention based on their previous search history. New objects such as user, advertisement or query cause a deterioration of precision in targeted advertising due to their lack of history. This article surveys this challenge. In the case of new objects, we first extract similar observed objects to the new object and then we use their history as the history of new object. Similarity between objects is measured based on correlation, which is a relation between user and advertisement when the advertisement is displayed to the user. This method is used for all objects, so it has helped us to accurately select relevant advertisements for users' queries. In our proposed model, we assume that similar users behave in a similar manner. We find that users with few queries are similar to new users. We will show that correlation between users and advertisements' keywords is high. Thus, users who pay attention to advertisements' keywords, click similar advertisements. In addition, users who pay attention to specific brand names might have similar behaviours too.

System Engineering of Photonic Systems for Space Application

NASA Technical Reports Server (NTRS)

Watson, Michael D.; Pryor, Jonathan E.

2014-01-01

The application of photonics in space systems requires tight integration with the spacecraft systems to ensure accurate operation. This requires some detailed and specific system engineering to properly incorporate the photonics into the spacecraft architecture and to guide the spacecraft architecture in supporting the photonics devices. Recent research in product focused, elegant system engineering has led to a system approach which provides a robust approach to this integration. Focusing on the mission application and the integration of the spacecraft system physics incorporation of the photonics can be efficiently and effectively accomplished. This requires a clear understanding of the driving physics properties of the photonics device to ensure proper integration with no unintended consequences. The driving physics considerations in terms of optical performance will be identified for their use in system integration. Keywords: System Engineering, Optical Transfer Function, Optical Physics, Photonics, Image Jitter, Launch Vehicle, System Integration, Organizational Interaction

PIRIA: a general tool for indexing, search, and retrieval of multimedia content

NASA Astrophysics Data System (ADS)

Joint, Magali; Moellic, Pierre-Alain; Hede, P.; Adam, P.

2004-05-01

The Internet is a continuously expanding source of multimedia content and information. There are many products in development to search, retrieve, and understand multimedia content. But most of the current image search/retrieval engines, rely on a image database manually pre-indexed with keywords. Computers are still powerless to understand the semantic meaning of still or animated image content. Piria (Program for the Indexing and Research of Images by Affinity), the search engine we have developed brings this possibility closer to reality. Piria is a novel search engine that uses the query by example method. A user query is submitted to the system, which then returns a list of images ranked by similarity, obtained by a metric distance that operates on every indexed image signature. These indexed images are compared according to several different classifiers, not only Keywords, but also Form, Color and Texture, taking into account geometric transformations and variance like rotation, symmetry, mirroring, etc. Form - Edges extracted by an efficient segmentation algorithm. Color - Histogram, semantic color segmentation and spatial color relationship. Texture - Texture wavelets and local edge patterns. If required, Piria is also able to fuse results from multiple classifiers with a new classification of index categories: Single Indexer Single Call (SISC), Single Indexer Multiple Call (SIMC), Multiple Indexers Single Call (MISC) or Multiple Indexers Multiple Call (MIMC). Commercial and industrial applications will be explored and discussed as well as current and future development.

Focal mechanism and stress analyses for main tectonic zones in Albania

NASA Astrophysics Data System (ADS)

Dushi, Edmond; Koçi, Rexhep; Begu, Enkela; Bozo, Rrezart

2017-04-01

In this study, a number of 33 moderate earthquakes for the period 2013-2015, ranging in magnitude within 2.2 ≤ MW ≤ 4.9 and located within the Albanian territory, have been analyzed. As an earthquake prone country, situated at the frontal collision boundary between Adria microplate and Eurasian tectonic plate, Albania is characterized frequently by micro earthquakes, many moderate and seldom by strong ones. It is evidenced that the whole territory is divided in two different tectonic domains, correspondingly the outer and the inner domain, showing different stress regime as clearly evidenced based on earthquake focal mechanism and geodetic studies. Although strong earthquakes are clearly related to faults in tectonically active areas, moderate events are more frequent revealing valuable information on this purpose. All the studied events are selected to be well-recorded by a maximum possible number of the local broadband (BB) seismological stations of Albanian Seismological Network (ASN), although regional stations have been used as well to constrain the solution. Earthquakes are grouped according to their location, within three well-defined tectonic zones, namely: Adriatic-Ionian (AI), Lushnja-Elbasani-Dibra (LED) and Ohrid-Korça (OK). For each event, the seismic moment M0is determined, through spectral analyses. Moment values vary ranging 1012 - 1015 Nm, for the Adriatic-Ionian (AI) outer zone; 1013 - 1016 Nm, for the Lushnja-Elbasani-Dibra (LED) transversal zone, which cuts through both the outer and the inner domains and 1012 - 1014 Nm, for the Ohrid-Korça (OK), north-south trending inner zone. Focal mechanism solutions (FMS) have been determined for each earthquake, based on the robust first motion polarities method, as applied in the FOCMEC (Seisan 10.1) routine. Using the Michael's linear bootstrap invertion on FMS, a stress analysis is applied. Results show the minimum compressional stress directions variation: σ1 370/270, σ23030/80 and σ31980/620 (μ = 0.4) for AI zone; σ1830/90, σ22040/730and σ33500/140 (μ = 0.4) for LED zone and σ13060/430, σ21860/280 and σ3750/340 (μ = 0.65) for OK zone. Based on final results, according to Zoback (1992), the Adriatic-Ionian (AI) zone is characterized mainly by thrust (TF) faulting, although normal and oblique ones take place as well. This outer zone is under a compressive stress regime, where the maximum horizontal stress lies in the direction of P axes. Meanwhile, the Lushnja-Elbasani-Dibra (LED) transversal zone, is characterized by normal-oblique faulting (NF-NS), undergoing an oblique transform to extensional stress regime, where the maximum horizontal stress extends at the (T + 900) direction. The Ohrid-Korça (OK) zone is characterized by oblique-normal faults, undergoing and extensional stress regime, where the maximum horizontal stress lies in the of T axes direction. Keywords: moderate earthquakes, focal mechanism, stress

Investigation Of North Anatolian Fault In The Sea Of Marmara: Fault Geometry, The Cumulative Extension, Age Modeling In Çinarcik Basin Using Multi Channel Seismic Reflection Data

NASA Astrophysics Data System (ADS)

Atgın, Orhan; Çifçi, Günay; Soelien, Christopher; Seeber, Leonardo; Steckler, Michael; Shillington, Donna; Kurt, Hülya; Dondurur, Derman; Okay, Seda; Gürçay, Savaş; Sarıtaş, Hakan; Mert Küçük, H.; Barın, Burcu

2013-04-01

Marmara Sea is a limelight area for investigations due to its tectonic structure and remarkable seismic activity of North Anatolian Fault Zone (NAFZ). As NAFZ separates into 3 branches in the Marmara Sea, it has a complicated tectonic structure which gives rise to debates among researchers. Çınarcık Basin, which is close to Istanbul and very important for its tectonic activity is studied in this thesis. Two different multichannel seismic reflection data were used in this thesis. First data were acquired in 2008 in the frame of TAMAM (Turkish American Multichannel Project) and second data were in 2010 in the frame of TAMAM-2 (PirMarmara) onboard R/V K.Piri Reis. Also high resolution multibeam data were used which is provided by French Marine Institute IFREMER. In the scope of TAMAM project total 3000 km high resolution multi channel data were collected. 3000 km of multichannel seismic reflection profiles were collected in 2008 and 2010 using 72, 111, and 240 channels of streamer with a 6.25 m group interval. The generator-injector airgun was fired every 12.5 or 18.75 m and the resulting MCS data has 10-230 Hz frequency band. In this study, a detailed fault map of the basin is created and the fault on the southern slope of the basin which is interpreted by many researchers in many publications was investigated. And there is no evidence that such a fault exists on the southern part of the basin. With the multichannel seismic reflection data seismic stratigrafic interpretations of the basin deposits were done. The yearly cumulative north-south extension of the basin was calculated by making some calculations on the most active part of the faulting in the basin. In addition, the tilt angles of parallel tilted sediments were calculated and correlated with global sea level changes to calculate ages of the deposits in the basin. Keywords: NAFZ, multi channel seismic reflection, Çınarcık Basin

Anisotropy and tectonic deformation in the Ordos basin revealed by an active source seismic experiment

NASA Astrophysics Data System (ADS)

Jun, W. S.; Wang, F.; Xu, T.

2016-12-01

With the purpose of exploring the Ordos block, western North China Craton, two controlled-source deep seismic transects were conducted across this region. The first one is a 650 km long profile oriented N-S; the second is 1530 km and is oriented E-W. The upper mantle P wave-velocity derived from these profiles features a 0.25 km/s difference between them. Being the E-W higher that the N-S. The results obtained from both seismic profiles indicate that the upper mantle beneath the Ordos block presents seismic anisotropy in terms of discrepancy in Pn-wave velocity, such as the apparent seismic velocities observed along the two reference profiles demonstrate. This result is consistent with SKS-wave splitting measurements in the interior of the Ordos block. This indicates that the compressive stress state in Ordos during the Mesozoic became an extensional stress state in the Cenozoic. The high-velocity anomaly in the uppermost mantle under the west-east profile suggests that the lithospheric mantle is still not water-rich. Unlike what happened in the NCC to east of the Taihang Mountains, where the lithosphere experienced its thinning and destruction since the Mesozoic, the lithosphere in the interior of Ordos has suffered less deformation and remained tectonically stable. Keywords: wide-angle seismic profiling, Pn phase, high-velocity anomaly, upper mantle anisotropy, Ordos block, North China Craton. ReferencesChen L., 2009. Lithospheric structure variations between the eastern and central North China Craton from S- and P-receiver function migration. Phys. Earth Planet. Inter. 173, 216-227. Gao S., Rudnick R.L., Xu W.L., et al., 2008. Recycling deep cratonic lithosphere and generation of intraplate magmatism in the North China Craton. Earth Planet. Sci. Lett. 270, 41-53. Xu T., Zhang Z.J., Gao E.G., et al., 2010. Segmentally iterative ray tracing in complex 2D and 3D heterogeneous block models. Bull. Seism. Soc. Am. 100, 841-850. Zhu R.X., Zheng T.Y., 2009. Destruction geodynamics of the North China Craton and its Paleoproterozoic plate tectonics. Chinese Sci. Bull. 54(14), 1950-1961 (in Chinese).

Where the bugs are: analyzing distributions of bacterial phyla by descriptor keyword search in the nucleotide database.

PubMed

Squartini, Andrea

2011-07-26

The associations between bacteria and environment underlie their preferential interactions with given physical or chemical conditions. Microbial ecology aims at extracting conserved patterns of occurrence of bacterial taxa in relation to defined habitats and contexts. In the present report the NCBI nucleotide sequence database is used as dataset to extract information relative to the distribution of each of the 24 phyla of the bacteria superkingdom and of the Archaea. Over two and a half million records are filtered in their cross-association with each of 48 sets of keywords, defined to cover natural or artificial habitats, interactions with plant, animal or human hosts, and physical-chemical conditions. The results are processed showing: (a) how the different descriptors enrich or deplete the proportions at which the phyla occur in the total database; (b) in which order of abundance do the different keywords score for each phylum (preferred habitats or conditions), and to which extent are phyla clustered to few descriptors (specific) or spread across many (cosmopolitan); (c) which keywords individuate the communities ranking highest for diversity and evenness. A number of cues emerge from the results, contributing to sharpen the picture on the functional systematic diversity of prokaryotes. Suggestions are given for a future automated service dedicated to refining and updating such kind of analyses via public bioinformatic engines.

Detecting spam comments on Indonesia’s Instagram posts

NASA Astrophysics Data System (ADS)

Septiandri, Ali Akbar; Wibisono, Okiriza

2017-01-01

In this paper we experimented with several feature sets for detecting spam comments in social media contents authored by Indonesian public figures. We define spam comments as comments which have promotional purposes (e.g. referring other users to products and services) and thus not related to the content to which the comments are posted. Three sets of features are evaluated for detecting spams: (1) hand-engineered features such as comment length, number of capital letters, and number of emojis, (2) keyword features such as whether the comment contains advertising words or product-related words, and (3) text features, namely, bag-of-words, TF-IDF, and fastText embeddings, each combined with latent semantic analysis. With 24,000 manually-annotated comments scraped from Instagram posts authored by more than 100 Indonesian public figures, we compared the performance of these feature sets and their combinations using 3 popular classification algorithms: Na¨ıve Bayes, SVM, and XGBoost. We find that using all three feature sets (with fastText embedding for the text features) gave the best F 1-score of 0.9601 on a holdout dataset. More interestingly, fastText embedding combined with hand-engineered features (i.e. without keyword features) yield similar F 1-score of 0.9523, and McNemar’s test failed to reject the hypothesis that the two results are not significantly different. This result is important as keyword features are largely dependent on the dataset and may not be as generalisable as the other feature sets when applied to new data. For future work, we hope to collect bigger and more diverse dataset of Indonesian spam comments, improve our model’s performance and generalisability, and publish a programming package for others to reliably detect spam comments.

Basin deconstruction-construction: Seeking thermal-tectonic consistency through the integration of geochemical thermal indicators and seismic fault mechanical stratigraphy ​- Example from Faras Field, North Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Pigott, John D.; Abouelresh, Mohamed O.

2016-02-01

To construct a model of a sedimentary basin's thermal tectonic history is first to deconstruct it: taking apart its geological elements, searching for its initial conditions, and then to reassemble the elements in the temporal order that the basin is assumed to have evolved. Two inherent difficulties implicit to the analysis are that most organic thermal indicators are cumulative, irreversible and a function of both temperature and time and the non-uniqueness of crustal strain histories which complicates tectonic interpretations. If the initial conditions (e.g. starting maturity of the reactants and initial crustal temperature) can be specified and the boundary conditions incrementally designated from changes in the lithospheric heat engine owing to stratigraphic structural constraints, then the number of pathways for the temporal evolution of a basin is greatly reduced. For this investigation, model input uncertainties are reduced through seeking a solution that iteratively integrates the geologically constrained tectonic subsidence, geochemically constrained thermal indicators, and geophysically constrained fault mechanical stratigraphy. The Faras oilfield in the Abu Gharadig Basin, North Western Desert, Egypt, provides an investigative example of such a basin's deconstructive procedure. Multiple episodes of crustal extension and shortening are apparent in the tectonic subsidence analyses which are constrained from the fault mechanical stratigraphy interpreted from reflection seismic profiles. The model was iterated with different thermal boundary conditions until outputs best fit the geochemical observations. In so doing, the thermal iterations demonstrate that general relationship that basin heat flow increases decrease vertical model maturity gradients, increases in surface temperatures shift vertical maturity gradients linearly to higher values, increases in sediment conductivities lower vertical maturities with depth, and the addition of ;ghost; layers (those layers removed) prior to the erosional event increase maturities beneath, and conversely. These integrated constraints upon the basin evolution model indicate that the principal source rocks, Khatatba and the lowest part of the Alam El Bueib formations, entered the oil window at approximately 95 Ma and the gas window at approximately 25 Ma. The upper part of the Alam El Bueib Formation is within the oil window at the present day. Establishing initial and boundary value conditions for a basin's thermal evolution when geovalidated by the integration of seismic fault mechanical stratigraphy, tectonic subsidence analysis, and organic geochemical maturity indicators provides a powerful tool for optimizing petroleum exploration in both mature and frontier basins.

Filtering Access to Internet Content at Higher Education Institutions: Stakeholder Perceptions and Their Impact on Research and Academic Freedom

ERIC Educational Resources Information Center

Orenstein, David I.

2009-01-01

Hardware and software filters, which sift through keywords placed in Internet search engines and online databases, work to limit the return of information from these sources. By their very purpose, filters exist to decrease the amount of information researchers can access. The purpose of this study is to gain insight into the perceptions key…

Multiple Factors-Aware Diffusion in Social Networks

DTIC Science & Technology

2015-05-22

Multiple Factors-Aware Diffusion in Social Networks Chung-Kuang Chou(B) and Ming-Syan Chen Department of Electrical Engineering, National Taiwan...propagates from nodes to nodes over a social network . The behavior that a node adopts an information piece in a social network can be affected by...Twitter dataset. Keywords: Social networks · Diffusion models 1 Introduction Information diffusion in social networks has been an active research field

Assisting Design Given Multiple Performance Criteria

DTIC Science & Technology

1988-08-01

with uninstantiated operators is created then each operator’s implementation is selected. g - Keywords: computer-aided design, artificial...IEEE Trans- actions on Software Engineering, SE-7(1), 1981. [BG86] Forrest D. Brewer and Daniel D. Gajski . An expert-system paradigm for de- sign. In...Teukolsky, api William T. Vet- terling. Numerical Recipes. Cambridge University Press, Cambridge, England, 1987. [RFS83] G . G . Rassweiler, M. D

Quantifying the heterogeneity of the tectonic stress field using borehole data

USGS Publications Warehouse

Schoenball, Martin; Davatzes, Nicholas C.

2017-01-01

The heterogeneity of the tectonic stress field is a fundamental property which influences earthquake dynamics and subsurface engineering. Self-similar scaling of stress heterogeneities is frequently assumed to explain characteristics of earthquakes such as the magnitude-frequency relation. However, observational evidence for such scaling of the stress field heterogeneity is scarce.We analyze the local stress orientations using image logs of two closely spaced boreholes in the Coso Geothermal Field with sub-vertical and deviated trajectories, respectively, each spanning about 2 km in depth. Both the mean and the standard deviation of stress orientation indicators (borehole breakouts, drilling-induced fractures and petal-centerline fractures) determined from each borehole agree to the limit of the resolution of our method although measurements at specific depths may not. We find that the standard deviation in these boreholes strongly depends on the interval length analyzed, generally increasing up to a wellbore log length of about 600 m and constant for longer intervals. We find the same behavior in global data from the World Stress Map. This suggests that the standard deviation of stress indicators characterizes the heterogeneity of the tectonic stress field rather than the quality of the stress measurement. A large standard deviation of a stress measurement might be an expression of strong crustal heterogeneity rather than of an unreliable stress determination. Robust characterization of stress heterogeneity requires logs that sample stress indicators along a representative sample volume of at least 1 km.

Incorporation of New and Old Tectonics Concepts Into a Modern Course in Tectonics.

ERIC Educational Resources Information Center

Hatcher, Robert D., Jr.

1983-01-01

Describes a graduate-level tectonics course which includes the historical basis for modern tectonics concepts and an in-depth review of pros/cons of plate tectonics. Tectonic features discussed include: ocean basins; volcanic arcs; continental margins; continents; orogenic belts; foreland fold and thrust belts; volcanic/plutonic belts of orogens;…

GPS Constraints on the Spatial Distribution of Extension in the Ethiopian Highlands and Main Ethiopian Rift

NASA Astrophysics Data System (ADS)

Amere, Y. B.; Bendick, R. O.; Fisseha, S.; Lewi, E.; Reilinger, R. E.; King, R. W.; Kianji, G.

2014-12-01

27 campaign and 17 continuous GPS sites spanning the Ethiopian Highlands, Main Ethiopian Rift (MER), and Somali Platform in Ethiopia and Eritrea were measured for varying durations between 1995 and 2014. Velocities at these sites show that present day strain in NE Africa is not localized only in the Afar depression and MER system. Rather, velocities as high as 6 mm/yr relative to stable Nubia occur in the central Ethiopian highlands west of the rift bounding faults; the northern and southern Ethiopian highlands host velocities as high as 3 mm/yr. These approach the magnitude of Nubia-Somalia spreading accommodated within the rift itself of 6 + 1 mm/yr with an azimuth of N770E. The combination of distributed low strain rate deformation contiguous with higher strain rate plate boundary deformation is similar to that expressed in other tectonically active continental settings like Basin and Range and Tibetan Plateau.Keywords: deformation, localized, distributed, strain, stable Nubia.

A review of instrumentation kinematics of engine-driven nickel-titanium instruments.

PubMed

Çapar, I D; Arslan, H

2016-02-01

Over the years, NiTi alloys have become indispensable materials in endodontic treatment. With technological advancements in metallurgy, manufacturers have attempted to produce instruments with enhanced features. In parallel with these developments, endodontic motors have undergone improvements in terms of torque control and kinematics that are adjustable in different directions. This review presents an overview of the advancements in instrumentation kinematics and the effect of instrumentation kinematics on root canal shaping procedures and instrument performance. The literature search for this narrative review was conducted in Google Scholar, Scopus, PubMed and Web of Science using the keywords 'kinematics and endodontics' and 'reciprocation and endodontics'. In addition, historical literature was searched using the keyword 'nickel-titanium and endodontics'. Overall, 143 articles were included up to 2015. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

Regional Tectonic Control of Tertiary Mineralization and Recent Faulting in the Southern Basin-Range Province, an Application of ERTS-1 Data

NASA Technical Reports Server (NTRS)

Bechtold, I. C.; Liggett, M. A.; Childs, J. F.

1973-01-01

Research based on ERTS-1 MSS imagery and field work in the southern Basin-Range Province of California, Nevada and Arizona has shown regional tectonic control of volcanism, plutonism, mineralization and faulting. This paper covers an area centered on the Colorado River between 34 15' N and 36 45' N. During the mid-Tertiary, the area was the site of plutonism and genetically related volcanism fed by fissure systems now exposed as dike swarms. Dikes, elongate plutons, and coeval normal faults trend generally northward and are believed to have resulted from east-west crustal extension. In the extensional province, gold silver mineralization is closely related to Tertiary igneous activity. Similarities in ore, structural setting, and rock types define a metallogenic district of high potential for exploration. The ERTS imagery also provides a basis for regional inventory of small faults which cut alluvium. This capability for efficient regional surveys of Recent faulting should be considered in land use planning, geologic hazards study, civil engineering and hydrology.

Relations between some horizontal‐component ground‐motion intensity measures used in practice

USGS Publications Warehouse

Boore, David; Kishida, Tadahiro

2017-01-01

Various measures using the two horizontal components of recorded ground motions have been used in a number of studies that derive ground‐motion prediction equations and construct maps of shaking intensity. We update relations between a number of these measures, including those in Boore et al. (2006) and Boore (2010), using the large and carefully constructed global database of ground motions from crustal earthquakes in active tectonic regions developed as part of the Pacific Earthquake Engineering Research Center–Next Generation Attenuation‐West2 project. The ratios from the expanded datasets generally agree to within a few percent of the previously published ratios. We also provide some ratios that were not considered before, some of which will be useful in applications such as constructing ShakeMaps. Finally, we compare two important ratios with those from a large central and eastern North American database and from many records from subduction earthquakes in Japan and Taiwan. In general, the ratios from these regions are within several percent of those from crustal earthquakes in active tectonic regions.

Living on an Active Earth: Perspectives on Earthquake Science

NASA Astrophysics Data System (ADS)

Lay, Thorne

2004-02-01

The annualized long-term loss due to earthquakes in the United States is now estimated at $4.4 billion per year. A repeat of the 1923 Kanto earthquake, near Tokyo, could cause direct losses of $2-3 trillion. With such grim numbers, which are guaranteed to make you take its work seriously, the NRC Committee on the Science of Earthquakes begins its overview of the emerging multidisciplinary field of earthquake science. An up-to-date and forward-looking survey of scientific investigation of earthquake phenomena and engineering response to associated hazards is presented at a suitable level for a general educated audience. Perspectives from the fields of seismology, geodesy, neo-tectonics, paleo-seismology, rock mechanics, earthquake engineering, and computer modeling of complex dynamic systems are integrated into a balanced definition of earthquake science that has never before been adequately articulated.

2001 Bhuj, India, earthquake engineering seismoscope recordings and Eastern North America ground-motion attenuation relations

USGS Publications Warehouse

Cramer, C.H.; Kumar, A.

2003-01-01

Engineering seismoscope data collected at distances less than 300 km for the M 7.7 Bhuj, India, mainshock are compatible with ground-motion attenuation in eastern North America (ENA). The mainshock ground-motion data have been corrected to a common geological site condition using the factors of Joyner and Boore (2000) and a classification scheme of Quaternary or Tertiary sediments or rock. We then compare these data to ENA ground-motion attenuation relations. Despite uncertainties in recording method, geological site corrections, common tectonic setting, and the amount of regional seismic attenuation, the corrected Bhuj dataset agrees with the collective predictions by ENA ground-motion attenuation relations within a factor of 2. This level of agreement is within the dataset uncertainties and the normal variance for recorded earthquake ground motions.

Proceedings of Conference XIII, evaluation of regional seismic hazards and risk

USGS Publications Warehouse

Charonnat, Barbara B.

1981-01-01

The participants in the conference concluded that a great deal of useful research has been performed in the national Earthquake Hazards Reduction Program by USGS and non-USGS scientists and engineers and that the state-of-knowledge concerning the evaluation of seismic hazards and risk has been advanced substantially. Many of the technical issues raised during the conference are less controversial now because of new information and insights gained during the first three years of the expanded research program conducted under the Earthquake Hazards Reduction Act. Utilization of research results by many groups of users has also improved during this period and further improvement in utilization appears likely. Additional research is still required to resolve more completely the many complex technical issues summarized above and described in the papers contained in the proceedings. Improved certainty of research results on the evaluation of regional seismic hazards and risk is required before full utilization can be made by state and local governments who deal. with people frequently having a different perception of the hazard and its risk to them than that perceived by scientists or engineers. Each of the papers contained in the proceedings contain throughtful recommendations for improving the state-of-knowledge. Two papers, in particular, focussed on this particular theme. The first was presented by Lynn Sykes in the Geologic Keynote Address. He identified geographic areas throughout the world which may be considered as counterparts or analogues of seismic zones in the United States. He concluded that much can be learned about prediction, tectonic settings, earthquake hazards, and earthquake risk for sites in the United States by studying their tectonic analogues in other countries. The second paper was presented by John Blume in the Engineering Keynote Address. He suggested 20 specific research topics that, in his opinion, will significantly advance the state-of-the-art in earthquakeresistant design. The papers by Sykes and Blume are presented in the front of the proceedings.

Numerical investigation of the triggering mechanisms of the Piz Dora sackung system (Val Mustair, Switzerland)

NASA Astrophysics Data System (ADS)

Riva, Federico; Agliardi, Federico; Crosta, Giovanni B.; Zanchi, Andrea

2015-04-01

Deep-Seated Gravitational Slope Deformations (DSGSD) are widespread phenomena in alpine environments, where they affect entire high-relief valley flanks involving huge rock volumes. Slope scale inherited structures related to ductile and brittle tectonic deformation can control the onset and development of DSGSD and the localization of strain in deep gravitational shear zones. Slope unloading, rock mass damage and hydrological perturbations related to deglaciation are considered important triggers of these phenomena in formerly glaciated areas. Furthermore, earthquake shaking and the long-term effects of seismicity in active tectonic areas might provide an additional triggering component. Nevertheless, the role played by these different processes and their interplay is not obvious, especially in geological context less typically favourable to DSGSD and in low-magnitude seismicity settings as the axial European Alps. We analysed the Piz Dora sackung system (Val Mustair, Switzerland), which affects conglomerates, meta-conglomerates and phyllites of the Austroalpine S-Charl nappe, involved in a slope-scale, WNW trending closed anticline fold. The area is actively uplifting, seismically active (maximum Mw>5) and experienced extensive glaciation during the LGM. The slope is affected by sharp gravitational morphostructures associated to the deep-seated sliding of 1.85 km3 of rock along a basal shear zone up to 300 m deep (Agliardi et al., 2014; Barbarano et al., 2015). We investigated the controlling role of inherited tectonic features and the relative influence of different candidate triggering processes (post-glacial debuttressing, related changes in slope hydrology, seismicity) through a series of 2D Distinct Element (DEM) numerical models set up using the code UDEC (ItascaTM). Based on field structural and geomechanical data, we discretized the slope into an ensemble of discontinuum domains, accounting for the slope-scale folded structure and characterised by unique combinations of rock mass properties and persistent brittle structural patterns related to folding or regional stress fields. We analysed the processes leading to DSGSD onset and evolution by testing combinations of: a) rock mass constitutive models; b) in situ stress fields; c) hydro-mechanical coupling; d) dynamic loadings. DEM results, validated using field evidence and discussed against the results of continuum-based Finite-Element models (Agliardi et al., 2014; Barbarano et al., 2015), suggest that DSGSD failure mechanisms are constrained by fold-related brittle structures, and stress and hydrologic conditioning of deglaciation were key triggers modulated by active tectonic processes. References: - Agliardi F., Barbarano M., Crosta G.B., Riva F. & Zanchi A. (2014). Inherited and active tectonic controls on the Piz Dora sackung system (Val Mustair). In 3rd Slope Tectonic Conference proceedings, NGU Report 2014.030. - Barbarano M., Agliardi F., Crosta G. B., & Zanchi A. (2015). Inherited and Active Tectonic Controls on the Piz Dora DSGSD (Val Müstair, Switzerland). In Engineering Geology for Society and Territory-Volume 2 (pp. 605-608). Springer International Publishing.

Opportunities for Web-Based Indicators in Environmental Sciences

PubMed Central

Malcevschi, Sergio; Marchini, Agnese; Savini, Dario; Facchinetti, Tullio

2012-01-01

This paper proposes a set of web-based indicators for quantifying and ranking the relevance of terms related to key-issues in Ecology and Sustainability Science. Search engines that operate in different contexts (e.g. global, social, scientific) are considered as web information carriers (WICs) and are able to analyse; (i) relevance on different levels: global web, individual/personal sphere, on-line news, and culture/science; (ii) time trends of relevance; (iii) relevance of keywords for environmental governance. For the purposes of this study, several indicators and specific indices (relational indices and dynamic indices) were applied to a test-set of 24 keywords. Outputs consistently show that traditional study topics in environmental sciences such as water and air have remained the most quantitatively relevant keywords, while interest in systemic issues (i.e. ecosystem and landscape) has grown over the last 20 years. Nowadays, the relevance of new concepts such as resilience and ecosystem services is increasing, but the actual ability of these concepts to influence environmental governance needs to be further studied and understood. The proposed approach, which is based on intuitive and easily replicable procedures, can support the decision-making processes related to environmental governance. PMID:22905118

Opportunities for web-based indicators in environmental sciences.

PubMed

Malcevschi, Sergio; Marchini, Agnese; Savini, Dario; Facchinetti, Tullio

2012-01-01

This paper proposes a set of web-based indicators for quantifying and ranking the relevance of terms related to key-issues in Ecology and Sustainability Science. Search engines that operate in different contexts (e.g. global, social, scientific) are considered as web information carriers (WICs) and are able to analyse; (i) relevance on different levels: global web, individual/personal sphere, on-line news, and culture/science; (ii) time trends of relevance; (iii) relevance of keywords for environmental governance. For the purposes of this study, several indicators and specific indices (relational indices and dynamic indices) were applied to a test-set of 24 keywords. Outputs consistently show that traditional study topics in environmental sciences such as water and air have remained the most quantitatively relevant keywords, while interest in systemic issues (i.e. ecosystem and landscape) has grown over the last 20 years. Nowadays, the relevance of new concepts such as resilience and ecosystem services is increasing, but the actual ability of these concepts to influence environmental governance needs to be further studied and understood. The proposed approach, which is based on intuitive and easily replicable procedures, can support the decision-making processes related to environmental governance.

SAFER Under Vehicle Inspection Through Video Mosaic Building

DTIC Science & Technology

2004-01-01

this work were taken using a Polaris Wp-300c Lipstick video camera mounted on a mobile platform. Infrared video was taken using a Raytheon PalmIR PRO...Tank- Automotive Research, Development and Engineering Center, US Army RDECOM, Warren, Michigan, USA. Keywords Inspection, Road vehicles, State...security, Robotics Abstract The current threats to US security, both military and civilian, have led to an increased interest in the development of

Balkanized research in ecological engineering revealed by a bibliometric analysis of earthworms and ecosystem services.

PubMed

Blouin, Manuel; Sery, Nicolas; Cluzeau, Daniel; Brun, Jean-Jacques; Bédécarrats, Alain

2013-08-01

Energy crisis, climate changes, and biodiversity losses have reinforced the drive for more ecologically-based approaches for environmental management. Such approaches are characterized by the use of organisms rather than energy-consuming technologies. Although earthworms are believed to be potentially useful organisms for managing ecosystem services, there is actually no quantification of such a trend in literature. This bibliometric analysis aimed to measure the evolution of the association of "earthworms" and other terms such as ecosystem services (primary production, nutrient cycling, carbon sequestration, soil structure, and pollution remediation), "ecological engineering" or "biodiversity," to assess their convergence or divergence through time. In this aim, we calculated the similarity index, an indicator of the paradigmatic proximity defined in applied epistemology, for each year between 1900 and 2009. We documented the scientific fields and the geographical origins of the studies, as well as the land uses, and compare these characteristics with a 25 years old review on earthworm management. The association of earthworm related keywords with ecosystem services related keywords was increasing with time, reflecting the growing interest in earthworm use in biodiversity and ecosystem services management. Conversely, no significant increase in the association between earthworms and disciplines such as ecological engineering or restoration ecology was observed. This demonstrated that general ecologically-based approaches have yet to emerge and that there is little exchange of knowledge, methods or concepts among balkanized application realms. Nevertheless, there is a strong need for crossing the frontiers between fields of application and for developing an umbrella discipline to provide a framework for the use of organisms to manage ecosystem services.

Development of a Google-based search engine for data mining radiology reports.

PubMed

Erinjeri, Joseph P; Picus, Daniel; Prior, Fred W; Rubin, David A; Koppel, Paul

2009-08-01

The aim of this study is to develop a secure, Google-based data-mining tool for radiology reports using free and open source technologies and to explore its use within an academic radiology department. A Health Insurance Portability and Accountability Act (HIPAA)-compliant data repository, search engine and user interface were created to facilitate treatment, operations, and reviews preparatory to research. The Institutional Review Board waived review of the project, and informed consent was not required. Comprising 7.9 GB of disk space, 2.9 million text reports were downloaded from our radiology information system to a fileserver. Extensible markup language (XML) representations of the reports were indexed using Google Desktop Enterprise search engine software. A hypertext markup language (HTML) form allowed users to submit queries to Google Desktop, and Google's XML response was interpreted by a practical extraction and report language (PERL) script, presenting ranked results in a web browser window. The query, reason for search, results, and documents visited were logged to maintain HIPAA compliance. Indexing averaged approximately 25,000 reports per hour. Keyword search of a common term like "pneumothorax" yielded the first ten most relevant results of 705,550 total results in 1.36 s. Keyword search of a rare term like "hemangioendothelioma" yielded the first ten most relevant results of 167 total results in 0.23 s; retrieval of all 167 results took 0.26 s. Data mining tools for radiology reports will improve the productivity of academic radiologists in clinical, educational, research, and administrative tasks. By leveraging existing knowledge of Google's interface, radiologists can quickly perform useful searches.

Earthquake Hazard and the Environmental Seismic Intensity (ESI) Scale

NASA Astrophysics Data System (ADS)

Serva, Leonello; Vittori, Eutizio; Comerci, Valerio; Esposito, Eliana; Guerrieri, Luca; Michetti, Alessandro Maria; Mohammadioun, Bagher; Mohammadioun, Georgianna C.; Porfido, Sabina; Tatevossian, Ruben E.

2016-05-01

The main objective of this paper was to introduce the Environmental Seismic Intensity scale (ESI), a new scale developed and tested by an interdisciplinary group of scientists (geologists, geophysicists and seismologists) in the frame of the International Union for Quaternary Research (INQUA) activities, to the widest community of earth scientists and engineers dealing with seismic hazard assessment. This scale defines earthquake intensity by taking into consideration the occurrence, size and areal distribution of earthquake environmental effects (EEE), including surface faulting, tectonic uplift and subsidence, landslides, rock falls, liquefaction, ground collapse and tsunami waves. Indeed, EEEs can significantly improve the evaluation of seismic intensity, which still remains a critical parameter for a realistic seismic hazard assessment, allowing to compare historical and modern earthquakes. Moreover, as shown by recent moderate to large earthquakes, geological effects often cause severe damage"; therefore, their consideration in the earthquake risk scenario is crucial for all stakeholders, especially urban planners, geotechnical and structural engineers, hazard analysts, civil protection agencies and insurance companies. The paper describes background and construction principles of the scale and presents some case studies in different continents and tectonic settings to illustrate its relevant benefits. ESI is normally used together with traditional intensity scales, which, unfortunately, tend to saturate in the highest degrees. In this case and in unpopulated areas, ESI offers a unique way for assessing a reliable earthquake intensity. Finally, yet importantly, the ESI scale also provides a very convenient guideline for the survey of EEEs in earthquake-stricken areas, ensuring they are catalogued in a complete and homogeneous manner.

Relocation of earthquakes at southwestern Indian Ocean Ridge and its tectonic significance

NASA Astrophysics Data System (ADS)

Luo, W.; Zhao, M.; Haridhi, H.; Lee, C. S.; Qiu, X.; Zhang, J.

2015-12-01

The southwest Indian Ridge (SWIR) is a typical ultra-slow spreading ridge (Dick et al., 2003) and further plate boundary where the earthquakes often occurred. Due to the lack of the seismic stations in SWIR, positioning of earthquakes and micro-earthquakes is not accurate. The Ocean Bottom Seismometers (OBS) seismic experiment was carried out for the first time in the SWIR 49 ° 39 'E from Jan. to March, 2010 (Zhao et al., 2013). These deployed OBS also recorded the earthquakes' waveforms during the experiment. Two earthquakes occurred respectively in Feb. 7 and Feb. 9, 2010 with the same magnitude of 4.4 mb. These two earthquakes were relocated using the software HYPOSAT based on the spectrum analysis and band-pass (3-5 Hz) filtering and picking up the travel-times of Pn and Sn. Results of hypocentral determinations show that there location error is decreased significantly by joined OBS's recording data. This study do not only provide the experiences for the next step deploying long-term wide-band OBSs, but also deepen understanding of the structure of SWIR and clarify the nature of plate tectonic motivation. This research was granted by the Natural Science Foundation of China (41176053, 91028002, 91428204). Keywords: southwest Indian Ridge (SWIR), relocation of earthquakes, Ocean Bottom Seismometers (OBS), HYPOSAT References:[1] Dick, H. J. B., Lin J., Schouten H. 2003. An ultraslow-spreading class of ocean ridge. Nature, 426(6965): 405-412. [2] Zhao M. H., et al. 2013. Three-dimensional seismic structure of the Dragon Flag oceanic core complex at the ultraslow spreading Southwest Indian Ridge (49°39' E). Geochemistry Geophysics Geosystems, 14(10): 4544-4563.

Tectono-thermal History of the Southern Nenana Basin, Interior Alaska: Implications for Conventional and Unconventional Hydrocarbon Exploration

NASA Astrophysics Data System (ADS)

Dixit, N. C.; Hanks, C. L.

2014-12-01

The Tertiary Nenana basin of Interior Alaska is currently the focus of both new oil exploration and coalbed methane exploitation and is being evaluated as a potential CO2sequestration site. The basin first formed as a Late Paleocene extensional rift with the deposition of oil and gas-prone, coal-bearing non-marine sediments with excellent source potential. Basin inversion during the Early Eocene-Early Oligocene times resulted in folding and erosion of higher stratigraphic levels, forming excellent structural and stratigraphic traps. Initiation of active faulting on its eastern margin in the middle Oligocene caused slow tectonic subsidence that resulted in the deposition of reservoir and seal rocks of the Usibelli Group. Onset of rapid tectonic subsidence in Pliocene that continues to the present-day has provided significant pressure and temperature gradient for the source rocks. Apatite fission-track and vitrinite reflectance data reveals two major paleo-thermal episodes: Late Paleocene to Early Eocene (60 Ma to 54.8 Ma) and Late Miocene to present-day (7 Ma to present). These episodes of maximum paleotemperatures have implications for the evolution of source rock maturity within the basin. In this study, we are also investigating the potential for coalbed methane production from the Late Paleocene coals via injection of CO2. Our preliminary analyses demonstrate that 150 MMSCF of methane could be produced while 33000 tonnes of CO2 per injection well (base case of ~9 years) can be sequestered in the vicinity of existing infrastructure. However, these volumes of sequestered CO2and coal bed methane recovery are estimates and are sensitive to the reservoir's geomechanical and flow properties. Keywords: extensional rift, seismic, subsidence, thermal history, fission track, vitrinite reflectance, coal bed methane, Nenana basin, CO2 sequestration

Scientific results of the NASA-sponsored study project on Mars: Evolution of volcanism, tectonics, and volatiles

NASA Technical Reports Server (NTRS)

Solomon, Sean C. (Editor); Sharpton, Virgil L. (Editor); Zimbelman, James R. (Editor)

1990-01-01

The objectives of the Mars: Evolution of Volcanism, Tectonics, and Volatiles (MEVTV) project are to outline the volcanic and tectonic history of Mars; to determine the influence of volatiles on Martian volcanic and tectonic processes; and to attempt to determine the compositional, thermal, and volatile history of Mars from its volcanic and tectonic evolution. Available data sets were used to test general models of the volcanic and tectonic history of Mars.

Tectonic, human and climate signal over the last 4000 years in the Lake Amik record (southern Turkey)

NASA Astrophysics Data System (ADS)

El Ouahabi, Meriam; Hubert-Ferrari, Aurélia; Vander Auwera, Jacqueline; Lepoint, Gilles; Karabacak, Volkan; Schmidt, Sabine; Fagel, Nathalie

2017-04-01

This study investigates the upper sediments infilling the central part of the Amik Basin in Southern Turkey. The Amik Basin is located in a tectonically active area: it is crossed by the Dead Sea Fault, a major neotectonic structure in the Middle East extending from the Red Sea in the South to the East Anatolian Fault Zone in the North. Continuous human occupation is attested since 6000-7000 BC in the Amik Basin. The study focuses on the sedimentary record of the Lake Amik occupying the central part of the Basin. Our objective is to constrain major paleo-environmental changes over the last 4000 years. The lake has been drained and progressively dried up since the mid-50s. The absence of water column during the summer season allows to collect lacustrine samples along a 5 meter depth trench with a sampling resolution of 1 to 2 cm. Diverse complementary methods were applied to characterize the sedimentary record: i.e. magnetic susceptibility, grain size, organic and inorganic matter by loss-of-ignition, mineralogy by X-ray diffraction and core scanner X-ray fluorescence (XRF) geochemistry. The age of the record is constrained combining radionuclide and radiocarbon datings. Structural disturbances observed in the lacustrine sediments record are linked with major historical earthquakes from the 6th to the 9th century AD due to the Hasipasa Fault rupture. In addition to the tectonic influence, the sedimentary record clearly shows two periods indicating strong soil erosion in the lake catchment: (1) the most recent erosion phase occurs over the Roman period to Present; (2) the oldest one would have occurred during the Late Bronze period. Such changes are most probably related to change in land use. In term of climate influences, the mineralogical and geochemical results allow to evidence variations in chemical weathering conditions in the watershed and lake water level fluctuations, respectively. The clay mineral assemblages attest for significant pedogenesis transformations, especially during the Islamic/Ottoman period. Based on XRF results, an increase in potassium is attributed to a lake development phase during a wet phase An overflow of the Orontes River would be responsible for clay deposition. By contrast, increased calcium and strontium rather correspond to a low lacustrine level and a drier period. The Bronze and Iron/Hellenistic periods are both characterized by low lake level with limited contribution from the watershed. To conclude, our multiproxy study of the Lake Amik allows to decipher between tectonic, human and climate influences over the last 4000 years. Further step would be to compare the Amik record with other regional archives to evidence local and regional events. Keywords: Climate; Weathering conditions; Land erosion; Clay mineralogy; Lake sediments; Last millenia.

Engineered Herpes Simplex Viruses for the Treatment of Malignant Peripheral Nerve Sheath Tumors

DTIC Science & Technology

2014-09-01

patients with neurofibromatosis type I (NF-1) will develop benign neurofibromas in their peripheral nerves that will progress to malignant tumors that...lines to activate anti-viral signaling pathways. Keywords: MPNST, neurofibromatosis , oncolytic virus, HSV-1, IL-12 In the first year of research, we...lysis and immune recruitment. As rare and aggressive tumors of glial origin, MPNSTs frequently arise from patients with type-1 neurofibromatosis , but

Repeated Exposure to Neurotoxic Levels of Chlorpyriphos Alters Hippocampal Expression of Neurotrophins and Neuropeptides

DTIC Science & Technology

2016-01-13

Institute for Science and Engineering, Oak Ridge, TN 37831, United States bUnited States Army Center for Environmental Health Research (USACEHR...online 13 January 2016 Keywords: Chlorpyrifos Cholinesterase inhibition Gene expression Microarray miRNA Organophosphorus pesticide A B S T R A C T...Chlorpyrifos (CPF), an organophosphorus pesticide (OP), is one of the most widely used pesticides in the world. Subchronic exposures to CPF that do not

Tracing medical information over the Internet.

PubMed

Mutairi, S M

2000-05-01

The Internet became with do doubt a huge and valuable source of information for researchers. The wealth of information on the Internet is second to none and medical information is no exception. Yet with the vast expansion of the Internet and the World Wide Web in specie, to find the kind of information one is looking for, he/she needs to browse thousands of web sites and the experience would be like digging into a stack of hay looking for a needle. That's why search engines and subject indexes, as means to overcome this problem, were introduced and grew so rapidly. In general, there are three approaches to retrieve data from the World Wide Web; the subject directories, search engines and detailed subject indexes. However, there is no single comprehensive search engine or directory and it is recommended to use more than one with different keywords and synonymous.

Multi-Disciplinary Type Creativity Education for Students from 15 years old to Bachelor Level in College of Technology

NASA Astrophysics Data System (ADS)

Yotsuyanagi, Takao; Ikeda, Senri; Suzuki, Katsuhiko; Kobayashi, Hiroshi; Sakuraba, Hiroshi; Shoji, Akira; Itoh, Masahiko

Creativity is the most fundamental keyword for engineers to solve the various problems in manufacturing products. This engineering “learning” cannot be achieved without the real experiences, especially by the teens who have the curiosity to know everything. New educational program has been innovated in Miyagi National College of Technology. This new curriculum started as “03C” in 2003. It involves two laboratories for mixed-departments type grouping, which intend to cultivate the creative ability for the 2nd year students in College Course and the 1st year students in Advanced Course as Engineering Design. This paper presents the trial of the new educational program on the cultivating creative ability designed for teen-agers, and discusses the processes in detail, results and further problems. This program will progress still more with continuous improvement of manufacturing subjects in cooperative with educational-industrial complex.

Unraveling Appalachian tectonics: domain analysis of topographic lineaments in Pennsylvania

NASA Astrophysics Data System (ADS)

Karimi, B.; Schon, K.; Nussbaum, G. W.; Storer, N. D.; McGuire, J. L.; Hardcastle, K.

2016-12-01

Litho-tectonic provinces provide different components of a regions' tectonic history, and are identified as spatial entities with common structural elements, or a number of contiguous related elements. The province boundaries are easily identified when geomorphic expressions are distinct, or significant rock exposure allows for little uncertainty. When exposures are limited, locations of boundaries between provinces are uncertain. In such instances, satellite imagery can be quite advantageous, as tectonically sourced features (faults, folds, fractures, and joints) may exert a strong control on topographic patterns by creating pathways for weathering and erosion. Lineament analyses of topography often focus on well-pronounced tectonic features to interpret regional tectonics. We suggest that lineament analyses including all topographic features may include more subtle tectonic features, resulting in the identification of minor heterogeneities within litho-tectonic provinces. Our study focuses on Appalachian tectonics, specifically in Pennsylvania (PA), home to the Appalachian Orocline and 5 distinct tectonic provinces. Using hillshades from a digital elevation model (DEM) of PA, we manually pick all topographic lineaments 1 km or greater, discriminating only against man-made structures. The final lineament coverage of the state is subdivided into smaller areas for which rose diagrams were prepared. The dominant lineament trends were compared and associated with known structural features. Peaks with no known source are marked as possible tectonic features requiring further research. A domain analysis is performed on the lineament data to identify the extent and interplay of swarms, followed by an investigation of their azimuthal compatibility. We present the results of our domain analysis of all topographic lineaments in the context of identifying litho-tectonic provinces associated with Appalachian tectonics in Pennsylvania, and possible heterogeneities within them.

A methodology for studying tectonic subsidence variations: insights from the Fernie Formation of west-central Alberta

NASA Astrophysics Data System (ADS)

McCartney, Tannis Maureen

Tectonic subsidence curves for over 300 subsurface wells in west-central Alberta indicate that the Western Canada Foreland Basin was initiated at the same time the lower units of the Fernie Formation were being deposited. This evidence is further supported by sedimentological data and fits with the timing of the onset of deformation in the Cordillera and the initiation of the foreland basin in Montana. The volume of subsidence curves in this study required an innovative methodology. Subsidence calculations were performed using customized macros in a spreadsheet. The tectonic subsidence variations were displayed in a tectonic subsidence envelope, which showed the total variation in the subsidence curves, and three suites of maps: tectonic subsidence, tectonic subsidence residuals, and tectonic subsidence ratios. Collectively, the maps of the tectonic subsidence in the Fernie Formation show that there was a western influence on subsidence during deposition of the oldest members of the Fernie Formation.

Analysis of causes of the eventual increment in climatic episodies in the period 2004-2014 and the consequences on the coast of Galicia (NW Spain)

NASA Astrophysics Data System (ADS)

Rodriguez Lopez, Fernando; Diez, Javier; Veiga, Efren

2015-04-01

In recent years has observed an increase in atmospheric and marine events on the coast of Galicia (Spain) which have caused economic losses and human lives; and also an alarm in the population. This work analyse the consequences in order temporal and geographical; and the possible causes and influences which can motivate the presence of these events and their consequences. This work also proposes a strategy to prevent such events and to limit their effects. The generating criteria proposed is a rating system of security, in such way that the society by itself generates the trends for improvement. Keywords: Security, Civil engineering, Marine constructions, Realibility, Insurance, Prevention forensic engineering

Performance Comparison of Feature Extraction Algorithms for Target Detection and Classification

DTIC Science & Technology

2013-01-01

Detection and Classification⋆ Soheil Bahrampour1 Asok Ray2 Soumalya Sarkar2 Thyagaraju Damarla3 Nasser M. Nasrabadi3 Keywords: Feature Extraction...USA email:soheil@psu.edu 2A. Ray and S. Sarkar are with the Department of Mechanical Engineering, Pennsylvania State University, University Park, PA...no. 1, pp. 22–29, 2001. [5] G. Mallapragada, A. Ray , and X. Jin, “Symbolic dynamic filtering and language measure for behavior identification of mobile

Quality of Health Information on the Internet for Urolithiasis on the Google Search Engine.

PubMed

Chang, Dwayne T S; Abouassaly, Robert; Lawrentschuk, Nathan

2016-01-01

Purpose . To compare the quality of health information on the Internet for keywords related to urolithiasis, to assess for difference in information quality across four main Western languages, and to compare the source of sponsorship in these websites. Methods . Health On the Net (HON) Foundation principles were utilised to determine quality information. Fifteen keywords related to urolithiasis were searched on the Google search engine. The first 150 websites were assessed against the HON principles and the source of sponsorship determined. Results . A total of 8986 websites were analysed. A proportion of HON-accredited websites for individual search terms range between 2.5% and 12.0%. The first 50 websites were more likely to be HON-positive compared to websites 51-100 and 101-150. French websites searched were more likely to be HON-positive whereas German websites were less likely to be HON-positive than English websites. There was no statistically significant difference between the rate of HON-positive English and Spanish websites. The three main website sponsors were from government/educational sources (40.2%), followed by commercial (29.9%) and physician/surgeon sources (18.6%). Conclusions . Health information on most urolithiasis websites was not validated. Nearly one-third of websites in this study have commercial sponsorship. Doctors should recognise the need for more reliable health websites for their patients.

Quantum geodesy

NASA Astrophysics Data System (ADS)

Jitrik, Oliverio; Lanzagorta, Marco; Uhlmann, Jeffrey; Venegas-Andraca, Salvador E.

2017-05-01

The study of plate tectonic motion is important to generate theoretical models of the structure and dynamics of the Earth. In turn, understanding tectonic motion provides insight to develop sophisticated models that can be used for earthquake early warning systems and for nuclear forensics. Tectonic geodesy uses the position of a network of points on the surface of earth to determine the motion of tectonic plates and the deformation of the earths crust. GPS and interferometric synthetic aperture radar are commonly used techniques used in tectonic geodesy. In this paper we will describe the feasibility of interferometric synthetic aperture quantum radar and its theoretical performance for tectonic geodesy.

Studies in geophysics: Active tectonics

NASA Technical Reports Server (NTRS)

1986-01-01

Active tectonics is defined within the study as tectonic movements that are expected to occur within a future time span of concern to society. Such movements and their associated hazards include earthquakes, volcanic eruptions, and land subsidence and emergence. The entire range of geology, geophysics, and geodesy is, to some extent, pertinent to this topic. The needs for useful forecasts of tectonic activity, so that actions may be taken to mitigate hazards, call for special attention to ongoing tectonic activity. Further progress in understanding active tectonics depends on continued research. Particularly important is improvement in the accuracy of dating techniques for recent geologic materials.

Why is understanding when Plate Tectonics began important for understanding Earth?

NASA Astrophysics Data System (ADS)

Korenaga, J.

2015-12-01

Almost all kinds of geological activities on Earth depend critically on the operation of plate tectonics, but did plate tectonics initiate right after the solidification of a putative magma ocean, or did it start much later, e.g., sometime during the Archean? This problem of the initiation of plate tectonics in the Earth history presents us a unique combination of observational and theoretical challenges. Finding geological evidence for the onset of plate tectonics is difficult because plate tectonics is a dynamic process that continuously destroys a remnant of the past. We therefore need to rely on more secondary traces, the interpretation of which often involves theoretical considerations. At the same time, it is still hard to predict, on a firm theoretical ground, when plate tectonics should have prevailed, because there is no consensus on why plate tectonics currently takes place on Earth. Knowing when plate tectonics began is one thing, and understanding why it did so is another. The initiation of plate tectonics is one of the last frontiers in earth science, which encourages a concerted effort from both geologists and geophysicists to identify key geological evidence and distinguish between competing theories of early Earth evolution. Such an endeavor is essential to arrive at a self-contained theory for the evolution of terrestrial planets.

Geologic and tectonic characteristics of rockbursts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adushkin, V.V.; Charlamov, V.A.; Kondratyev, S.V.

1995-06-01

The modern mining enterprises have attained such scales of engineering activity that their direct influence to a rock massif and in series of cases to the region seismic regime doesn`t provoke any doubts. Excavation and removal of large volumes of rock mass, industrial explosions and other technological factors during long time can lead to the accumulation of man-made changes in rock massifs capable to cause catastrophic consequences. The stress state changes in considerable domains of massif create dangerous concentration of stresses at large geological heterogeneities - faults localized in the mining works zone. External influence can lead in that casemore » to such phenomena as tectonic rockbursts and man-made earthquakes. The rockbursts problem in world mining practice exists for more than two hundred years. So that its actuality not only doesn`t decrease but steadily mounts up as due to the mining works depth increase, enlargement of the useful minerals excavations volumes as due to the possibility of safe use of the rock massif potential energy for facilitating the mastering of the bowels of the Earth and for making that more cheap. The purpose of present work is to study the engineering activity influence to processes occurring in the upper part of Earth crust and in particular in a rock massif. The rock massif is treated in those studies as a geophysical medium - such approach takes into account the presence of block structure of medium and the continuous exchange of energy between parts of that structure. The idea ``geophysical medium`` is applied in geophysics sufficiently wide and stresses the difference of actual Earth crust and rock massifs from the continuous media models discussed in mechanics.« less

Influence of Tectonics on the Channel Pattern of Alaknanda River in Srinagar Valley (Garhwal Himalaya)

NASA Astrophysics Data System (ADS)

Datt, Devi

2017-04-01

This paper describes the results of a continuing investigation of tectonic influence on channel pattern and morphology of Alaknanda River in Lesser Garhwal Himalaya, Uttarakhand, India. Extensive field investigations using conventional methods supported by topographical sheets and remote sensing data (LISS IV), were undertaken.The results are classified into three sections :- tectonics, channel pattern and impact of tectonics on channel pattern. The channel length is divided into 8 meanders sets of 3 segments from Supana to Kirtinagar. Thereafter, a litho-tectonic map of the Srinagar valley was prepared. The style of active tectonics on deformation and characterization of fluvial landscape was investigated on typical strike-slip transverse faults near the zone of North Almora Thrust (NAT). NAT is a major tectonic unit of the Lesser Himalaya which passes through the northern margin from NW to SE direction.. The structural and lithological controls on the Alaknanda River system in Srinagar valley are reflected on distinct drainage patterns, abrupt change in flow direction, incised meandering, offset river channels, straight river lines, palaeo-channels, multi levels of terraces, knick points and pools in longitudinal profile. The results of the study show that the sinuosity index of the river is 1.35. Transverse faulting is very common along the NAT. An earlier generation of linear tectonic features were displaced by the latter phase of deformation. Significant deviations were observed in river channel at deformation junctions. Moreover, all 8 sets of meanders are strongly influenced by tectonic features. The meandering course is, thereby, correlated with tectonic features. It is shown that the river channel is strongly influenced by the tectonic features in the study area. Key Words: Tectonic, Meander, Channel pattern, deformation, Knick point.

Examining the Personal Nature of the K-14 Engineering Pipeline for Young Women

NASA Astrophysics Data System (ADS)

Gurski, Jennifer Sue

This mixed-methods study examined young women's perceptions of their K-14 STEM pipeline experiences and their resulting choice to enter and persist in an engineering major. Despite the increase of women in the STEM workforce, women remain underrepresented among engineering majors (Beasley & Fischer, 2012; Heilbronner, 2012; Neihart & Teo, 2013). Few studies exist that utilize a retrospective approach to understand how the culmination of young women's K-14 experiences have influenced their formation of individually held perceptions that lead to engineering persistence. It is this study's aim to utilize a mixed-methods approach to answer the following research question: How do young women's perceptions of their K-14 STEM experiences influence their decision to enroll and persist in an engineering major? These perceptions are explored through an ethnographic approach focusing on young women enrolled in engineering programs during their junior and senior years of study at a small private liberal arts university with eight engineering majors. The mixed-methods approach follows a sequential design method (Creswell, 2013) and utilizes questions in a quantitative Likert-type survey from the Academic Pathways for People Learning Engineering (APPLES) survey (Eris, Chachra, Chen, Sheppard, & Ludlow, 2010) and the Motivated Strategy Learning Questionnaire (MSLQ) (Pintrich, Smith, Garcia, & McKeachie, 1991). The quantitative study results will lead to the development of open-ended, structured questions for conducting a qualitative focus group. Anonymity of all participants is maintained. Keywords: STEM, young women, perceptions, pipeline, intervention, underrepresentation, engineering, persistence, retrospective, self-efficacy.

Structural evolution of Halaban Area, Eastern Arabian Shield, Saudi Arabia

NASA Astrophysics Data System (ADS)

Al-Amri, Yousef; Kassem1, Osama M. K.

2017-04-01

Neoproterozoic basement complex comprises a metamorphic/igneous suite (Abt schist and sheared granitoids) with syn-accretionary transpressive structures, unconformably overlain by a post-amalgamation volcanosedimentary sequence. This study aims to attempt to exposed post-accretionary thrusting and thrust-related structures at Halaban area, Eastern Arabian Shield. The Rf/ϕ and Fry methods are utilized on quartz and feldspar porphyroclasts, as well as on mafic crystals, such as hornblende and biotite, in eighteen samples. The X/Z axial ratios range from 1.12 to 4.99 for Rf/ϕ method and from 1.65 to 4.00 for Fry method. The direction of finite strain for the long axes displays clustering along the WNW trend (occasionally N) with slight plunging. Finite strain accumulated without any significant volume change contemporaneously with syn-accretionary transpressive structures. It indicates that the contacts between various lithological units in the Halaban area were formed under brittle to semi-ductile deformation conditions. The penetrative subhorizontal foliation was concurrent with thrusting and shows nearly the same attitudes of tectonic contacts with the overlying nappes. Keywords: Finite strain analysis, volcanosedimentary sequence, Halaban area, Eastern Arabian Shield, Saudi Arabia.

The role of tectonic damage and brittle rock fracture in the development of large rock slope failures

NASA Astrophysics Data System (ADS)

Brideau, Marc-André; Yan, Ming; Stead, Doug

2009-01-01

Rock slope failures are frequently controlled by a complex combination of discontinuities that facilitate kinematic release. These discontinuities are often associated with discrete folds, faults, and shear zones, and/or related tectonic damage. The authors, through detailed case studies, illustrate the importance of considering the influence of tectonic structures not only on three-dimensional kinematic release but also in the reduction of rock mass properties due to induced damage. The case studies selected reflect a wide range of rock mass conditions. In addition to active rock slope failures they include two major historic failures, the Hope Slide, which occurred in British Columbia in 1965 and the Randa rockslides which occurred in Switzerland in 1991. Detailed engineering geological mapping combined with rock testing, GIS data analysis and for selected case numerical modelling, have shown that specific rock slope failure mechanisms may be conveniently related to rock mass classifications such as the Geological Strength Index (GSI). The importance of brittle intact rock fracture in association with pre-existing rock mass damage is emphasized though a consideration of the processes involved in the progressive-time dependent development not only of though-going failure surfaces but also lateral and rear-release mechanisms. Preliminary modelling data are presented to illustrate the importance of intact rock fracture and step-path failure mechanisms; and the results are discussed with reference to selected field observations. The authors emphasize the importance of considering all forms of pre-existing rock mass damage when assessing potential or operative failure mechanisms. It is suggested that a rock slope rock mass damage assessment can provide an improved understanding of the potential failure mode, the likely hazard presented, and appropriate methods of both analysis and remedial treatment.

Hydrogeologic Framework of the Salt Basin, New Mexico and Texas

NASA Astrophysics Data System (ADS)

Ritchie, A. B.; Phillips, F. M.

2010-12-01

The Salt Basin is a closed drainage basin located in southeastern New Mexico (Otero, Chaves, and Eddy Counties), and northwestern Texas (Hudspeth, Culberson, Jeff Davis, and Presidio Counties), which can be divided into a northern and a southern system. Since the 1950s, extensive groundwater withdrawals have been associated with agricultural irrigation in the Dell City, Texas region, just south of the New Mexico-Texas border. Currently, there are three major applications over the appropriations of groundwater in the Salt Basin. Despite these factors, relatively little is known about the recharge rates and storage capacity of the basin, and the estimates that do exist are highly variable. The Salt Basin groundwater system was declared by the New Mexico State Engineer during 2002 in an attempt to regulate and control growing interest in the groundwater resources of the basin. In order to help guide long-term management strategies, a conceptual model of groundwater flow in the Salt Basin was developed by reconstructing the tectonic forcings that have affected the basin during its formation, and identifying the depositional environments that formed and the resultant distribution of facies. The tectonic history of the Salt Basin can be divided into four main periods: a) Pennsylvanian-to-Early Permian, b) Mid-to-Late Permian, c) Late Cretaceous, and d) Tertiary-to-Quaternary. Pennsylvanian-to-Permian structural features affected deposition throughout the Permian, resulting in three distinct hydrogeologic facies: basin, shelf-margin, and shelf. Permian shelf facies rocks form the primary aquifer within the northern Salt Basin, although minor aquifers occur in Cretaceous rocks and Tertiary-to-Quaternary alluvium. Subsequent tectonic activity during the Late Cretaceous resulted in the re-activation of many of the earlier structures. Tertiary-to-Quaternary Basin-and-Range extension produced the current physiographic form of the basin.

Design of bridges against large tectonic deformation

NASA Astrophysics Data System (ADS)

Anastasopoulos, I.; Gazetas, G.; Drosos, V.; Georgarakos, T.; Kourkoulis, R.

2008-12-01

The engineering community has devoted much effort to understanding the response of soil-structure systems to seismic ground motions, but little attention to the effects of an outcropping fault offset. The 1999 earthquakes of Turkey and Taiwan, offering a variety of case histories of structural damage due to faulting, have (re)fueled the interest on the subject. This paper presents a methodology for design of bridges against tectonic deformation. The problem is decoupled in two analysis steps: the first (at the local level) deals with the response of a single pier and its foundation to fault rupture propagating through the soil, and the superstructure is modeled in a simplified manner; and the second (at the global level) investigates detailed models of the superstructure subjected to the support (differential) displacements of Step 1. A parametric study investigates typical models of viaduct and overpass bridges, founded on piles or caissons. Fixed-head piled foundations are shown to be rather vulnerable to faulting-induced deformation. End-bearing piles in particular are unable to survive bedrock offsets exceeding 10 cm. Floating piles perform better, and if combined with hinged pile-to-cap connections, they could survive much larger offsets. Soil resilience is beneficial in reducing pile distress. Caisson foundations are almost invariably successful. Statically-indeterminate superstructures are quite vulnerable, while statically-determinate are insensitive (allowing differential displacements and rotations without suffering any distress). For large-span cantilever-construction bridges, where a statically determinate system is hardly an option, inserting resilient seismic isolation bearings is advantageous as long as ample seating can prevent the deck from falling off the supports. An actual application of the developed method is presented for a major bridge, demonstrating the feasibility of design against tectonic deformation.

Improving global paleogeographic reconstructions since the Devonian using paleobiology

NASA Astrophysics Data System (ADS)

Cao, Wenchao; Zahirovic, Sabin; Williams, Simon; Flament, Nicolas; Müller, Dietmar

2017-04-01

Paleogeographic reconstructions are important to understand past eustatic and regional sea level change, the tectonic evolution of the planet, hydrocarbon genesis, and to constrain and interpret the dynamic topography predicted by time-dependent global mantle convection models. Several global paleogeographic compilations have been published, generally presented as static snapshots with varying temporal resolution and fixed spatial resolution. Published paleogeographic compilations are tied to a particular plate motion model, making it difficult to link them to alternative digital plate tectonic reconstructions. In order to address this issue, we developed a workflow to reverse-engineer reconstructed paleogeographies to their present-day coordinates and link them to any reconstruction model. Published paleogeographic compilations are also tied to a given dataset. We used fossil data from the Paleobiology Database to identify inconsistencies between fossils paleoenvironments and paleogeographic reconstructions, and to improve reconstructed terrestrial-marine boundaries by resolving these inconsistencies. We used the improved reconstructed paleogeographies to estimate the surface areas of global paleogeographic features (shallow marine environments, landmasses, mountains and ice sheets), to investigate the global continental flooding history since the late Paleozoic, which has inherent links to global eustasy as well as dynamic topography. Finally, we discuss the relationships between our modeled emerged land area and total continental area through time, continental growth models, and strontium isotope (87Sr/86Sr) signatures in ocean water. Our study highlights the flexibility of digital paleogeographic models linked to state-of-the-art plate tectonic reconstructions in order to better understand the interplay of continental growth and eustasy, with wider implications for understanding Earth's paleotopography, ocean circulation, and the role of mantle convection in shaping long-wavelength topography.

Layers and Fractures in Ophir Chasma

NASA Image and Video Library

2015-11-05

Ophir Chasma forms the northern portion of Valles Marineris, and this image from NASA Mars Reconnaissance Orbiter spacecraft features a small part of its wall and floor. The wall rock shows many sedimentary layers and the floor is covered with wind-blown ridges, which are intermediate in size between sand ripples and sand dunes. Rocks protruding on the floor could be volcanic intrusions of once-molten magma that have pushed aside the surrounding sedimentary layers and "froze" in place. Images like this can help geologists study the formation mechanisms of large tectonic systems like Valles Marineris. (The word "tectonics" does not mean the same thing as "plate tectonics." Tectonics simply refers to large stresses and strains in a planet's crust. Plate tectonics is the main type of tectonics that Earth has; Mars does not have plate tectonics.) http://photojournal.jpl.nasa.gov/catalog/PIA20044

Accessibility, nature and quality of health information on the Internet: a survey on osteoarthritis.

PubMed

Maloney, S; Ilic, D; Green, S

2005-03-01

This study aims to determine the quality and validity of information available on the Internet about osteoarthritis and to investigate the best way of sourcing this information. Keywords relevant to osteoarthritis were searched across 15 search engines representing medical, general and meta-search engines. Search engine efficiency was defined as the percentage of unique and relevant websites from all websites returned by each search engine. The quality of relevant information was appraised using the DISCERN tool and the concordance of the information offered by the website with the available evidence about osteoarthritis determined. A total of 3443 websites were retrieved, of which 344 were identified as unique and providing information relevant to osteoarthritis. The overall quality of website information was poor. There was no significant difference between types of search engine in sourcing relevant information; however, the information retrieved from medical search engines was of a higher quality. Fewer than a third of the websites identified as offering relevant information cited evidence to support their recommendations. Although the overall quality of website information about osteoarthritis was poor, medical search engines may provide consumers with the opportunity to source high-quality health information on the Internet. In the era of evidence-based medicine, one of the main obstacles to the Internet reaching its potential as a medical resource is the failure of websites to incorporate and attribute evidence-based information.

Anthropogenic sea level rise and adaptation in the Yangtze estuary

NASA Astrophysics Data System (ADS)

Cheng, H.; Chen, J.; Chen, Z.; Ruan, R.; Xu, G.; Zeng, G.; Zhu, J.; Dai, Z.; Gu, S.; Zhang, X.; Wang, H.

2016-02-01

Sea level rise is a major projected threat of climate change. There are regional variations in sea level changes, depending on both naturally the tectonic subsidence, geomorphology, naturally changing river inputs and anthropogenic driven forces as artificial reservoir water impoundment within the watershed and urban land subsidence driven by ground water depletion in the river delta. Little is known on regional sea level fall in response to the channel erosion due to the sediment discharge decline by reservoir interception in the upstream watershed, and water level rise driven by anthropogenic measures as the land reclamation, deep waterway regulation and fresh water reservoir construction to the sea level change in estuaries. Changing coastal cities are situated in the delta regions expected to be threatened in various degrees. Shanghai belongs to those cities. Here we show that the anthropogenic driven sea level rise in the Yangtze estuary from the point of view of the continuous hydrodynamic system consisted of river catchment, estuary and coastal sea. Land subsidence is cited as 4 mm/a (2011-2030). Scour depth of the estuarine channel by upstream engineering as Three Gauge Dam is estimated at 2-10 cm (2011-2030). The rise of water level by deep waterway and land reclamation is estimated at 8-10 cm (2011-2030). The relative sea level rise will be speculated about 10 -16 cm (2011-2030), which these anthropogenic sea level changes will be imposed into the absolute sea level rise 2 mm/a and tectonic subsidence 1 mm/a measured in 1990s. The action guideline to the sea level rise strategy in the Shanghai city have been proposed to the Shanghai government as (1) recent actions (2012-2015) to upgrade the city water supply and drainage engineering and protective engineering; (2) interim actions (2016-2020) to improve sea level monitoring and early warning system, and then the special, city, regional planning considering sea level rise; (3) long term actions (2021-2030) to implement both the safety and the transformation and development of the city.

Summaries of the thematic conferences on remote sensing for exploration geology

NASA Technical Reports Server (NTRS)

1989-01-01

The Thematic Conference series was initiated to address the need for concentrated discussion of particular remote sensing applications. The program is primarily concerned with the application of remote sensing to mineral and hydrocarbon exploration, with special emphasis on data integration, methodologies, and practical solutions for geologists. Some fifty invited papers are scheduled for eleven plenary sessions, formulated to address such important topics as basement tectonics and their surface expressions, spectral geology, applications for hydrocarbon exploration, and radar applications and future systems. Other invited presentations will discuss geobotanical remote sensing, mineral exploration, engineering and environmental applications, advanced image processing, and integration and mapping.

Lasting mantle scars lead to perennial plate tectonics.

PubMed

Heron, Philip J; Pysklywec, Russell N; Stephenson, Randell

2016-06-10

Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a 'perennial' phenomenon.

Lasting mantle scars lead to perennial plate tectonics

PubMed Central

Heron, Philip J.; Pysklywec, Russell N.; Stephenson, Randell

2016-01-01

Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a ‘perennial' phenomenon. PMID:27282541

Stress drops of induced and tectonic earthquakes in the central United States are indistinguishable.

PubMed

Huang, Yihe; Ellsworth, William L; Beroza, Gregory C

2017-08-01

Induced earthquakes currently pose a significant hazard in the central United States, but there is considerable uncertainty about the severity of their ground motions. We measure stress drops of 39 moderate-magnitude induced and tectonic earthquakes in the central United States and eastern North America. Induced earthquakes, more than half of which are shallower than 5 km, show a comparable median stress drop to tectonic earthquakes in the central United States that are dominantly strike-slip but a lower median stress drop than that of tectonic earthquakes in the eastern North America that are dominantly reverse-faulting. This suggests that ground motion prediction equations developed for tectonic earthquakes can be applied to induced earthquakes if the effects of depth and faulting style are properly considered. Our observation leads to the notion that, similar to tectonic earthquakes, induced earthquakes are driven by tectonic stresses.

Stress drops of induced and tectonic earthquakes in the central United States are indistinguishable

PubMed Central

Huang, Yihe; Ellsworth, William L.; Beroza, Gregory C.

2017-01-01

Induced earthquakes currently pose a significant hazard in the central United States, but there is considerable uncertainty about the severity of their ground motions. We measure stress drops of 39 moderate-magnitude induced and tectonic earthquakes in the central United States and eastern North America. Induced earthquakes, more than half of which are shallower than 5 km, show a comparable median stress drop to tectonic earthquakes in the central United States that are dominantly strike-slip but a lower median stress drop than that of tectonic earthquakes in the eastern North America that are dominantly reverse-faulting. This suggests that ground motion prediction equations developed for tectonic earthquakes can be applied to induced earthquakes if the effects of depth and faulting style are properly considered. Our observation leads to the notion that, similar to tectonic earthquakes, induced earthquakes are driven by tectonic stresses. PMID:28782040

Tectonic asymmetry of the earth and other planets

NASA Technical Reports Server (NTRS)

Pushcharovskiy, Y. M.; Kozlov, V. V.; Sulidi-Kondratyev, Y. D.

1978-01-01

The structures of Earth, Mars, Venus, and the Moon are examined and compared. Global tectonic characteristics are presented for each. A comparison of the tectonics reveals the structural asymetry of these planets and the moon. Tectonic asymmetry information for the group is used to interpret certain aspects of the earth's geological past.

Tectonic Evolution of Bell Regio, Venus: Regional Stress, Lithospheric Flexure, and Edifice Stresses

NASA Astrophysics Data System (ADS)

Rogers, P. G.; Zuber, M. T.

1996-03-01

Analyses of the tectonic features associated with large volcanoes provide important insight into the relationship between volcanic and tectonic processes and the stress state of a planet's crust over time, and provide constraints on the local and regional geologic evolution. This investigation focuses on the tectonism and volcanism of Bell Regio, a major highland uplift n Venus. The stress environments and resulting tectonic features associated with the major volcanic edifices in this region are examined using Magellan ynthetic aperture radar (SAR) images and altimeter measurements of topography. The major volcanoes of Bell Regio, Tepev Mons and the "Eastern Volcanic Center" (EVC), exhibit tectonic characteristics that are unique relative to other volcanic edifices on Venus. The most prominent distinctions are the lack of large rift zones within the overall highland uplift and the presence of radial tectonic and concentric fractures associated with the major edifices. This study examines the regional stress field in Bell Regio through analysis of structural features believed to be a consequence of lithospheric flexure due to volcanic loading and tectonic features that likely resulted from edifice stresses associated with magma chamber inflation.

An Object-oriented Computer Code for Aircraft Engine Weight Estimation

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Naylor, Bret A.

2008-01-01

Reliable engine-weight estimation at the conceptual design stage is critical to the development of new aircraft engines. It helps to identify the best engine concept amongst several candidates. At NASA Glenn (GRC), the Weight Analysis of Turbine Engines (WATE) computer code, originally developed by Boeing Aircraft, has been used to estimate the engine weight of various conceptual engine designs. The code, written in FORTRAN, was originally developed for NASA in 1979. Since then, substantial improvements have been made to the code to improve the weight calculations for most of the engine components. Most recently, to improve the maintainability and extensibility of WATE, the FORTRAN code has been converted into an object-oriented version. The conversion was done within the NASA s NPSS (Numerical Propulsion System Simulation) framework. This enables WATE to interact seamlessly with the thermodynamic cycle model which provides component flow data such as airflows, temperatures, and pressures, etc. that are required for sizing the components and weight calculations. The tighter integration between the NPSS and WATE would greatly enhance system-level analysis and optimization capabilities. It also would facilitate the enhancement of the WATE code for next-generation aircraft and space propulsion systems. In this paper, the architecture of the object-oriented WATE code (or WATE++) is described. Both the FORTRAN and object-oriented versions of the code are employed to compute the dimensions and weight of a 300- passenger aircraft engine (GE90 class). Both versions of the code produce essentially identical results as should be the case. Keywords: NASA, aircraft engine, weight, object-oriented

ON THE NOTION OF WELL-DEFINED TECTONIC REGIMES FOR TERRESTRIAL PLANETS IN THIS SOLAR SYSTEM AND OTHERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lenardic, A.; Crowley, J. W., E-mail: ajns@rice.edu, E-mail: jwgcrowley@gmail.com

2012-08-20

A model of coupled mantle convection and planetary tectonics is used to demonstrate that history dependence can outweigh the effects of a planet's energy content and material parameters in determining its tectonic state. The mantle convection-surface tectonics system allows multiple tectonic modes to exist for equivalent planetary parameter values. The tectonic mode of the system is then determined by its specific geologic and climatic history. This implies that models of tectonics and mantle convection will not be able to uniquely determine the tectonic mode of a terrestrial planet without the addition of historical data. Historical data exists, to variable degrees,more » for all four terrestrial planets within our solar system. For the Earth, the planet with the largest amount of observational data, debate does still remain regarding the geologic and climatic history of Earth's deep past but constraints are available. For planets in other solar systems, no such constraints exist at present. The existence of multiple tectonic modes, for equivalent parameter values, points to a reason why different groups have reached different conclusions regarding the tectonic state of extrasolar terrestrial planets larger than Earth ({sup s}uper-Earths{sup )}. The region of multiple stable solutions is predicted to widen in parameter space for more energetic mantle convection (as would be expected for larger planets). This means that different groups can find different solutions, all potentially viable and stable, using identical models and identical system parameter values. At a more practical level, the results argue that the question of whether extrasolar terrestrial planets will have plate tectonics is unanswerable and will remain so until the temporal evolution of extrasolar planets can be constrained.« less

Human Factors Evaluations of Two-Dimensional Spacecraft Conceptual Layouts

NASA Technical Reports Server (NTRS)

Kennedy, Kriss J.; Toups, Larry D.; Rudisill, Marianne

2010-01-01

Much of the human factors work done in support of the NASA Constellation lunar program has been with low fidelity mockups. These volumetric replicas of the future lunar spacecraft allow researchers to insert test subjects from the engineering and astronaut population and evaluate the vehicle design as the test subjects perform simulations of various operational tasks. However, lunar outpost designs must be evaluated without the use of mockups, creating a need for evaluation tools that can be performed on two-dimension conceptual spacecraft layouts, such as floor plans. A tool based on the Cooper- Harper scale was developed and applied to one lunar scenario, enabling engineers to select between two competing floor plan layouts. Keywords: Constellation, human factors, tools, processes, habitat, outpost, Net Habitable Volume, Cooper-Harper.

[Title, abstract and keywords: essential issues in medical bibliographic research].

PubMed

Bonciu, Carmen

2005-01-01

Medical information, conveyed either by books, journal articles, conference and congress papers or posters, represents the product, the result of the medical research. Note that the informational cycle can be shown schematically as Bibliographic information --> Medical research --> Research results --> Bibliographic information. The result of the scientific research (articles, posters, etc.) re-enters the informational cycle, as bibliographic information for a new medical research. The bibliographic research is still a time, and effort consuming activity, despite the explosive growth of information technology. It requires specific medical, information technology and bibliographic knowledge. The present work aims to emphasize the importance of title, keywords and abstract terms selection, to article writing and publication in medical journals, and the proper choice of meta-information in web pages. The bibliographic research was made using two databases with English language information about articles from international medical journals: MEDLINE (PUBMED) and PROQUEST MEDICAL LIBRARY. The results were compared with GOOGLE and YAHOO search. These searching engines are common now in all types of Internet users (including researchers, librarians, etc.). It is essential for the researchers to know the article registration mechanism in a database and the modalities of bibliographic investigation of online databases, so that the title, keyword and abstract terms are selected properly. The use of words not related to the subject, in title, keywords or abstract, results in ambiguities. The writing and the translation of scientific words must also be accurate, mainly when article authors are non-native English speakers: e.g., chimiotherapy (sic)--20 articles in Medline, 270 articles in Google; morphopathology (sic)-- 78 articles in Medline, and 294 in Google; morphopatology (sic)--2 articles in Medline, and 12 articles in Google.

Comparative Study of the academic performance between different curricula in Agricultural Engineering

NASA Astrophysics Data System (ADS)

Vazquez, J. L.; Serrano, A.; Caniego, J.

2012-04-01

Due to the introduction of new degrees on the College of Agricultural Engineering of the Technical University of Madrid adapted to the European Space for Higher Education (Bologna), we have made a comparative study of academic achievement obtained by the students during their first year at the Centre according to different curricula. We used data from 2 curricula leading to the degree in Agricultural Engineering, Curriculumn 74 (6 years and annual structure) and Curriculum 96 modified in 2006 (5 years with quarterly structure) and the new curriculum in grades (4 years semi-structured). It has been used as a data source, the qualifications of new students during the last three years prior to the extinction of the curriculum.The study shows that current rates of academic success or failure and dropout during the first year of college are very similar to those happening 12 years ago, when it was assumed that the preparation of students from high school was much higher than today. Keywords: Academic performance, curricula, Bologna.

A Firefly Algorithm-based Approach for Pseudo-Relevance Feedback: Application to Medical Database.

PubMed

Khennak, Ilyes; Drias, Habiba

2016-11-01

The difficulty of disambiguating the sense of the incomplete and imprecise keywords that are extensively used in the search queries has caused the failure of search systems to retrieve the desired information. One of the most powerful and promising method to overcome this shortcoming and improve the performance of search engines is Query Expansion, whereby the user's original query is augmented by new keywords that best characterize the user's information needs and produce more useful query. In this paper, a new Firefly Algorithm-based approach is proposed to enhance the retrieval effectiveness of query expansion while maintaining low computational complexity. In contrast to the existing literature, the proposed approach uses a Firefly Algorithm to find the best expanded query among a set of expanded query candidates. Moreover, this new approach allows the determination of the length of the expanded query empirically. Experimental results on MEDLINE, the on-line medical information database, show that our proposed approach is more effective and efficient compared to the state-of-the-art.

Plate Tectonics: A Paradigm under Threat.

ERIC Educational Resources Information Center

Pratt, David

2000-01-01

Discusses the challenges confronting plate tectonics. Presents evidence that contradicts continental drift, seafloor spreading, and subduction. Reviews problems posed by vertical tectonic movements. (Contains 242 references.) (DDR)

Tectonic models for Yucca Mountain, Nevada

USGS Publications Warehouse

O'Leary, Dennis W.

2006-01-01

Performance of a high-level nuclear waste repository at Yucca Mountain hinges partly on long-term structural stability of the mountain, its susceptibility to tectonic disruption that includes fault displacement, seismic ground motion, and igneous intrusion. Because of the uncertainty involved with long-term (10,000 yr minimum) prediction of tectonic events (e.g., earthquakes) and the incomplete understanding of the history of strain and its mechanisms in the Yucca Mountain region, a tectonic model is needed. A tectonic model should represent the structural assemblage of the mountain in its tectonic setting and account for that assemblage through a history of deformation in which all of the observed deformation features are linked in time and space. Four major types of tectonic models have been proposed for Yucca Mountain: a caldera model; simple shear (detachment fault) models; pure shear (planar fault) models; and lateral shear models. Most of the models seek to explain local features in the context of well-accepted regional deformation mechanisms. Evaluation of the models in light of site characterization shows that none of them completely accounts for all the known tectonic features of Yucca Mountain or is fully compatible with the deformation history. The Yucca Mountain project does not endorse a preferred tectonic model. However, most experts involved in the probabilistic volcanic hazards analysis and the probabilistic seismic hazards analysis preferred a planar fault type model. ?? 2007 Geological Society of America. All rights reserved.

Current deformation in the Tibetan Plateau: a stress gauge in the large-scale India-Asia collision tectonics

NASA Astrophysics Data System (ADS)

Capitanio, F. A.

2017-12-01

The quantification of the exact tectonic forces budget on Earth has remained thus far elusive. Geodetic velocities provide relevant constraints on the current dynamics of the coupling between collision and continental tectonics, however in the Tibetan plateau these support contrasting, non-unique models. Here, we compare numerical models of coupled India-Asia plate convergence, collision and continent interiors tectonics to the geodetically-constrained motions in the Tibetan Plateau to provide a quantitative assessment of the driving forces of plate tectonics in the area. The models develop a range of long-term evolutions remarkably similar to the Asian tectonics in the Cenozoic, reproducing the current large-scale motions pattern under a range of conditions. Balancing the convergent margin forces, following subduction, and the far-field forcing along the trail of the subducting continent, the geodetic rates in the Tibetan Plateau can be matched. The comparisons support the discussion on the likely processes at work, allowing inferences on the drivers of plateau formation and its role on the plate margin-interiors tectonics. More in general, the outcomes highlight the unique role of the Tibetan Plateau as a pressure gauge for the tectonic forces on Earth.

Plate tectonics on the Earth triggered by plume-induced subduction initiation.

PubMed

Gerya, T V; Stern, R J; Baes, M; Sobolev, S V; Whattam, S A

2015-11-12

Scientific theories of how subduction and plate tectonics began on Earth--and what the tectonic structure of Earth was before this--remain enigmatic and contentious. Understanding viable scenarios for the onset of subduction and plate tectonics is hampered by the fact that subduction initiation processes must have been markedly different before the onset of global plate tectonics because most present-day subduction initiation mechanisms require acting plate forces and existing zones of lithospheric weakness, which are both consequences of plate tectonics. However, plume-induced subduction initiation could have started the first subduction zone without the help of plate tectonics. Here, we test this mechanism using high-resolution three-dimensional numerical thermomechanical modelling. We demonstrate that three key physical factors combine to trigger self-sustained subduction: (1) a strong, negatively buoyant oceanic lithosphere; (2) focused magmatic weakening and thinning of lithosphere above the plume; and (3) lubrication of the slab interface by hydrated crust. We also show that plume-induced subduction could only have been feasible in the hotter early Earth for old oceanic plates. In contrast, younger plates favoured episodic lithospheric drips rather than self-sustained subduction and global plate tectonics.

Numerical simulation of phenomenon on zonal disintegration in deep underground mining in case of unsupported roadway

NASA Astrophysics Data System (ADS)

Han, Fengshan; Wu, Xinli; Li, Xia; Zhu, Dekang

2018-02-01

Zonal disintegration phenomenon was found in deep mining roadway surrounding rock. It seriously affects the safety of mining and underground engineering and it may lead to the occurrence of natural disasters. in deep mining roadway surrounding rock, tectonic stress in deep mining roadway rock mass, horizontal stress is much greater than the vertical stress, When the direction of maximum principal stress is parallel to the axis of the roadway in deep mining, this is the main reasons for Zonal disintegration phenomenon. Using ABAQUS software to numerical simulation of the three-dimensional model of roadway rupture formation process systematically, and the study shows that when The Direction of maximum main stress in deep underground mining is along the roadway axial direction, Zonal disintegration phenomenon in deep underground mining is successfully reproduced by our numerical simulation..numerical simulation shows that using ABAQUA simulation can reproduce Zonal disintegration phenomenon and the formation process of damage of surrounding rock can be reproduced. which have important engineering practical significance.

Neotectonic control on drainage systems: GIS-based geomorphometric and morphotectonic assessment for Crete, Greece

NASA Astrophysics Data System (ADS)

Argyriou, Athanasios V.; Teeuw, Richard M.; Soupios, Pantelis; Sarris, Apostolos

2017-11-01

Geomorphic indices can be used to examine the geomorphological and tectonic processes responsible for the development of the drainage basins. Such indices can be dependent on tectonics, erosional processes and other factors that control the morphology of the landforms. The inter-relationships between geomorphic indices can determine the influence of regional tectonic activity in the shape development of drainage basins. A Multi-Criteria Decision Analysis (MCDA) procedure has been used to perform an integrated cluster analysis that highlights information associated with the dominant regional tectonic activity. Factor Analysis (FA) and Analytical Hierarchy Process (AHP) were considered within that procedure, producing a representation of the distributed regional tectonic activity of the drainage basins studied. The study area is western Crete, located in the outer fore-arc of the Hellenic subduction zone, one of the world's most tectonically active regions. The results indicate that in the landscape evolution of the study area (especially the western basins) tectonic controls dominate over lithological controls.

Tectonic characterization of a potential high-level nuclear waste repository at Yucca Mountain, Nevada

USGS Publications Warehouse

Whitney, John W.; O'Leary, Dennis W.

1993-01-01

Tectonic characterization of a potential high-level nuclear waste repository at Yucca Mountain, Nevada, is needed to assess seismic and possible volcanic hazards that could affect the site during the preclosure (next 100 years) and the behavior of the hydrologic system during the postclosure (the following 10,000 years) periods. Tectonic characterization is based on assembling mapped geological structures in their chronological order of development and activity, and interpreting their dynamic interrelationships. Addition of mechanistic models and kinematic explanations for the identified tectonic processes provides one or more tectonic models having predictive power. Proper evaluation and application of tectonic models can aid in seismic design and help anticipate probable occurrence of future geologic events of significance to the repository and its design.

University degrees consistent with agricultural production in the European Union

NASA Astrophysics Data System (ADS)

Perdigones, Alicia; del Cerro, Jesus; Tarquis, Ana Maria; Benedicto, Susana; García, Jose Luis

2013-04-01

Degrees clearly oriented to rural and agricultural engineering are distinguished from the rest of the engineering areas by the need to involve the biological phenomena of engineering calculations. These degrees, which include subjects such as crop production, biotechnology and physics, among others, have evolved tremendously over the last ten years, implanting new curricula and introducing new specialties such as those dedicated to the environment or rural development, thereby adapting new social, economic and environmental aspects of each country. Currently being finalized to implement new titles in most Spanish universities, and in rest of Europe, following the guidelines set by Bologna. The process of elaboration of these degrees is complicated precisely because of the great variety of areas and subjects involved in these degrees. In this paper we study, for several countries of the European Union, the core subjects of the university degrees of agricultural engineering and the correlations between the core contents and the importance of the related uses of the soil in the different sectors of crop production (arable crops, horticulture, fruit growing, gardening, etc.) as well as other socio-economic criteria. The objective is to detect if the design of the core content is consistent in each country with the importance of the related socio-economic sector. Key-words: curriculum, crop production, agricultural engineer.

Tectonism

NASA Image and Video Library

2011-10-24

This image from NASA 2001 Mars Odyssey spacecraft shows evidence of tectonic stresses that deform and fracture rocks and planetary surfaces. Right angles seen here are a good indication that the feature was formed by tectonic stresses.

Tectonic Plates of China

DTIC Science & Technology

1977-04-01

C. Sun and Ta-iang Teng Contractor: University of Southern California Principal Investigator: Professor Ta-liang Teng (213) 746-6124 Contract Number...83 i" I. INTRODUCTION Over the vast Chinese mainland, one of the most interesting and dynamic regions of the world, complex tectonics, coupled with...west Pacific and the Alpine- Himalaya tectonic belts, the multitude of Chinese tectonic com- plexities is evident from its enormous topographic relief

Optimal Planet Properties For Plate Tectonics Through Time And Space

NASA Astrophysics Data System (ADS)

Stamenkovic, Vlada; Seager, Sara

2014-11-01

Both the time and the location of planet formation shape a rocky planet’s mass, interior composition and structure, and hence also its tectonic mode. The tectonic mode of a planet can vary between two end-member solutions, plate tectonics and stagnant lid convection, and does significantly impact outgassing and biogeochemical cycles on any rocky planet. Therefore, estimating how the tectonic mode of a planet is affected by a planet’s age, mass, structure, and composition is a major step towards understanding habitability of exoplanets and geophysical false positives to biosignature gases. We connect geophysics to astronomy in order to understand how we could identify and where we could find planet candidates with optimal conditions for plate tectonics. To achieve this goal, we use thermal evolution models, account for the current wide range of uncertainties, and simulate various alien planets. Based on our best model estimates, we predict that the ideal targets for plate tectonics are oxygen-dominated (C/O<1) (solar system like) rocky planets of ~1 Earth mass with surface oceans, large metallic cores super-Mercury, rocky body densities of ~7000kgm-3), and with small mantle concentrations of iron 0%), water 0%), and radiogenic isotopes 10 times less than Earth). Super-Earths, undifferentiated planets, and especially hypothetical carbon planets, speculated to consist of SiC and C, are not optimal for the occurrence of plate tectonics. These results put Earth close to an ideal compositional and structural configuration for plate tectonics. Moreover, the results indicate that plate tectonics might have never existed on planets formed soon after the Big Bang—but instead is favored on planets formed from an evolved interstellar medium enriched in iron but depleted in silicon, oxygen, and especially in Th, K, and U relative to iron. This possibly sets a belated Galactic start for complex Earth-like surface life if plate tectonics significantly impacts the build up and regulation of gases relevant for life. This allows for the first time to discuss the tectonic mode of a rocky planet from a practical astrophysical perspective.

Ultrasonic constraint of the microfracture anisotropy of flysch rocks from the Podhale Synclinorium (Poland)

NASA Astrophysics Data System (ADS)

Kłopotowska, Agnieszka

2018-01-01

This paper attempts to show the relationship between joints observed in flysch formations in the field and microfracture fabrics invisible to the naked eye in hand specimens. Ultrasonic measurements demonstrate that the intensity and orientations of domains "memorised" by rock specimens are associated with the historical stresses within the rock mass rather than the rock lamination. The spatial orientations of these microfractures have been measured, and their dynamic-elastic properties have been found to correlate with the orientation of macroscopic joint sets measured in the field. The elastic properties measured vary because of sedimentary diagenetic processes that occured during the tectonic deformations of these flysch rocks in the Podhale Synclinorium of Poland. The structural discontinuities detected by ultrasonic measurements can be perceived as an incipient phase of the macroscopic joints already visible in the field and are attributed to the in situ residual tectonic stresses. Such historical stresses impart a hidden mechanical anisotropy to the entire flysch sequence. The microfractures will develop into macroscopic joints during future relaxation of the exposed rock mass. Understanding the nature and orientation of the invisible microfracture anisotropy that will become macroscopic in the future is vital for the safe and efficient engineering of any rock mass.

This dynamic earth: the story of plate tectonics

USGS Publications Warehouse

Kious, W. Jacquelyne; Tilling, Robert I.

1996-01-01

In the early 1960s, the emergence of the theory of plate tectonics started a revolution in the earth sciences. Since then, scientists have verified and refined this theory, and now have a much better understanding of how our planet has been shaped by plate-tectonic processes. We now know that, directly or indirectly, plate tectonics influences nearly all geologic processes, past and present. Indeed, the notion that the entire Earth's surface is continually shifting has profoundly changed the way we view our world.People benefit from, and are at the mercy of, the forces and consequences of plate tectonics. With little or no warning, an earthquake or volcanic eruption can unleash bursts of energy far more powerful than anything we can generate. While we have no control over plate-tectonic processes, we now have the knowledge to learn from them. The more we know about plate tectonics, the better we can appreciate the grandeur and beauty of the land upon which we live, as well as the occasional violent displays of the Earth's awesome power.This booklet gives a brief introduction to the concept of plate tectonics and complements the visual and written information in This Dynamic Planet (see Further reading), a map published in 1994 by the U.S. Geological Survey (USGS) and the Smithsonian Institution. The booklet highlights some of the people and discoveries that advanced the development of the theory and traces its progress since its proposal. Although the general idea of plate tectonics is now widely accepted, many aspects still continue to confound and challenge scientists. The earth-science revolution launched by the theory of plate tectonics is not finished.

Spatial and temporal variation of tectonic uplift in the southeastern Ethiopian Plateau from morphotectonic analysis

NASA Astrophysics Data System (ADS)

Xue, Liang; Alemu, Tadesse; Gani, Nahid D.; Abdelsalam, Mohamed G.

2018-05-01

We use morphotectonic analysis to study the tectonic uplift history of the southeastern Ethiopian Plateau (SEEP). Based on studies conducted on the Northwestern Ethiopian Plateau, steady-state and pulsed tectonic uplift models were proposed to explain the growth of the plateau since 30 Ma. We test these two models for the largely unknown SEEP. We present the first quantitative morphotectonic study of the SEEP. First, in order to infer the spatial distribution of the tectonic uplift rates, we extract geomorphic proxies including normalized steepness index ksn, hypsometric integral HI, and chi integral χ from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation model (DEM). Second, we compare these rates with the thickness of flood basalt that we estimated from geological maps. Third, to constrain the timing of regional tectonic uplift, we develop a knickpoint celerity model. Fourth, we compare our results to those from the Northwestern Ethiopian Plateau to suggest a possible mechanism to explain regional tectonic uplift of the entire Ethiopian Plateau. We find an increase in tectonic uplift rates from the southeastern escarpments of the Afar Depression in the northeast to that of the Main Ethiopian Rift to the southwest. We identify three regional tectonic uplift events at 11.7, 6.5, and 4.5 Ma recorded by the development of regionally distributed knickpoints. This is in good agreement with ages of tectonic uplift events reported from the Northwestern Ethiopian Plateau.

Topographic representation using DEMs and its applications to active tectonics research

NASA Astrophysics Data System (ADS)

Oguchi, T.; Lin, Z.; Hayakawa, Y. S.

2016-12-01

Identifying topographic deformations due to active tectonics has been a principal issue in tectonic geomorphology. It provides useful information such as whether a fault has been active during the recent past. Traditionally, field observations, conventional surveying, and visual interpretation of topographic maps, aerial photos, and satellite images were the main methods for such geomorphological investigations. However, recent studies have been utilizing digital elevation models (DEMs) to visualize and quantitatively analyze landforms. There are many advantages to the use of DEMs for research in active tectonics. For example, unlike aerial photos and satellite images, DEMs show ground conditions without vegetation and man-made objects such as buildings, permitting direct representation of tectonically deformed landforms. Recent developments and advances in airborne LiDAR also allow the fast creation of DEMs even in vegetated areas such as forested lands. In addition, DEMs enable flexible topographic visualization based on various digital cartographic and computer-graphic techniques, facilitating identification of particular landforms such as active faults. Further, recent progress in morphometric analyses using DEMs can be employed to quantitatively represent topographic characteristics, and objectively evaluate tectonic deformation and the properties of related landforms. This paper presents a review of DEM applications in tectonic geomorphology, with attention to historical development, recent advances, and future perspectives. Examples are taken mainly from Japan, a typical tectonically active country. The broader contributions of DEM-based active tectonics research to other fields, such as fluvial geomorphology and geochronology, will also be discussed.

[Study of the health food information for cancer patients on Japanese websites].

PubMed

Kishimoto, Keiko; Yoshino, Chie; Fukushima, Noriko

2010-08-01

The aim of this paper is to evaluate the reliability of websites providing health food information for cancer patients and, to assess the status to get this information online. We used four common Japanese search engines (Yahoo!, Google, goo, and MSN) to look up websites on Dec. 2, 2008. The search keywords were "health food" and "cancer". The websites for the first 100 hits generated by each search engine were screened and extracted by three conditions. We extracted 64 unique websites by the result of retrieval, of which 54 websites had information about health food factors. The two scales were used to evaluate the quality of the content on 54 websites. On the scale of reliability of information on the Web, the average score was 2.69+/-1.70 (maximum 6) and the median was 2.5. The other scale was matter need to check whether listed to use safely this information. On this scale, the average score was 0.72+/-1.22 (maximum 5) and the median was 0. Three engines showed poor correlation between the ranking and the latter score. But several websites on the top indicated 0 score. Fifty-four websites were extracted with one to four engines and the average number of search engines was 1.9. The two scales were positively correlated with the number of search engines, but these correlations were very poor. Ranking high and extraction by multiple search engines were of minor benefit to pick out more reliable information.

Continental tectonics in the aftermath of plate tectonics

NASA Technical Reports Server (NTRS)

Molnar, Peter

1988-01-01

It is shown that the basic tenet of plate tectonics, rigid-body movements of large plates of lithosphere, fails to apply to continental interiors. There, buoyant continental crust can detach from the underlying mantle to form mountain ranges and broad zones of diffuse tectonic activity. The role of crustal blocks and of the detachment of crustal fragments in this process is discussed. Future areas of investigation are addressed.

Enhancing the Human Factors Engineering Role in an Austere Fiscal Environment

NASA Technical Reports Server (NTRS)

Stokes, Jack W.

2003-01-01

An austere fiscal environment in the aerospace community creates pressures to reduce program costs, often minimizing or sometimes even deleting the human interface requirements from the design process. With an assumption that the flight crew can recover real time from a poorly human factored space vehicle design, the classical crew interface requirements have been either not included in the design or not properly funded, though carried as requirements. Cost cuts have also affected quality of retained human factors engineering personnel. In response to this concern, planning is ongoing to correct the acting issues. Herein are techniques for ensuring that human interface requirements are integrated into a flight design, from proposal through verification and launch activation. This includes human factors requirements refinement and consolidation across flight programs; keyword phrases in the proposals; closer ties with systems engineering and other classical disciplines; early planning for crew-interface verification; and an Agency integrated human factors verification program, under the One NASA theme. Importance is given to communication within the aerospace human factors discipline, and utilizing the strengths of all government, industry, and academic human factors organizations in an unified research and engineering approach. A list of recommendations and concerns are provided in closing.

GeoFramework: A Modeling Framework for Solid Earth Geophysics

NASA Astrophysics Data System (ADS)

Gurnis, M.; Aivazis, M.; Tromp, J.; Tan, E.; Thoutireddy, P.; Liu, Q.; Choi, E.; Dicaprio, C.; Chen, M.; Simons, M.; Quenette, S.; Appelbe, B.; Aagaard, B.; Williams, C.; Lavier, L.; Moresi, L.; Law, H.

2003-12-01

As data sets in geophysics become larger and of greater relevance to other earth science disciplines, and as earth science becomes more interdisciplinary in general, modeling tools are being driven in new directions. There is now a greater need to link modeling codes to one another, link modeling codes to multiple datasets, and to make modeling software available to non modeling specialists. Coupled with rapid progress in computer hardware (including the computational speed afforded by massively parallel computers), progress in numerical algorithms, and the introduction of software frameworks, these lofty goals of merging software in geophysics are now possible. The GeoFramework project, a collaboration between computer scientists and geoscientists, is a response to these needs and opportunities. GeoFramework is based on and extends Pyre, a Python-based modeling framework, recently developed to link solid (Lagrangian) and fluid (Eulerian) models, as well as mesh generators, visualization packages, and databases, with one another for engineering applications. The utility and generality of Pyre as a general purpose framework in science is now being recognized. Besides its use in engineering and geophysics, it is also being used in particle physics and astronomy. Geology and geophysics impose their own unique requirements on software frameworks which are not generally available in existing frameworks and so there is a need for research in this area. One of the special requirements is the way Lagrangian and Eulerian codes will need to be linked in time and space within a plate tectonics context. GeoFramework has grown beyond its initial goal of linking a limited number of exiting codes together. The following codes are now being reengineered within the context of Pyre: Tecton, 3-D FE Visco-elastic code for lithospheric relaxation; CitComS, a code for spherical mantle convection; SpecFEM3D, a SEM code for global and regional seismic waves; eqsim, a FE code for dynamic earthquake rupture; SNAC, a developing 3-D coded based on the FLAC method for visco-elastoplastic deformation; SNARK, a 3-D FE-PIC method for viscoplastic deformation; and gPLATES an open source paleogeographic/plate tectonics modeling package. We will demonstrate how codes can be linked with themselves, such as a regional and global model of mantle convection and a visco-elastoplastic representation of the crust within viscous mantle flow. Finally, we will describe how http://GeoFramework.org has become a distribution site for a suite of modeling software in geophysics.

Significant Centers of Tectonic Activity as Identified by Wrinkle Ridges for the Western Hemisphere of Mars

NASA Technical Reports Server (NTRS)

Anderson, R.C.; Haldemann, A. F. C.; Golombek, M. P.; Franklin, B. J.; Dohm, J. M.; Lias, J.

2000-01-01

The western hemisphere region of Mars has been the site of numerous scientific investigations regarding its tectonic evolution. For this region of Mars, the dominant tectonic region is the Tharsis province. Tharsis is characterized by an enormous system of radiating grabens and a circumferential system of wrinkle ridges. Past investigations of grabens associated with Tharsis have identified specific centers of tectonic activity. A recent structural analysis of the western hemisphere region of Mars which includes the Tharsis region, utilized 25,000 structures to determine the history of local and regional centers of tectonic activity based primarily on the spatial and temporal relationships of extensional features. This investigation revealed that Tharsis is more structurally complex (heterogeneous) than has been previously identified: it consists of numerous regional and local centers of tectonic activity (some are more dominant and/or more long lived than others). Here we use the same approach as Anderson et al. to determine whether the centers of tectonic activity that formed the extensional features also contributed to wrinkle ridge (compressional) formation.

Turbiditic systems on passive margins: fifteen years of fruitful industry-academic exchanges.

NASA Astrophysics Data System (ADS)

Guillocheau, F.

2012-04-01

During the last fifteen years, with the oil discovery in deep offshore plays, new tools have been developed that deeply modified our knowledge on sedimentary gravity processes on passive margins: geometry, physical processes, but also the importance of the topography and the quantification of the stratigraphic parameters of control. The major breakthrough was of course the extensive 3D seismic data available around most of the world margins with a focus on gravity-tectonics dominated margins. The first major progress was the characterization of the sinuous channels infilling, their diversity and different models for their origin. This also was a better knowledge of the different types of slopes (graded vs. above-graded) and the extension of the concept of accommodation to deep-water environments (ponded, healed-slope, incised submarine valley and slope accommodation). The second step was the understanding of the synsedimentary deformations for the location and the growth of turbiditic systems on margins dominated by gravity tectonics, with the importance of the sedimentary flux and its variation through time and space. The third step is now the integration of the sedimentary system, from the upstream erosional catchment to the abyssal plain (source to sink approach), with the question of the sediment routing system. During the last 100 Ma, continents experienced major changes of both topography and climate. In the case of Africa, those are (1) the growth of the plateaus (and mainly the South African one) around 90-80 Ma (Late Cretaceous) and 40-20 Ma (Late Eocene-Early Miocene) and (2) a climate evolution from hot humid (50-40 Ma) to hot dry conditions since 20-15 Ma. This evolution changed the topography, the processes of erosion and the volume and nature (weathered vs. non weathered rocks) materials. Those are primary processes for controlling the deposition of turbiditic systems, and then to predict the location of sands. This will be discussed along the Atlantic margin of Africa. Keywords: Turbidite, Passive margins, Topography, Deformation, Source to sink

Cracking mechanism of shale cracks during fracturing

NASA Astrophysics Data System (ADS)

Zhao, X. J.; Zhan, Q.; Fan, H.; Zhao, H. B.; An, F. J.

2018-06-01

In this paper, we set up a model for calculating the shale fracture pressure on the basis of Huang’s model by the theory of elastic-plastic mechanics, rock mechanics and the application of the maximum tensile stress criterion, which takes into account such factors as the crustal stress field, chemical field, temperature field, tectonic stress field, the porosity of shale and seepage of drilling fluid and so on. Combined with the experimental data of field fracturing and the experimental results of three axis compression of shale core with different water contents, the results show that the error between the present study and the measured value is 3.85%, so the present study can provide technical support for drilling engineering.

Tectonic Geomorphology.

ERIC Educational Resources Information Center

Bull, William B.

1984-01-01

Summarizes representative quantitative tectonic-geomorphology studies made during the last century, focusing on fault-bounded mountain-front escarpments, marine terraces, and alluvial geomorphic surfaces (considering stream terraces, piedmont fault scarps, and soils chronosequences). Also suggests where tectonic-geomorphology courses may best fit…

Plate tectonics and planetary habitability: current status and future challenges.

PubMed

Korenaga, Jun

2012-07-01

Plate tectonics is one of the major factors affecting the potential habitability of a terrestrial planet. The physics of plate tectonics is, however, still far from being complete, leading to considerable uncertainty when discussing planetary habitability. Here, I summarize recent developments on the evolution of plate tectonics on Earth, which suggest a radically new view on Earth dynamics: convection in the mantle has been speeding up despite its secular cooling, and the operation of plate tectonics has been facilitated throughout Earth's history by the gradual subduction of water into an initially dry mantle. The role of plate tectonics in planetary habitability through its influence on atmospheric evolution is still difficult to quantify, and, to this end, it will be vital to better understand a coupled core-mantle-atmosphere system in the context of solar system evolution. © 2012 New York Academy of Sciences.

Easy handling of tectonic data: the programs TectonicVB for Mac and TectonicsFP for Windows™

NASA Astrophysics Data System (ADS)

Ortner, Hugo; Reiter, Franz; Acs, Peter

2002-12-01

TectonicVB for Macintosh and TectonicsFP for Windows TM operating systems are two menu-driven computer programs which allow the shared use of data on these environments. The programs can produce stereographic plots of orientation data (great circles, poles, lineations). Frequently used statistical procedures like calculation of eigenvalues and eigenvectors, calculation of mean vector with concentration parameters and confidence cone can be easily performed. Fault data can be plotted in stereographic projection (Angelier and Hoeppener plots). Sorting of datasets into homogeneous subsets and rotation of tectonic data can be performed in interactive two-diagram windows. The paleostress tensor can be calculated from fault data sets using graphical (calculation of kinematic axes and right dihedra method) or mathematical methods (direct inversion or numerical dynamical analysis). The calculations can be checked in dimensionless Mohr diagrams and fluctuation histograms.

Cenozoic tectonic reorganizations of the Death Valley region, southeast California and southwest Nevada

USGS Publications Warehouse

Fridrich, Christopher J.; Thompson, Ren A.

2011-01-01

The Death Valley region, of southeast California and southwest Nevada, is distinct relative to adjacent regions in its structural style and resulting topography, as well as in the timing of basin-range extension. Cenozoic basin-fill strata, ranging in age from greater than or equal to 40 to approximately 2 million years are common within mountain-range uplifts in this region. The tectonic fragmentation and local uplift of these abandoned basin-fills indicate a multistage history of basin-range tectonism. Additionally, the oldest of these strata record an earlier, pre-basin-range interval of weak extension that formed broad shallow basins that trapped sediments, without forming basin-range topography. The Cenozoic basin-fill strata record distinct stratigraphic breaks that regionally cluster into tight age ranges, constrained by well-dated interbedded volcanic units. Many of these stratigraphic breaks are long recognized formation boundaries. Most are angular unconformities that coincide with abrupt changes in depositional environment. Deposits that bound these unconformities indicate they are weakly diachronous; they span about 1 to 2 million years and generally decrease in age to the west within individual basins and regionally, across basin boundaries. Across these unconformities, major changes are found in the distribution and provenance of basin-fill strata, and in patterns of internal facies. These features indicate rapid, regionally coordinated changes in strain patterns defined by major active basin-bounding faults, coincident with step-wise migrations of the belt of active basin-range tectonism. The regionally correlative unconformities thus record short intervals of radical tectonic change, here termed "tectonic reorganizations." The intervening, longer (about 3- to 5-million-year) interval of gradual, monotonic evolution in the locus and style of tectonism are called "tectonic stages." The belt of active tectonism in the Death Valley region has abruptly stepped westward during three successive tectonic reorganizations that intervened between four stages of basin-range tectonism, the youngest of which is ongoing. These three tectonic reorganizations also intervened between four stages of volcanic activity, each of which has been distinct in the compositions of magmas erupted, in eruption rates, and in the locus of volcanic activity—which has stepped progressively westward, in close coordination with the step-wise migrations in the locus of basin-range extension. The timing of the Cenozoic tectonic reorganizations in the Death Valley region correlates closely with the documented timing of episodic reorganizations of the boundary between the Pacific and North American plates, to the west and southwest. This supports models that explain the widely distributed transtensional tectonism in southwestern North America since approximately 40 million years ago as resulting from traction imposed by the adjacent, divergent Pacific plate.

Quantitative analysis of the tectonic subsidence in the Potiguar Basin (NE Brazil)

NASA Astrophysics Data System (ADS)

Lopes, Juliana A. G.; de Castro, David L.; Bertotti, Giovanni

2018-06-01

The Potiguar Basin, located in the Brazilian Equatorial Margin, evolved from a complex rifting process implemented during the Atlantic Ocean opening in the Jurassic/Cretaceous. Different driving mechanisms were responsible for the onset of an aborted onshore rift and an offshore rift that initiated crustal rupture and the formation of a continental transform margin. Therefore, we applied the backstripping method to quantify the tectonic subsidence during the rift and post-rift phases of Potiguar Basin formation and to analyze the spatial variation of subsidence during the two successive and distinct tectonic events responsible for the basin evolution. The parameters required to apply this methodology were extracted from 2D seismic lines and exploratory well data. The tectonic subsidence curves present periods with moderate subsidence rates (up to 300 m/My), which correspond to the evolution of the onshore Potiguar Rift (∼141 to 128 Ma). From 128-118 Ma, the tectonic subsidence curves show no subsidence in the onshore Potiguar Basin, whereas subsidence occurred at high rates (over 300 m/My) in the offshore rift. The post-rift phase began ca. 118 Ma (Aptian), when the tectonic subsidence drastically slowed to less than 35 m/My, probably related to thermal relaxation. The tectonic subsidence rates in the various sectors of the Potiguar Rift, during the different rift phases, indicate that more intense faulting occurred in the southern portion of the onshore rift, along the main border faults, and in the southeastern portion of the offshore rift. During the post-rift phase, the tectonic subsidence rates increased from the onshore portion towards the offshore portion until the continental slope. The highest rates of post-rift subsidence (up to 35 m/My) are concentrated in the central region of the offshore portion and may be related to lithospheric processes related to the continental crust rupture and oceanic seafloor spreading. The variation in subsidence rates and the pattern of tectonic subsidence curves allowed us to interpret the tectonic signature recorded by the sedimentary sequences of the Potiguar Basin during its evolution. In the onshore rift area, the tectonic subsidence curves presented subsidence rates up to 300 m/My during a long-term rift phase (13 Ma), which confirmed that this portion had an extensional tectonic regime. In the offshore rift, the curves presented high subsidence rates of over 300 m/My in a shorter period (5-10 My), typical of basins formed in a transtensional tectonic regime.

Development of the Plate Tectonics and Seismology markup languages with XML

NASA Astrophysics Data System (ADS)

Babaie, H.; Babaei, A.

2003-04-01

The Extensible Markup Language (XML) and its specifications such as the XSD Schema, allow geologists to design discipline-specific vocabularies such as Seismology Markup Language (SeismML) or Plate Tectonics Markup Language (TectML). These languages make it possible to store and interchange structured geological information over the Web. Development of a geological markup language requires mapping geological concepts, such as "Earthquake" or "Plate" into a UML object model, applying a modeling and design environment. We have selected four inter-related geological concepts: earthquake, fault, plate, and orogeny, and developed four XML Schema Definitions (XSD), that define the relationships, cardinalities, hierarchies, and semantics of these concepts. In such a geological concept model, the UML object "Earthquake" is related to one or more "Wave" objects, each arriving to a seismic station at a specific "DateTime", and relating to a specific "Epicenter" object that lies at a unique "Location". The "Earthquake" object occurs along a "Segment" of a "Fault" object, which is related to a specific "Plate" object. The "Fault" has its own associations with such things as "Bend", "Step", and "Segment", and could be of any kind (e.g., "Thrust", "Transform'). The "Plate" is related to many other objects such as "MOR", "Subduction", and "Forearc", and is associated with an "Orogeny" object that relates to "Deformation" and "Strain" and several other objects. These UML objects were mapped into XML Metadata Interchange (XMI) formats, which were then converted into four XSD Schemas. The schemas were used to create and validate the XML instance documents, and to create a relational database hosting the plate tectonics and seismological data in the Microsoft Access format. The SeismML and TectML allow seismologists and structural geologists, among others, to submit and retrieve structured geological data on the Internet. A seismologist, for example, can submit peer-reviewed and reliable data about a specific earthquake to a Java Server Page on our web site hosting the XML application. Other geologists can readily retrieve the submitted data, saved in files or special tables of the designed database, through a search engine designed with J2EE (JSP, servlet, Java Bean) and XML specifications such as XPath, XPointer, and XSLT. When extended to include all the important concepts of seismology and plate tectonics, the two markup languages will make global interchange of geological data a reality.

Accretionary history of the Altai-Mongolian terrane: perspectives from granitic zircon U-Pb and Hf-isotope data

NASA Astrophysics Data System (ADS)

Cai, Keda; Sun, Min; Xiao, Wenjiao

2014-05-01

The Central Asian Orogenic Belt (CAOB) consists of many tectonic terranes with distinct origin and complicated evolutionary history. Understanding of individual block is crucial to reconstruct the geodynamic history of the gigantic accetionary collage. This study presents zircon U-Pb ages and Hf isotopes for the granitoid rocks in the Russian Altai mountain range (including Gorny Altai, Altai-Mongolian terrane and CTUS suture zone between them), in order to clarify the timing of granitic magmatism, source nature, continental crustal growth and tectonic evolution. Our dating results suggest that granitic magmatism of the Russian Altai mountain range occurred in three major episodes including 445~429 Ma, 410~360 Ma and ~241 Ma. Most of the zircons within the Paleozoic granitoids present comparable positive ɛHf(t) values and Neoproterozoic crustal model ages, which favor the interpretation that the juvenile crustal materials produced in the early stage of CAOB were probably dominant sources for the Paleozoic magmatism in the region. The inference is also supported by widespread occurrence of short-lived juvenile materials including ophiolites, seamount relics and arc assemblages in the north CAOB. Consequently, the Paleozoic massive granitic rocks maybe not represent continental crustal growth at the time when they were emplaced, but rather record reworking of relatively juvenile Proterozoic crustal rocks although mantle-derived mafic magma was possibly involved to sever as heat engine during granitic magma generation. The Early Triassic granitic intrusion may be product in an intra-plate environment, as the case of same type rocks in the adjacent areas. The positive ɛHf(t) values (1.81~7.47) and corresponding Hf model ages (0.80~1.16 Ga) together with evidence of petrology are consistent with the interpretation that the parental magma of the Triassic granitic intrusion was produced from enriched mantle-derived sources under an usually high temperature condition which is likely due to basaltic magma that underplated the lower crust. Our data combined with evidence of the regional geology enable us to conclude that the Gorny Altai and Altai-Mongolian terranes possibly have similar tectonic natures, but represent two separate accretionary systems before Devonian collision. The accretion and amalgamation processes resulted in the Paleozoic granitoid magmatism and caused the two terranes to merge as a composite tectonic domain at the Siberian continental margin.

The effects of internal heating and large scale climate variations on tectonic bi-stability in terrestrial planets

NASA Astrophysics Data System (ADS)

Weller, M. B.; Lenardic, A.; O'Neill, C.

2015-06-01

We use 3D mantle convection and planetary tectonics models to explore the links between tectonic regimes and the level of internal heating within the mantle of a planet (a proxy for thermal age), planetary surface temperature, and lithosphere strength. At both high and low values of internal heating, for moderate to high lithospheric yield strength, hot and cold stagnant-lid (single plate planet) states prevail. For intermediate values of internal heating, multiple stable tectonic states can exist. In these regions of parameter space, the specific evolutionary path of the system has a dominant role in determining its tectonic state. For low to moderate lithospheric yield strength, mobile-lid behavior (a plate tectonic-like mode of convection) is attainable for high degrees of internal heating (i.e., early in a planet's thermal evolution). However, this state is sensitive to climate driven changes in surface temperatures. Relatively small increases in surface temperature can be sufficient to usher in a transition from a mobile- to a stagnant-lid regime. Once a stagnant-lid mode is initiated, a return to mobile-lid is not attainable by a reduction of surface temperatures alone. For lower levels of internal heating, the tectonic regime becomes less sensitive to surface temperature changes. Collectively our results indicate that terrestrial planets can alternate between multiple tectonic states over giga-year timescales. Within parameter space regions that allow for bi-stable behavior, any model-based prediction as to the current mode of tectonics is inherently non-unique in the absence of constraints on the geologic and climatic histories of a planet.

Tectonic and metallogenic model for northeast Asia

USGS Publications Warehouse

Parfenov, Leonid M.; Nokleberg, Warren J.; Berzin, Nikolai A.; Badarch, Gombosuren; Dril, Sergy I.; Gerel, Ochir; Goryachev, Nikolai A.; Khanchuk, Alexander I.; Kuz'min, Mikhail I.; Prokopiev, Andrei V.; Ratkin, Vladimir V.; Rodionov, Sergey M.; Scotese, Christopher R.; Shpikerman, Vladimir I.; Timofeev, Vladimir F.; Tomurtogoo, Onongin; Yan, Hongquan; Nokleberg, Warren J.

2011-01-01

This document describes the digital files in this report that contains a tectonic and metallogenic model for Northeast Asia. The report also contains background materials. This tectonic and metallogenic model and other materials on this report are derived from (1) an extensive USGS Professional Paper, 1765, on the metallogenesis and tectonics of Northeast Asia that is available on the Internet at http://pubs.usgs.gov/pp/1765/; and (2) the Russian Far East parts of an extensive USGS Professional Paper, 1697, on the metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera that is available on the Internet at http://pubs.usgs.gov/pp/pp1697/. The major purpose of the tectonic and metallogenic model is to provide, in movie format, a colorful summary of the complex geology, tectonics, and metallogenesis of the region. To accomplish this goal four steps were taken: (1) 13 time-stage diagrams, from the late Neoproterozoic (850 Ma) through the present (0 Ma), were adapted, generalized, and transformed into color static time-stage diagrams; (2) the 13 time-stage diagrams were placed in a computer morphing program to produce the model; (3) the model was examined and each diagram was successively adapted to preceding and subsequent diagrams to match the size and surface expression of major geologic units; and (4) the final version of the model was produced in successive iterations of steps 2 and 3. The tectonic and metallogenic model and associated materials in this report are derived from a project on the major mineral deposits, metallogenesis, and tectonics of the Northeast Asia and from a preceding project on the metallogenesis and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera. Both projects provide critical information on bedrock geology and geophysics, tectonics, major metalliferous mineral resources, metallogenic patterns, and crustal origin and evolution of mineralizing systems for this region. The major scientific goals and benefits of the projects are to: (1) provide a comprehensive international data base on the mineral resources of the region that is the first extensive knowledge available in English; (2) provide major new interpretations of the origin and crustal evolution of mineralizing systems and their host rocks, thereby enabling enhanced, broad-scale tectonic reconstructions and interpretations; and (3) promote trade and scientific and technical exchanges between North America and eastern Asia.

Paleomagnetism and tectonics of the Jura arcuate mountain belt in France and Switzerland

NASA Astrophysics Data System (ADS)

Gehring, Andreas U.; Keller, Peter; Heller, Friedrich

1991-02-01

Goethite and hematite in ferriferous oolitic beds of Callovian age from the Jura mountains (Switzerland, France) carry either pre- and/or post-tectonic magnetization. The frequent pre-tectonic origin of goethite magnetization indicates a temperature range during formation of the arcuate Jura mountain belt below the goethite Néel temperature of about 100°C. The scatter of the pre-tectonic paleomagnetic directions ( D = 11.5° E, I = 55.5°; α95 = 4.7) which reside both in goethite and hematite, provides strong evidence that the arcuate mountain belt was shaped without significant rotation. The paleomagnetic results support tectonic thin-skinned models for the formation of the Jura mountain belt.

Geomorphology, tectonics, and exploration

NASA Technical Reports Server (NTRS)

Sabins, F. F., Jr.

1985-01-01

Explorationists interpret satellite images for tectonic features and patterns that may be clues to mineral and energy deposits. The tectonic features of interest range in scale from regional (sedimentary basins, fold belts) to local (faults, fractures) and are generally expressed as geomorphic features in remote sensing images. Explorationists typically employ classic concepts of geomorphology and landform analysis for their interpretations, which leads to the question - Are there new and evolving concepts in geomorphology that may be applicable to tectonic analyses of images?

A Pn Spreading Model Constrained with Observed Amplitudes in Asia

DTIC Science & Technology

2011-09-01

and stations, from which we collected my data. According to Patton (1980), the “ tectonic ” province was defined as an area with its crustal thickness...and the definition of the “ tectonic ” province as a tectonically active region with similar crustal and upper-mantle structure in most parts of the...North Australian Craton: Influence of crustal velocity gradients, Bull. Seismol. Soc. Am. 81: 592–610. Brune, J. N. (1970). Tectonic stress and the

Paleogeographic atlas project-Mesozoic-Cenozoic tectonic map of the world

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rowley, D.B.; Ziegler, A.M.; Hulver, M.

1985-01-01

A Mesozoic-Cenozoic tectonic map of the world has been compiled in order to provide the basis for detailed paleogeographic, first-order palin-spastic and paleo-tectonic reconstructions. The map is plotted from a digital database on two polar stereographic projections that depict both time and type of tectonic activity. Time of activity is shown using six colors, with each color representing approximately 40 m.y. intervals. The time divisions correspond with, and are defined on the basis of times of major changes in plate motions. Tectonic activity is divided into 7 major types: (1) Platformal regions unaffected by major tectonism; (2) Region as underlainmore » by oceanic lithosphere; (3) Regions affected by extensional tectonism-characterized by thinning and stretching of the crust, including Atlantic-type margins, Basin and Range, back-arc and pull-apart basin development; (4) Regions of crustal shortening and thickening, as in collisional orogens and Andean-type foreland-fold systems; (5) Strike-slip systems associated with little or no change in crustal thickness; (6) Subduction accretion prisms, associated with tectonic outbuilding of continental crust, and marking sutures within continents; and (7) Large scale oceanic volcanic/magmatic arcs and plateaus characterized by increased crustal thickness and buoyancy of the lithosphere. The map provides a basis for understanding the assembly of Asia, the Circum-Pacific, and the disaggregation of Pangea.« less

Searching for Hysteresis in Models of Mantle Convection with Grain-Damage

NASA Astrophysics Data System (ADS)

Lamichhane, R.; Foley, B. J.

2017-12-01

The mode of surface tectonics on terrestrial planets is determined by whether mantle convective forces are capable of forming weak zones of localized deformation in the lithosphere, which act as plate boundaries. If plate boundaries can form then a plate tectonic mode develops, and if not convection will be in the stagnant lid regime. Episodic subduction or sluggish lid convection are also possible in between the nominal plate tectonic and stagnant lid regimes. Plate boundary formation is largely a function of the state of the mantle, e.g. mantle temperature or surface temperature, and how these conditions influence both mantle convection and the mantle rheology's propensity for forming weak, localized plate boundaries. However, a planet's tectonic mode also influences whether plate boundaries can form, as the driving forces for plate boundary formation (e.g. stress and viscous dissipation) are different in a plate tectonic versus stagnant lid regime. As a result, tectonic mode can display hysteresis, where convection under otherwise identical conditions can reach different final states as a result of the initial regime of convection. Previous work has explored this effect in pseudoplastic models, finding that it is more difficult to initiate plate tectonics starting from a stagnant lid state than it is to sustain plate tectonics when already in a mobile lid regime, because convective stresses in the lithosphere are lower in a stagnant lid regime than in a plate tectonic regime. However, whether and to what extent such hysteresis is displayed when alternative rheological models for lithospheric shear localization are used is unknown. In particular, grainsize reduction is commonly hypothesized to be a primary cause of shear localization and plate boundary formation. We use new models of mantle convection with grain-size evolution to determine how the initial mode of surface tectonics influences the final convective regime reached when convection reaches statistical steady-state. Scaling analysis is performed to quantify how subduction initiation from a stagnant lid differs from sustaining subduction in a mobile lid. The implications of our results for the evolution of the mode of surface tectonics on terrestrial planets will also be discussed.

Computer-based self-organized tectonic zoning: a tentative pattern recognition for Iran

NASA Astrophysics Data System (ADS)

Zamani, Ahmad; Hashemi, Naser

2004-08-01

Conventional methods of tectonic zoning are frequently characterized by two deficiencies. The first one is the large uncertainty involved in tectonic zoning based on non-quantitative and subjective analysis. Failure to interpret accurately a large amount of data "by eye" is the second. In order to alleviate each of these deficiencies, the multivariate statistical method of cluster analysis has been utilized to seek and separate zones with similar tectonic pattern and construct automated self-organized multivariate tectonic zoning maps. This analytical method of tectonic regionalization is particularly useful for showing trends in tectonic evolution of a region that could not be discovered by any other means. To illustrate, this method has been applied for producing a general-purpose numerical tectonic zoning map of Iran. While there are some similarities between the self-organized multivariate numerical maps and the conventional maps, the cluster solution maps reveal some remarkable features that cannot be observed on the current tectonic maps. The following specific examples need to be noted: (1) The much disputed extent and rigidity of the Lut Rigid Block, described as the microplate of east Iran, is clearly revealed on the self-organized numerical maps. (2) The cluster solution maps reveal a striking similarity between this microplate and the northern Central Iran—including the Great Kavir region. (3) Contrary to the conventional map, the cluster solution maps make a clear distinction between the East Iranian Ranges and the Makran Mountains. (4) Moreover, an interesting similarity between the Azarbaijan region in the northwest and the Makran Mountains in the southeast and between the Kopet Dagh Ranges in the northeast and the Zagros Folded Belt in the southwest of Iran are revealed in the clustering process. This new approach to tectonic zoning is a starting point and is expected to be improved and refined by collection of new data. The method is also a useful tool in studying neotectonics, seismotectonics, seismic zoning, and hazard estimation of the seismogenic regions.

A New Framework For The Evolution of Terrestrial Planets: Bi-stability, Stochastic Effects, and the Non-Uniqueness of Tectonic States

NASA Astrophysics Data System (ADS)

Weller, M. B.; Lenardic, A.

2017-12-01

Of all the Solar System bodies, the Earth is the only one for which significant observation and constraints are accessible such that they can be used to discriminate between competing models of Earth's tectonic evolution. Therefore, it is a natural tendency to use these observations to inform more general models of planetary evolution. Yet, our understating of Earth's evolution is far from complete. Geodynamic and geochemical evidence suggests that plate tectonics may not have operated on the early Earth, with both the timing of its onset and the length of its activity far from certain. In recent years, the potential of tectonic bi-stability (multiple stable, energetically allowed solutions) has been shown to be dynamically viable, both from analytical analysis and through numeric experiments in two and three dimensions. The indication is that multiple tectonic modes may operate on a single planetary body at different times within its temporal evolution. Further, there exists the potential that feedback mechanisms between the internal dynamics and surface processes (e.g., surface temperature changes driven by long term climate evolution), acting at different thermal evolution times, can cause terrestrial worlds to alternate between multiple tectonic states over giga-year timescales. Implied here is that terrestrial planets have the potential to migrate through tectonic regimes at similar `thermal evolutionary times' - points were planets have a similar bulk mantle temperature and energies -, but at very different `temporal times' - time since planetary formation. It can then be shown that identical planets at similar stages of their evolution may exhibit different tectonic regimes due to random fluctuations. A new framework of planetary evolution that moves toward probabilistic arguments based on general physical principals, as opposed to particular rheologies, and incorporates the potential of tectonic regime transitions and multiple tectonics states being viable at equivalent physical and chemical conditions, will be discussed.

Dynamic computer model for the metallogenesis and tectonics of the Circum-North Pacific

USGS Publications Warehouse

Scotese, Christopher R.; Nokleberg, Warren J.; Monger, James W.H.; Norton, Ian O.; Parfenov, Leonid M.; Khanchuk, Alexander I.; Bundtzen, Thomas K.; Dawson, Kenneth M.; Eremin, Roman A.; Frolov, Yuri F.; Fujita, Kazuya; Goryachev, Nikolai A.; Pozdeev, Anany I.; Ratkin, Vladimir V.; Rodinov, Sergey M.; Rozenblum, Ilya S.; Scholl, David W.; Shpikerman, Vladimir I.; Sidorov, Anatoly A.; Stone, David B.

2001-01-01

The digital files on this report consist of a dynamic computer model of the metallogenesis and tectonics of the Circum-North Pacific, and background articles, figures, and maps. The tectonic part of the dynamic computer model is derived from a major analysis of the tectonic evolution of the Circum-North Pacific which is also contained in directory tectevol. The dynamic computer model and associated materials on this CD-ROM are part of a project on the major mineral deposits, metallogenesis, and tectonics of the Russian Far East, Alaska, and the Canadian Cordillera. The project provides critical information on bedrock geology and geophysics, tectonics, major metalliferous mineral resources, metallogenic patterns, and crustal origin and evolution of mineralizing systems for this region. The major scientific goals and benefits of the project are to: (1) provide a comprehensive international data base on the mineral resources of the region that is the first, extensive knowledge available in English; (2) provide major new interpretations of the origin and crustal evolution of mineralizing systems and their host rocks, thereby enabling enhanced, broad-scale tectonic reconstructions and interpretations; and (3) promote trade and scientific and technical exchanges between North America and Eastern Asia.

Rapid biological speciation driven by tectonic evolution in New Zealand

NASA Astrophysics Data System (ADS)

Craw, Dave; Upton, Phaedra; Burridge, Christopher P.; Wallis, Graham P.; Waters, Jonathan M.

2016-02-01

Collisions between tectonic plates lead to the rise of new mountain ranges that can separate biological populations and ultimately result in new species. However, the identification of links between tectonic mountain-building and biological speciation is confounded by environmental and ecological factors. Thus, there are surprisingly few well-documented examples of direct tectonic controls on terrestrial biological speciation. Here we present examples from New Zealand, where the rapid evolution of 18 species of freshwater fishes has resulted from parallel tectonic landscape evolution. We use numerical models to reconstruct changes in the deep crustal structure and surface drainage catchments of the southern island of New Zealand over the past 25 million years. We show that the island and mountain topography evolved in six principal tectonic zones, which have distinct drainage catchments that separated fish populations. We use new and existing phylogenetic analyses of freshwater fish populations, based on over 1,000 specimens from more than 400 localities, to show that fish genomes can retain evidence of this tectonic landscape development, with a clear correlation between geologic age and extent of DNA sequence divergence. We conclude that landscape evolution has controlled on-going biological diversification over the past 25 million years.

Early Earth plume-lid tectonics: A high-resolution 3D numerical modelling approach

NASA Astrophysics Data System (ADS)

Fischer, R.; Gerya, T.

2016-10-01

Geological-geochemical evidence point towards higher mantle potential temperature and a different type of tectonics (global plume-lid tectonics) in the early Earth (>3.2 Ga) compared to the present day (global plate tectonics). In order to investigate tectono-magmatic processes associated with plume-lid tectonics and crustal growth under hotter mantle temperature conditions, we conduct a series of 3D high-resolution magmatic-thermomechanical models with the finite-difference code I3ELVIS. No external plate tectonic forces are applied to isolate 3D effects of various plume-lithosphere and crust-mantle interactions. Results of the numerical experiments show two distinct phases in coupled crust-mantle evolution: (1) a longer (80-100 Myr) and relatively quiet 'growth phase' which is marked by growth of crust and lithosphere, followed by (2) a short (∼20 Myr) and catastrophic 'removal phase', where unstable parts of the crust and mantle lithosphere are removed by eclogitic dripping and later delamination. This modelling suggests that the early Earth plume-lid tectonic regime followed a pattern of episodic growth and removal also called episodic overturn with a periodicity of ∼100 Myr.

Landslide Hazard Zonation and Risk Assessment of Ramganga Basin in Garhwal Himalaya

NASA Astrophysics Data System (ADS)

Wasini Pandey, Bindhy; Roy, Nikhil

2016-04-01

The Himalaya being unique in its physiographic, tectonic and climatic characteristics coupled with many natural and man-made factors is inherently prone to landslides. These landslides lead to mass loss of property and lives every year in Himalayas. Hence, Landslide Hazard Zonation is important to take quick and safe mitigation measures and make strategic planning for future development. The present study tries to explore the causes of landslides in Ramganga Basin in Garhwal Himalaya, which has an established history and inherent susceptibility to massive landslides has been chosen for landslide hazard zonation and risk assessment. The satellite imageries of LANDSAT, IRS P6, ASTER along with Survey of India (SOI) topographical sheets formed the basis for deriving baseline information on various parameters like slope, aspect, relative relief, drainage density, geology/lithology and land use/land cover. The weighted parametric method will be used to determine the degree of susceptibility to landslides. Finally, a risk map will be prepared from the landslide probability values, which will be classified into no risk, very low to moderate, high, and very high to severe landslide hazard risk zones. Keywords: Landslides, Hazard Zonation, Risk Assessment

Socio-Ecological Changes and Human Mobility in Landslide Zones of Chamoli District of Uttarakhand

NASA Astrophysics Data System (ADS)

Singh, Desh Deepak

2017-04-01

Disaster displacement represents one of the biggest humanitarian challenges of the 21st century. Between 2008 and 2014, 184.6 million people were forced from their homes due to different natural disasters, with 19.3 million newly displaced in 2014, according to the latest available data from the Internal Displacement Monitoring Centre (IDMC). In Uttarakhand state in India, hill slopes are known for their instability as they are ecologically fragile, tectonically and seismically active, and geologically sensitive that makes it prone to landslide hazards. Coupled to this, the rapid expansion of human societies often forces people to occupy highly dynamic and unstable environments. Repeated instances of landslide in highly populated areas have now forced many people to out migrate from vulnerable and high risk areas of Uttarakhand. The present study overlays the maps of geology, vegetation, route network, and settlement of Chamoli district of Uttarakhand to find out through overlay analysis, the landslide risk zonation map of Chamoli. Further, through primary survey in the high risk zones, the migration pattern and migration intensity has been analysed and a model for determining long term trend of migration in ecologically changing location has been developed. Keywords: Landslides, Uttarakhand, Migration, Risk Zonation Mapping

Landscape self organisation: Modelling Sediment trains

NASA Astrophysics Data System (ADS)

Schoorl, J. M.; Temme, A. J. A. M.; Veldkamp, A.

2012-04-01

Rivers tend to develop towards an equilibrium length profile, independently of exogenous factors. In general, although still under debate, this so-called self-organisation is assumed to be caused by simple feedbacks between sedimentation and erosion. Erosion correlates positively with gradient and discharge and sedimentation negatively. With the LAPSUS model, which was run for the catchment of the Sabinal, a small river in the South of Spain, this interplay of erosion and sedimentation results in sediment pulses (sequences of incision and sedimentation through time). These pulses are visualised in a short movie ( see http://www.youtube.com/watch?v=V5LDUMvYZxU). In this case the LAPSUS model run did not take climate, base level nor tectonics into account. Therefore, these pulses can be considered independent of them. Furthermore, different scenarios show that the existence of the pulses is independent of precipitation, erodibility and sedimentation rate, although they control the number and shape of the pulses. A fieldwork check showed the plausibility of the occurrence of these sediment pulses. We conclude that the pulses as modelled with LAPSUS are indeed the consequence of the feedbacks between erosion and sedimentation and are not depending on exogenous factors. Keywords: Landscape self-organisation, Erosion, Deposition, LAPSUS, Modelling

Geologic and Seismologic Investigation

DTIC Science & Technology

1988-12-01

Descriptions, Hidden and Buchanan Dams 4 1.6.1 Hidden Dam 4 1.6.2 Buchanan Dam 5 2 TECTONIC SETTING 2.1 General 7 2.2 Cretaceous-Cenozoic Tectonic ...Activity 7 2.2.1 Cretaceous-Paleogene 8 2.2.2 Neogene 9 2.2.3 Late Cenozoic Tectonic Model 9 3 REGIONAL GEOLOGY 3.1 General 11 3.2 Geologic Units 11...detected by the imagery analysis which indicates there has been no tectonic movement from about 100,000 to 400,000 years ago to the present. The field

Tectonics and volcanism of Eastern Aphrodite Terra, Venus - No subduction, no spreading

NASA Technical Reports Server (NTRS)

Hansen, Vicki L.; Phillips, Roger J.

1993-01-01

Eastern Aphrodite Terra, a deformed region with high topographic relief on Venus, has been interpreted as analogous to a terrestrial extensional or convergent plate boundary. However, analysis of geological and structural relations indicates that the tectonics of eastern Aphrodite Terra is dominated by blistering of the crust by magma diapirs. The findings imply that, within this region, vertical tectonism dominates over horizontal tectonism and, consequently, that this region is neither a divergent nor a convergent plate boundary.

Venus tectonics - An overview of Magellan observations

NASA Technical Reports Server (NTRS)

Solomon, Sean C.; Smrekar, Suzanne E.; Bindschadler, Duane L.; Grimm, Robert E.; Kaula, William M.; Mcgill, George E.; Phillips, Roger J.; Saunders, R. S.; Schubert, Gerald; Squyres, Steven W.

1992-01-01

Magellan observations of the tectonic characteristics of highland regions on Venus are discussed with reference to competing theories for highland formation and evolution. Complex rigid terrain, or tessera, and the extent to which these elevated blocks of intensely deformed crust may be genetically related to highlands are then considered. Further, the tectonics of plains and lowland regions are examined, including deformation belts and coronae, and possible relations between such features and mantle dynamics. Implications of these observations for the global tectonics of Venus are discussed.

Geohistory analysis of the Santa Maria basin, California, and its relationship to tectonic evolution of the continental margin

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCrory, P.A.; Arends, R.G.; Ingle, J.C. Jr.

1991-02-01

The Santa Maria basin of central California is a geologically complex area located along the tectonically active California continental margin. The record of Cenozoic tectonism preserved in Santa Maria strata provides an opportunity to compare the evolution of the region with plate tectonic models for Cenozoic interactions along the margin. Geohistory analysis of Neogene Santa Maria basin strata provides important constraints for hypotheses of the tectonic evolution of the central California margin during its transition from a convergent to a transform plate boundary. Preliminary analyses suggest that the tectonic evolution of the Santa Maria area was dominated by coupling betweenmore » adjacent oceanic plates and the continental margin. This coupling is reflected in the timing of major hiatuses within the basin sedimentary sequence and margin subsidence and uplift which occurred during periods of tectonic plate adjustment. Stratigraphic evidence indicates that the Santa Maria basin originated on the continental shelf in early Miocene time. A component of margin subsidence is postulated to have been caused by cessation of spreading on adjacent offshore microplates approximately 19-18 ma. A sharp reduction in rate of tectonic subsidence in middle Miocene time, observed in the Santa Maria basin both onshore and offshore, was coeval with rotation of crustal blocks as major shearing shifts shoreward. Tectonic uplift of two eastern sites, offshore Point Arguello and near Point Sal, in the late Miocene may have been related to a change to transpressional motion between the Pacific and North American plates, as well as to rotation of the western Transverse Ranges in a restraining geometry.« less

Initiation of plate tectonics from post-magma ocean thermochemical convection

NASA Astrophysics Data System (ADS)

Foley, Bradford J.; Bercovici, David; Elkins-Tanton, Linda T.

2014-11-01

Leading theories for the presence of plate tectonics on Earth typically appeal to the role of present day conditions in promoting rheological weakening of the lithosphere. However, it is unknown whether the conditions of the early Earth were favorable for plate tectonics, or any form of subduction, and thus, how subduction begins is unclear. Using physical models based on grain-damage, a grainsize-feedback mechanism capable of producing plate-like mantle convection, we demonstrate that subduction was possible on the Hadean Earth (hereafter referred to as proto-subduction or proto-plate tectonics), that proto-subduction differed from modern day plate tectonics, and that it could initiate rapidly. Scaling laws for convection with grain-damage show that though either higher mantle temperatures or higher surface temperatures lead to slower plates, proto-subduction, with plate speeds of ≈1.75 cm/yr, can still be maintained in the Hadean, even with a CO2 rich primordial atmosphere. Furthermore, when the mantle potential temperature is high (e.g., above ≈2000 K), the mode of subduction switches to a "sluggish subduction" style, where downwellings are drip like and plate boundaries are diffuse. Finally, numerical models of post-magma ocean mantle convection demonstrate that proto-plate tectonics likely initiates within ˜100 Myr of magma ocean solidification, consistent with evidence from Hadean zircons. After the initiation of proto-subduction, non-plate-tectonic "sluggish subduction" prevails, giving way to modern style plate tectonics as both the mantle interior and climate cool. Hadean proto-subduction may hasten the onset of modern plate tectonics by drawing excess CO2 out of the atmosphere and cooling the climate.

Hierarchical modeling of professional skills in the field of castings manufacture engineering

NASA Astrophysics Data System (ADS)

Samuilă, V.; Soporan, V. F.; Conțiu, G.; Pădurețu, S.; Lehene, T. R.; Vescan, M. M.

2017-06-01

The paper presents a method of hierarchizing professional skills in the manufacturing of molded parts (castings) by using and adapting the FAHP algorithm (Fuzzy Analitical Hierarchy Process). Assessments are made regarding the peculiarities of the professional training process, specifying the activities to be carried out and the competences necessary for their development. The contribution of the design of the method extends to the design of the hierarchy system architecture, the linguistic determination of the importance of each characteristic, the construction of the fuzzy ordering matrices for each stage of the process, the determination of the share of the characteristics for each hierarchy step and establishing the hierarchy of the characteristics taking into account the influences of the others, grouped at the level of the steps and within the global matrix. The research carried out represents the support for generating an instrument of hierarchy of professional competencies that can be used in various professional and institutional contexts. Case study on the hierarchy of professional skills in the manufacturing of molded parts engineering. Keywords: Materials engineering, castings manufacture professional skills, hierarchy, AHP method, standard occupational curriculum.

Hyperthermal Environments Simulator for Nuclear Rocket Engine Development

NASA Technical Reports Server (NTRS)

Litchford, Ron J.; Foote, John P.; Clifton, W. B.; Hickman, Robert R.; Wang, Ten-See; Dobson, Christopher C.

2011-01-01

An arc-heater driven hyperthermal convective environments simulator was recently developed and commissioned for long duration hot hydrogen exposure of nuclear thermal rocket materials. This newly established non-nuclear testing capability uses a high-power, multi-gas, wall-stabilized constricted arc-heater to produce hightemperature pressurized hydrogen flows representative of nuclear reactor core environments, excepting radiation effects, and is intended to serve as a low-cost facility for supporting non-nuclear developmental testing of hightemperature fissile fuels and structural materials. The resulting reactor environments simulator represents a valuable addition to the available inventory of non-nuclear test facilities and is uniquely capable of investigating and characterizing candidate fuel/structural materials, improving associated processing/fabrication techniques, and simulating reactor thermal hydraulics. This paper summarizes facility design and engineering development efforts and reports baseline operational characteristics as determined from a series of performance mapping and long duration capability demonstration tests. Potential follow-on developmental strategies are also suggested in view of the technical and policy challenges ahead. Keywords: Nuclear Rocket Engine, Reactor Environments, Non-Nuclear Testing, Fissile Fuel Development.

Evolving Concepts and Teaching Approaches In Tectonics and Sedimentation.

ERIC Educational Resources Information Center

Graham, Stephan Alan

1983-01-01

Discusses five recent advances in sedimentary tectonics, noting how they are incorporated into college curricula. Advances discussed include basin type, tectonic setting, facies analysis (in conjunction with basin type/setting), stratigraphic analysis of reflection seismic data, and quantitative analysis of subsidence histories of sedimentary…

Mare Orientale: Widely Accepted Large Impact or a Regular Tectonic Depression?

NASA Astrophysics Data System (ADS)

Kochemasov, G. G.

2018-04-01

Mare Orientale is one of the critical features on Moon surface explaining its tectonics. The impact origin of it is widely accepted, but an attentive examination shows that this large Mare is a part of endogenous tectonic structure, not a random impact.

Analysis of Online Information Searching for Cardiovascular Diseases on a Consumer Health Information Portal

PubMed Central

Jadhav, Ashutosh; Sheth, Amit; Pathak, Jyotishman

2014-01-01

Since the early 2000’s, Internet usage for health information searching has increased significantly. Studying search queries can help us to understand users “information need” and how do they formulate search queries (“expression of information need”). Although cardiovascular diseases (CVD) affect a large percentage of the population, few studies have investigated how and what users search for CVD. We address this knowledge gap in the community by analyzing a large corpus of 10 million CVD related search queries from MayoClinic.com. Using UMLS MetaMap and UMLS semantic types/concepts, we developed a rule-based approach to categorize the queries into 14 health categories. We analyzed structural properties, types (keyword-based/Wh-questions/Yes-No questions) and linguistic structure of the queries. Our results show that the most searched health categories are ‘Diseases/Conditions’, ‘Vital-Sings’, ‘Symptoms’ and ‘Living-with’. CVD queries are longer and are predominantly keyword-based. This study extends our knowledge about online health information searching and provides useful insights for Web search engines and health websites. PMID:25954380

There comes a baby! What should I do? Smartphones' pregnancy-related applications: A web-based overview.

PubMed

Bert, Fabrizio; Passi, Stefano; Scaioli, Giacomo; Gualano, Maria R; Siliquini, Roberta

2016-09-01

Our article aims to give an overview of the most mentioned smartphones' pregnancy-related applications (Apps). A keywords string with selected keywords was entered both in a general search engine (Google(®)) and PubMed. While PubMed returned no pertinent results, a total of 370 web pages were found on Google(®), and 146 of them were selected. All the pregnancy-related Apps cited at least eight times were included. Information about App's producer, price, contents, privacy policy, and presence of a scientific board was collected. Finally, nine apps were considered. The majority of them were free and available in the two main online markets (Apple(®) App Store and Android(®) Google Play). Five apps presented a privacy policy statement, while a scientific board was mentioned in only three. Further studies are needed in order to deepen the knowledge regarding the main risks of these devices, such as privacy loss, contents control concerns, the digital divide and a potential humanization reduction. © The Author(s) 2015.

Non-orthodontic intervention and non-nutritive sucking behaviours: A literature review.

PubMed

Tanny, Liyana; Huang, Boyen; Naung, Noel Ye; Currie, Geoffrey

2018-04-01

Anterior open bite (AOB) is one of the most complex malocclusions to manage. AOB is caused by either by skeletal, genetic or environmental factors. Numerous treatment options are currently utilised to manage AOB. These vary from non-invasive behavioural shaping to orthodontic and surgical interventions. This paper reviews the available orthodontic and non-orthodontic interventions used in the management of AOB. The literature review was carried out using the PubMed search engine from the first of January 2000 to the first of June 2017. Two major keywords (open bite and anterior open bite) were used in addition to 23 minor keywords in the review. AOB is one of the most complex malocclusions to treat with high relapse rates. Long term outcome in treatments of patients with AOB was substantially low. Relapse rates were not taken into consideration for some of the literature reviewed. Despite limitations of the literature, it is recommended that orofacial myofunctional therapy (OMT) and non-orthodontic intervention (NOI) be used in conjunction as an effective treatment option for Anterior Open Bite. Copyright © 2018. Published by Elsevier Taiwan.

Goechemical and Hydrogeochemical Properties of Cappadocia Geothermal Province

NASA Astrophysics Data System (ADS)

Furkan Sener, Mehmet; Sener, Mehmet; Uysal, Tonguc

2016-04-01

In order to determine the geothermal resource potential of Niǧde, Nevşehir and Aksaray provinces in Central Anatolian Volcanic Province (CAVP), geothermal fluids, surface water, and alteration rock samples from the Cappadocia volcanic zone in Turkey were investigated for their geochemical and stable isotopic characteristics in light of published geological and tectonic studies. Accordingly, the Cappadocia Geothermal Province (CGP) has two different geothermal systems located along tectonic zones including five active and two potential geothermal fields, which are located between Tuzgölü Fault Zone and Keçiboyduran-Melendiz Fault and north of Keçiboyduran-Melendiz Fault. Based on water chemistry and isotope compositions, samples from the first area are characterized by Ca-Mg-HCO3 ve Ca-HCO3 type mineral poor waters and Ca-Na-SO4 and Ca-Mg-SO4 type for the cold waters and the hot waters, respectively, whereas hot waters from the second area are Na-Cl-HCO3 and Ca-Na-HCO3 type mineral poor waters. According to δ18O and δ2H isotope studies, the geothermal waters are fed from meteoric waters. Results of silica geothermometer indicate that the reservoir temperature of Dertalan, Melendiz Mount, Keçiboyduran Mount, Hasan Mount (Keçikalesi), Ziga, Acıgöl, and Derinkuyu geothermal waters are 150-173 oC, 88-117 oC, 91-120 oC, 94-122 oC, 131-156 oC, 157-179 oC; 152-174 oC and 102-130 oC, respectively. The REE composition of geothermal fluids, surface water, and mineral precipitates indicate that temperature has a strong effect on REE fractionation of the sampled fluids. Eu- and Ce- anomalies (Eu/Eu*, Ce/Ce*) are visible in several samples, which are related to the inheritance from the host reservoir rocks and redox-controlled fractionation of these elements during water-rock interactions. REE and Yttrium geochemistry results of altered rock samples and water samples, which were taken from same locations exhibited quite similar features in each system. Hence, it was conclude that the same hydrothermal fluid in geothermal system was reached to the surface and interacted with the surface rocks. Our conceptual geothermal model for Cappadocia Geothermal Province based on our geochemical and hydrogeochemical data in combination with geological and geophysical information suggest that the geothermal resources in this region are controlled by primary (active fault) and secondary (buried fault) tectonic belts. Further, our geochemical data indicate the Paleozoic-Mesozoic marble and gneiss being the reservoir rocks. Geogradient and impending heat fluxes to the surface with a possible crustal thinning, which was developed after regional tectonic activities during the Late Pliocene-Quaternary period, constitutes the heat sources. In addition, our study suggest that the Quaternary tuff and ignimbrites of Cappadocia Volcanics represent the seal rock of the geothermal system. In conclusion this study provide evidence for a significant geothermal potential in the Cappadocia region with well-defined seal rocks. However, further studies are needed to resolve the geothermal fluid source problem. Keywords: Cappadocia, geothermal systems, geochemistry, rare earth elements, hydrogeochemistry, hydrothermal alteration.

Quantification of fluvial response to tectonic deformation in the Central Pontides, Turkey; inferences from OSL dating of fluvial terraces

NASA Astrophysics Data System (ADS)

McClain, Kevin; Yıldırım, Cengiz; Çiner, Attila; Akif Sarıkaya, M.; Şahin, Sefa; Özcan, Orkan; Güneç Kıyak, Nafiye; Öztürk, Tuǧba

2017-04-01

From Late Miocene to present, Anatolia's rapid counterclockwise movement, which increases in velocity towards the Hellenic Arc, has formed the North Anatolian Fault (NAF), a dextral transform fault along the Anatolia-Eurasia plate boundary and the northern margin of the Central Anatolian Plateau (CAP). A zone of transpression referred to as the Central Pontides exists between the broad restraining bend of the NAF and the Black Sea Basin, uplifting what is interpreted as a detached flower structure. Dating of Quaternary landforms in the eastern flank of the Central Pontides has helped to understand its recent deformation. However, in the western flank of the Central Pontides there is an absence of Quaternary studies, relatively quiet modern seismicity, and difficulties locating or observing fault scarps. This led us to use optically stimulated luminescence dating (OSL-dating) of fluvial terrace sediments and the study of geomorphic features to gain insight into the influence of climate and tectonics on landscape evolution of this area. In this area, the Filyos River crosses the Karabük Fault (reverse fault) and deeply incises a gorge through the Karabük Range before flowing towards the Black Sea. In the gorge an abundance of indicators of tectonic deformation were mapped, such as hanging valleys, wind gaps, bedrock gorges, landslides, steep V-shaped channels, tilted basins, as well as fluvial strath terraces. In particular, strath terraces of at least 8 levels within just 1.5 km of horizontal distance were examined. We used OSL-dating to estimate five deposition ages of fluvial strath terrace sediments, leading to an estimation of incision and uplift rates over time. Using three samples per terrace with strath elevations of 246 ± 0.2 m, 105.49 ± 0.2 m, 43.6 ± 0.2 m, 15.3 ± 0.2 m and 3.6 ± 0.2 m above the Filyos River, we determined corresponding ages of 841 ± 76 ka, 681 ± 49 ka, 386 ± 18 ka, 88 ± 5.1 ka and 50.9 ± 2.8 ka. Incision rates over time (oldest terrace to youngest) suggest uplift of 0.29 ± 0.03 mm/y, 0.16 ± 0.01 mm/y, 0.10 ± 0.01 mm/y, 0.17 ± 0.01 mm/y and 0.07 ± 0.004 mm/y. Collectively, our ages infer decelerating fluvial incision and rock uplift rates in the Karabük Range of the Central Pontides. The highest rate that belongs to oldest terrace level (841 ± 76 ka) also implies long-term mean uplift, which is well correlated with long term ( 350 ka) mean uplift rate obtained from fluvial terraces in the eastern flank of the (Gökırmak Basin) Central Pontides. These results indicate Quaternary activity of the Karabük Fault despite the fact that very low modern seismicity and partition of strain in the north of the North Anatolian Fault. Keywords: Tectonics, Geomorphology, Fluvial Terrace, OSL Dating, Central Pontides, North Anatolian Fault, Filyos River, Turkey, Central Anatolian Plateau

Regional Moment Tensor Analysis of Earthquakes in Iran for 2010 to 2017 Using In-Country Data

NASA Astrophysics Data System (ADS)

Graybeal, D.; Braunmiller, J.

2017-12-01

Located in the middle of the Arabia-Eurasia continental collision, Iran is one of the most tectonically diverse and seismically active countries in the world. Until recently, however, seismic source parameter studies had to rely on teleseismic data or on data from temporary local arrays, which limited the scope of investigations. Relatively new broadband seismic networks operated by the Iranian Institute of Engineering Seismology (IIEES) and the Iranian Seismological Center (IRSC) currently consist of more than 100 stations and allow, for the first time, routine three-component full-waveform regional moment tensor analysis of the numerous M≥4.0 earthquakes that occur throughout the country. We use openly available, in-country data and include data from nearby permanent broadband stations available through IRIS and EIDA to improve azimuthal coverage for events in border regions. For the period from 2010 to 2017, we have obtained about 500 moment tensors for earthquakes ranging from Mw=3.6 to 7.8. The resulting database provides a unique, detailed view of deformation styles and earthquake depths in Iran. Overall, we find mainly thrust and strike-slip mechanisms as expected considering the convergent tectonic setting. Our magnitudes (Mw) are slightly smaller than ML and mb but comparable to Mw as reported in global catalogs (USGS ANSS). Event depths average about 3 km shallower than in global catalogs and are well constrained considering the capability of regional waveforms to resolve earthquake depth. Our dataset also contains several large magnitude main shock-aftershock sequences from different tectonic provinces, including the 2012 Ahar-Varzeghan (Mw=6.4), 2013 Kaki (Mw=6.5), and 2014 Murmuri (Mw=6.2) earthquakes. The most significant result in terms of seismogenesis and seismic hazard is that the vast majority of earthquakes occur at shallow depth, not in deeper basement. Our findings indicate that more than 80% of crustal seismicity in Iran likely occurs at depths of 12 km or less.

Tectonics and volcanism on Mars: a compared remote sensing analysis with earthly geostructures

NASA Astrophysics Data System (ADS)

Baggio, Paolo; Ancona, M. A.; Callegari, I.; Pinori, S.; Vercellone, S.

1999-12-01

The recent knowledge on Mars' lithosphere evolution does not find yet sufficient analogies with the Earth's tectonic models. The Viking image analysis seems to be even now frequently, rather fragmentary, and do not permits to express any coherent relationships among the different detected phenomena. Therefore, today it is impossible to support any reliable kinematic hypothesis. The Remote-Sensing interpretation is addressed to a Viking image mosaic of the known Tharsis Montes region and particularly focused on the Arsia Mons volcano. Several previously unknown lineaments, not directly linked to volcano-tectonics, were detected. Their mutual relationships recall transcurrent kinematics that could be related to similar geostructural models known in the Earth plate tectonic dynamics. Several concordant relationships between the Arsia Mons volcano and the brittle extensive tectonic features of earthly Etnean district (Sicily, South Italy), interpreted on Landsat TM images, were pointed out. These analogies coupled with the recently confirmed strato- volcano topology of Tharsis Montes (Head and Wilson), the layout distribution of the effusive centers (Arsia, Pavonis and Ascraeus Montes), the new tectonic lineaments and the morphological features, suggest the hypothesis of a plate tectonic volcanic region. The frame could be an example in agreement with the most recent interpretation of Mars (Sleep). A buried circular body, previously incorrectly interpreted as a great landslide event from the western slope of Arsia Mons volcano, seems really to be a more ancient volcanic structure (Arsia Mons Senilis), which location is in evident relation with the interpreted new transcurrent tectonic system.

[Biomedical information on the internet using search engines. A one-year trial].

PubMed

Corrao, Salvatore; Leone, Francesco; Arnone, Sabrina

2004-01-01

The internet is a communication medium and content distributor that provide information in the general sense but it could be of great utility regarding as the search and retrieval of biomedical information. Search engines represent a great deal to rapidly find information on the net. However, we do not know whether general search engines and meta-search ones are reliable in order to find useful and validated biomedical information. The aim of our study was to verify the reproducibility of a search by key-words (pediatric or evidence) using 9 international search engines and 1 meta-search engine at the baseline and after a one year period. We analysed the first 20 citations as output of each searching. We evaluated the formal quality of Web-sites and their domain extensions. Moreover, we compared the output of each search at the start of this study and after a one year period and we considered as a criterion of reliability the number of Web-sites cited again. We found some interesting results that are reported throughout the text. Our findings point out an extreme dynamicity of the information on the Web and, for this reason, we advice a great caution when someone want to use search and meta-search engines as a tool for searching and retrieve reliable biomedical information. On the other hand, some search and meta-search engines could be very useful as a first step searching for defining better a search and, moreover, for finding institutional Web-sites too. This paper allows to know a more conscious approach to the internet biomedical information universe.

Plate Tectonics: A Framework for Understanding Our Living Planet.

ERIC Educational Resources Information Center

Achache, Jose

1987-01-01

Discusses some of the events leading to the development of the theory of plate tectonics. Describes how seismic, volcanic, and tectonic features observed at the surface of the planet are now seen as a consequence of intense internal activity, and makes suggestions about their further investigation. (TW)

Plate Tectonic Cycle. K-6 Science Curriculum.

ERIC Educational Resources Information Center

Blueford, J. R.; And Others

Plate Tectonics Cycle is one of the units of a K-6 unified science curriculum program. The unit consists of four organizing sub-themes: (1) volcanoes (covering formation, distribution, and major volcanic groups); (2) earthquakes (with investigations on wave movements, seismograms and sub-suface earth currents); (3) plate tectonics (providing maps…

Tectonic evolution of the Archaean high-grade terrain of South India

NASA Technical Reports Server (NTRS)

Ramakrishnan, M.

1988-01-01

The southern Indian shield consists of three major tectonic provinces viz., (1) Dharwar Craton, (2) Eastern Ghat Mobile Belt, and (3) Pandyan Mobile Belt. An understanding of their mutual relations is crucial for formulating crustal evolution models. The tectonic evolution of these provinces is summarized.

Philippine microplate tectonics and hydrocarbon exploration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gallagher, J.J. Jr.

1986-07-01

Hydrocarbon traps in the Philippine Islands developed during a long, complex history of microplate tectonics. Carbonate and clastic stratigraphic traps formed during Mesozoic and early Cenozoic rifting and drifting. Hydrocarbons, generated in deep rift basins, migrated to the traps during drifting. Later Cenozoic compressional tectonic activity and concomitant faulting enhanced some traps and destroyed others. Seismic data offshore from Palawan Island reveal the early trap histories. Later trap histories can be interpreted from seismic, outcrop, and remote-sensing data. Understanding the microplate tectonic history of the Philippines is the key to interpreting trap histories.

Extrusive and Intrusive Magmatism Greatly Influence the Tectonic Mode of Earth-Like Planets

NASA Astrophysics Data System (ADS)

Lourenco, D.; Tackley, P. J.; Rozel, A.; Ballmer, M.

2017-09-01

Plate tectonics on Earth-like planets is typically modelling using a strongly temperature-dependent visco-plastic rheology. Previous analyses have generally focussed on purely thermal convection. However, we have shown that the influence of compositional heterogeneity in the form of continental or oceanic crust can greatly influence plate tectonics by making it easier (i.e. it occurs at a lower yield stress or friction coefficient). Here we present detailed results on this topic, in particular focussing on the influence of intrusive vs. extrusive magmatism on the tectonic mode.

Venus: Mantle convection, hotspots, and tectonics

NASA Technical Reports Server (NTRS)

Phillips, R. J.

1989-01-01

The putative paradigm that planets of the same size and mass have the same tectonic style led to the adaptation of the mechanisms of terrestrial plate tectonics as the a priori model of the way Venus should behave. Data acquired over the last decade by Pioneer Venus, Venera, and ground-based radar have modified this view sharply and have illuminated the lack of detailed understanding of the plate tectonic mechanism. For reference, terrestrial mechanisms are briefly reviewed. Venusian lithospheric divergence, hotspot model, and horizontal deformation theories are proposed and examined.

Geochemical evolution of Cenozoic-Cretaceous magmatism and its relation to tectonic setting, southwestern Idaho, U.S.A

NASA Technical Reports Server (NTRS)

Norman, Marc D.; Leeman, William P.

1989-01-01

The relationships between Cretaceous to Neogene magmatism and the tectonic setting of southwestern and central Idaho are evaluated. An overview of the tectonics and geology of the northwestern U.S. is presented. Major element, trace element, and Sr, Pb, and Nd isotopic data for the region are used to place constraints on magma source characteristics, the manner in which the magmatic sources evolved through time, and the nature of interactions among mantle and crustal domains in response to changing tectonic environment.

Looking for Plate Tectonics in all the wrong fluids

NASA Astrophysics Data System (ADS)

Davaille, Anne

2017-04-01

Ever since the theory of Plate Tectonics in the 1960's, the dream of the geomodeler has been to generate plate tectonics self-consistently from thermal convection in the laboratory. By selfconsistenly, I mean that the configuration of the plate boundaries is in no way specified a priori, so that the plates develop and are wholly consumed without intervention from the modeler. The reciepe is simple : put a well-chosen fluid in a fishtank heated from below and cooled from above, wait and see. But the « well-chosen » is the difficult part... and the interesting one. Plate tectonics is occuring on Earth because of the characteristics of the lithosphere rheology. The latter are complex to estimate as they depend on temperature, pressure, phase, water content, chemistry, strain rate, memory and scale. As a result, the ingredients necessary for plate tectonics are still debated, and it would be useful to find an analog fluid who could reproduce plate tectonics in the laboratory. I have therefore spent the last 25 years to try out fluids, and I shall present a number of failures to generate plate tectonics using polymers, colloids, ketchup, milk, chocolate, sugar, oils. To understand why they failed is important to narrow down the « well-chosen » fluid.

Delineation of tectonic provinces of New York state as a component of seismic-hazard evaluation

USGS Publications Warehouse

Fakundiny, R.H.

2004-01-01

Seismic-hazard evaluations in the eastern United States must be based on interpretations of the composition and form of Proterozoic basement-rock terranes and overlying Paleozoic strata, and on factors that can cause relative movements among their units, rather than Phanerozoic orogenic structures, which may be independent of modern tectonics. The tectonic-province concept is a major part of both probabilistic and deterministic seismic-hazard evaluations, yet those that have been proposed to date have not attempted to geographically correlate modern earthquakes with regional basement structure. Comparison of basement terrane (megablock) boundaries with the spatial pattern of modern seismicity may lead to the mechanically sound definition of tectonic provinces, and thus, better seismic-hazard evaluation capability than is currently available. Delineation of megablock boundaries will require research on the many factors that affect their structure and movement. This paper discusses and groups these factors into two broad categories-megablock tectonics in relation to seismicity and regional horizontal-compressive stresses, with megablock tectonics divided into subcategories of basement, overlying strata, regional lineaments, basement tectonic terranes, earthquake epicenter distribution, and epeirogeny, and compressive stresses divided into pop-ups and the contemporary maximum horizontal-compressive stress field. A list presenting four to nine proposed research topics for each of these categories is given at the end.

Crustal deformation: Earth vs Venus

NASA Technical Reports Server (NTRS)

Turcotte, D. L.

1989-01-01

It is timely to consider the possible tectonic regimes on Venus both in terms of what is known about Venus and in terms of deformation mechanisms operative on the earth. Plate tectonic phenomena dominate tectonics on the earth. Horizontal displacements are associated with the creation of new crust at ridges and destruction of crust at trenches. The presence of plate tectonics on Venus is debated, but there is certainly no evidence for the trenches associated with subduction on the earth. An essential question is what kind of tectonics can be expected if there is no plate tectonics on Venus. Mars and the Moon are reference examples. Volcanic constructs appear to play a dominant role on Mars but their role on Venus is not clear. On single plate planets and satellites, tectonic structures are often associated with thermal stresses. Cooling of a planet leads to thermal contraction and surface compressive features. Delamination has been propsed for Venus by several authors. Delamination is associated with the subduction of the mantle lithosphere and possibly the lower crust but not the upper crust. The surface manifestations of delamination are unclear. There is some evidence that delamination is occurring beneath the Transverse Ranges in California. Delamination will certainly lead to lithospheric thinning and is likely to lead to uplift and crustal thinning.

Thoracic Surgery Information on the Internet: A Multilingual Quality Assessment

PubMed Central

Davaris, Myles; Barnett, Stephen; Abouassaly, Robert

2017-01-01

Background Previous data suggest that quality of Internet information regarding surgical conditions and their treatments is variable. However, no comprehensive analysis of website quality exists for thoracic surgery. Objective The aim of this study was to quantify website quality in a multilingual setting using an international standard for assessment. Methods Health On the Net (HON) principles may be applied to websites using an automated toolbar function. We used the English, French, Spanish, and German Google search engines to identify 12,000 websites using keywords related to thoracic conditions and procedures. The first 150 websites returned by each keyword in each language were examined. We compared website quality to assess for tertile (is the quality better in first, second, or third 50 websites returned) and language differences. A further analysis of the English site types was undertaken performing a comparative analysis of website provider types. Results Overall, there are a considerable number of websites devoted to thoracic surgery: “lung cancer” returned over 150 million websites. About 7.85% (940/11,967) of websites are HON-accredited with differences by search term (P<.001) and tertiles (P<.001) of the first 150 websites, but not between languages. Oncological keywords regarding conditions and procedures were found to return a higher percentage of HON-accreditation. The percentage of HON-accredited sites was similar across all four languages (P=.77). In general, the first tertile contained a higher percentage of HON-accredited sites for every keyword. Conclusions Clinicians should appreciate the lack of validation of the majority of thoracic websites, with discrepancies in quality and number of websites across conditions and procedures. These differences appear similar regardless of language. An opportunity exists for clinicians to participate in the development of informative, ethical, and reliable health websites on the Internet and direct patients to them. PMID:28500021

Thoracic Surgery Information on the Internet: A Multilingual Quality Assessment.

PubMed

Davaris, Myles; Barnett, Stephen; Abouassaly, Robert; Lawrentschuk, Nathan

2017-05-12

Previous data suggest that quality of Internet information regarding surgical conditions and their treatments is variable. However, no comprehensive analysis of website quality exists for thoracic surgery. The aim of this study was to quantify website quality in a multilingual setting using an international standard for assessment. Health On the Net (HON) principles may be applied to websites using an automated toolbar function. We used the English, French, Spanish, and German Google search engines to identify 12,000 websites using keywords related to thoracic conditions and procedures. The first 150 websites returned by each keyword in each language were examined. We compared website quality to assess for tertile (is the quality better in first, second, or third 50 websites returned) and language differences. A further analysis of the English site types was undertaken performing a comparative analysis of website provider types. Overall, there are a considerable number of websites devoted to thoracic surgery: "lung cancer" returned over 150 million websites. About 7.85% (940/11,967) of websites are HON-accredited with differences by search term (P<.001) and tertiles (P<.001) of the first 150 websites, but not between languages. Oncological keywords regarding conditions and procedures were found to return a higher percentage of HON-accreditation. The percentage of HON-accredited sites was similar across all four languages (P=.77). In general, the first tertile contained a higher percentage of HON-accredited sites for every keyword. Clinicians should appreciate the lack of validation of the majority of thoracic websites, with discrepancies in quality and number of websites across conditions and procedures. These differences appear similar regardless of language. An opportunity exists for clinicians to participate in the development of informative, ethical, and reliable health websites on the Internet and direct patients to them. ©Myles Davaris, Stephen Barnett, Robert Abouassaly, Nathan Lawrentschuk. Originally published in the Interactive Journal of Medical Research (http://www.i-jmr.org/), 12.05.2017.

Global Change Master Directory (GCMD) Keywords and Their Applications in Earth Science Data Discovery

NASA Astrophysics Data System (ADS)

Aleman, A.

2017-12-01

This presentation will provide an overview and discussion of the Global Change Master Directory (GCMD) Keywords and their applications in Earth science data discovery. The GCMD Keywords are a hierarchical set of controlled keywords covering the Earth science disciplines, including: science keywords, service keywords, data centers, projects, location, data resolution, instruments and platforms. Controlled vocabularies (keywords) help users accurately, consistently and comprehensively categorize their data and also allow for the precise search and subsequent retrieval of data. The GCMD Keywords are a community resource and are developed collaboratively with input from various stakeholders, including GCMD staff, keyword users and metadata providers. The GCMD Keyword Landing Page and GCMD Keyword Community Forum provide access to keyword resources and an area for discussion of topics related to the GCMD Keywords. See https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords

Faults and structure in the Pierre Shale, central south Dakota

USGS Publications Warehouse

Nichols, Thomas C.; Collins, Donley S.; Jones-Cecil, Meridee; Swolfs, Henri S.

1994-01-01

Numerous faults observed at the surface and (or) determined by geometric and geophysical methods to be present as much as several hundred meters below the surface (near-surface faults) have been mapped in a 2,000-km2 area west of Pierre, S. Dakota. Many of these faults surround an east-west-trending structural high that has been mapped on the lower part of the Virgin Creek Member of the Pierre Shale. Generally, the geometry and displacement of many of the faults precludes slumping from surficial erosion as a mechanism to explain the faults. Seismic-reflection data indicate that several of the faults directly overlie faults in Precambrian basement that have cumulative vertical displacements of as much as 340 m. The structural high is interpreted to have been uplifted by displacements along faults that cut Upper Cretaceous sedimentary rocks. Recent low-level seismicity and fluvial-geomorphic studies of stream patterns, gradients, and orders suggest that rejuvenation of drainages may be taking place as a result of rebound or other tectonic activity. The studies indicate that repeated uplift and subsidence may have been the cause of extensive faulting mapped in the Pierre Shale since its deposition in Cretaceous time. Surficial fault displacements that cause damage to engineered structures are thought to be the result of construction-induced rebound in the Pierre Shale, although tectonic uplift cannot be ruled out as a cause.

Searching the scientific literature: implications for quantitative and qualitative reviews.

PubMed

Wu, Yelena P; Aylward, Brandon S; Roberts, Michael C; Evans, Spencer C

2012-08-01

Literature reviews are an essential step in the research process and are included in all empirical and review articles. Electronic databases are commonly used to gather this literature. However, several factors can affect the extent to which relevant articles are retrieved, influencing future research and conclusions drawn. The current project examined articles obtained by comparable search strategies in two electronic archives using an exemplar search to illustrate factors that authors should consider when designing their own search strategies. Specifically, literature searches were conducted in PsycINFO and PubMed targeting review articles on two exemplar disorders (bipolar disorder and attention deficit/hyperactivity disorder) and issues of classification and/or differential diagnosis. Articles were coded for relevance and characteristics of article content. The two search engines yielded significantly different proportions of relevant articles overall and by disorder. Keywords differed across search engines for the relevant articles identified. Based on these results, it is recommended that when gathering literature for review papers, multiple search engines should be used, and search syntax and strategies be tailored to the unique capabilities of particular engines. For meta-analyses and systematic reviews, authors may consider reporting the extent to which different archives or sources yielded relevant articles for their particular review. Copyright © 2012 Elsevier Ltd. All rights reserved.

The influence of mantle refertilisation on the formation of TTGs in a plume-lid tectonics setting

NASA Astrophysics Data System (ADS)

Fischer, R.; Gerya, T.

2017-12-01

Higher amounts of radiogenic elements and leftover primordial heat in the early Earth both contribute to the increased temperature in the Earth's interior and it is mainly this increased mantle potential temperature that controls the dynamics of the crust and upper mantle and the predominant style of tectonics in the Early Earth. The increased upper mantle temperature precludes the modern plate tectonics regime and stabilizes another type of global tectonics often called plume-lid tectonics (Fischer and Gerya, 2016) or 'plutonic squishy lid' tectonics(Rozel et al., 2017). Plume-lid tectonics is dominated by intrusive mantle-derived magmatism which results in a thickening of the overlaying crust. The overthickened basaltic crust is transformed into eclogite and episodically recycled back into the mantle. Melt extraction from hydrated partially molten basaltic crust leads to the production of primordial tonalite-trondhjemite-granodiorite (TTG) continental crust. TTGs make up over half of the Archean crust and can be classied into low-, medium- and high-pressure types (Moyen, 2011). Field studies show that the three different types (low-, medium- and high-pressure) appear in a ratio of 20%, 60% and 20% (Moyen, 2011). Numerical models of plume-lid tectonics generally agree very well with these values (Rozel et al., 2017) but also show that the ratio between the three different TTG types varies greatly during the two phases of the plume-lid tectonics cycle: growth phase and overturn phase. Melt productivity of the mantle decreases rapidly after removal of the garnet and clinopyroxene components. Addition of new garnet and clinopyroxene-rich material into the harzburgitic residue should lead to a refertilised lherzolite which could potentially yield new melt (Bédard, 2006). Mixing of eclogite drips back into the mantle can lead to the geochemical refertilisation of already depleted mantle and allow for further extraction of melt (Bédard, 2006). We will explore this process of mantle refertilisation in our 3D petrological-magmatic-thermomechanical numerical modelling experiments and study its influence on the three types of TTGs during different phases of the plume-lid tectonics cycle.

Large-scale geomorphology: Classical concepts reconciled and integrated with contemporary ideas via a surface processes model

NASA Astrophysics Data System (ADS)

Kooi, Henk; Beaumont, Christopher

1996-02-01

Linear systems analysis is used to investigate the response of a surface processes model (SPM) to tectonic forcing. The SPM calculates subcontinental scale denudational landscape evolution on geological timescales (1 to hundreds of million years) as the result of simultaneous hillslope transport, modeled by diffusion, and fluvial transport, modeled by advection and reaction. The tectonically forced SPM accommodates the large-scale behavior envisaged in classical and contemporary conceptual geomorphic models and provides a framework for their integration and unification. The following three model scales are considered: micro-, meso-, and macroscale. The concepts of dynamic equilibrium and grade are quantified at the microscale for segments of uniform gradient subject to tectonic uplift. At the larger meso- and macroscales (which represent individual interfluves and landscapes including a number of drainage basins, respectively) the system response to tectonic forcing is linear for uplift geometries that are symmetric with respect to baselevel and which impose a fully integrated drainage to baselevel. For these linear models the response time and the transfer function as a function of scale characterize the model behavior. Numerical experiments show that the styles of landscape evolution depend critically on the timescales of the tectonic processes in relation to the response time of the landscape. When tectonic timescales are much longer than the landscape response time, the resulting dynamic equilibrium landscapes correspond to those envisaged by Hack (1960). When tectonic timescales are of the same order as the landscape response time and when tectonic variations take the form of pulses (much shorter than the response time), evolving landscapes conform to the Penck type (1972) and to the Davis (1889, 1899) and King (1953, 1962) type frameworks, respectively. The behavior of the SPM highlights the importance of phase shifts or delays of the landform response and sediment yield in relation to the tectonic forcing. Finally, nonlinear behavior resulting from more general uplift geometries is discussed. A number of model experiments illustrate the importance of "fundamental form," which is an expression of the conformity of antecedent topography with the current tectonic regime. Lack of conformity leads to models that exhibit internal thresholds and a complex response.

Rapid automatic keyword extraction for information retrieval and analysis

DOEpatents

Rose, Stuart J [Richland, WA; Cowley,; E, Wendy [Richland, WA; Crow, Vernon L [Richland, WA; Cramer, Nicholas O [Richland, WA

2012-03-06

Methods and systems for rapid automatic keyword extraction for information retrieval and analysis. Embodiments can include parsing words in an individual document by delimiters, stop words, or both in order to identify candidate keywords. Word scores for each word within the candidate keywords are then calculated based on a function of co-occurrence degree, co-occurrence frequency, or both. Based on a function of the word scores for words within the candidate keyword, a keyword score is calculated for each of the candidate keywords. A portion of the candidate keywords are then extracted as keywords based, at least in part, on the candidate keywords having the highest keyword scores.

Extending Whole-earth Tectonics To The Terrestrial Planets

NASA Astrophysics Data System (ADS)

Baker, V. R.; Maruyama, S.; Dohm, J. M.

Based on the need to explain a great many geological and geophysical anomalies on Mars, and stimulated by the new results from the Mars Global Surveyor Mission, we propose a conceptual model of whole-EARTH (Episodic Annular Revolving Thermal Hydrologic) tectonics for the long-term evolution of terrestrial planets. The theory emphasizes (1) the importance of water in planetary evolution, and (2) the physi- cal transitions in modes of mantle convection in relation to planetary heat produc- tion. Depending on their first-order geophysical parameters and following accretion and differentiation from volatile-rich planetessimals, terrestrial planets should evolve through various stages of mantle convection, including magma ocean, plate tectonic, and stagnant lid processes. If a water ocean is able to condense from the planet's early steam atmosphere, an early regime of plate tectonics will follow the initial magma ocean. This definitely happened on earth, probably on Mars, and possibly on Venus. The Mars history led to transfer of large amounts of water to the mantle during the pe- riod of heavy bombardment. Termination of plate tectonics on Mars during the heavy bombardment period led to initiation of superplumes at Tharsis and Elysium, where long-persistent volcanism and water outbursts dominated much of later Martian his- tory. For Venus, warming of the early sun made the surface ocean unstable, eliminating its early plate-tectonic regime. Although Venus now experiences stagnant-lid convec- tion with episodic mantle overturns, the water subducted to its lower mantle during the ancient plate-tectonic regime manifests itself in the initation of volatile-rich plumes that dominate its current tectonic regime.

National Register of Research Projects, 1986/87. Part 2A: Natural sciences. Physical, engineering and related sciences (modified projects)

NASA Astrophysics Data System (ADS)

1988-08-01

This Register is intended to serve as a source of information on research which is being conducted in all fields (both natural and human sciences) in the Republic of South Africa. New and current research projects that were commenced or modified during 1986 and 1987, on which information was received by the compilers until January 1988, are included, with the exception of confidential projects. Project titles and keywords are presented in the language as supplied, and the classifications are based on those provided by the primary sources.

Copernican tectonic activities in the northwestern Imbrium region of the Moon

NASA Astrophysics Data System (ADS)

Daket, Yuko; Yamaji, Atsushi; Sato, Katsushi

2015-04-01

Mare ridges and lobate scarps are the manifestations of horizontal compression in the shallow part of the Moon. Conventionally, tectonism within mascon basins has been thought to originate from mascon loading which is syndepositional tectonics (e.g., Solomon and Head, 1980). However, Ono et al. (2009) have pointed out that the subsurface tectonic structures beneath some mare ridges in Serenitatis appeared to be formed after the deposition of mare strata. Watters et al. (2010) also reported Copernican lobate scarps. Those young deformations cannot be explained by the mascon loading and are possibly ascribed to global cooling, orbital evolution and/or regional factors. Since mare ridges are topographically larger than lobate scarps, they might have large contribution to the recent contraction. In this study, we estimated until when the tectonic activities of mare ridges lasted in the northwestern Imbrium region. In order to infer the timing of the latest ages of tectonic activities, we used craters dislocated by the thrust faults that run along to the mare ridges in the study area. The ages of dislocated craters indicate the oldest estimate of the latest tectonic activity of the faults, because those craters must have existed during the tectonic activities. The ages of craters are inferred by the degradation levels classified by Trask (1971). We found ~450 dislocated craters in the study area. About 40 of them are smaller than 100 meter in diameter. Sub-hundred-meter-sized craters that still maintain their morphology sharp are classified into Copernican Period. Those small dislocated craters are interspersed all over the region, indicating that the most of the mare ridges in the study area were tectonically active in Copernican Period. In addition, we also found two sub-hundred-meter-sized craters dislocated by a graben at the west of Promontorium Laplace, indicating horizontal extension existed at Copernican Period. Consequently, tectonic activities in the study area lasted until recently. Those young tectonic activities are too young to be explained by mascon loading hypothesis. Tectonism induced by global cooling or orbital evolution are possible origins for the young horizontal compression. However, they cannot explain the recent extension. Our study area is located in PKT region where the heat-producing elements are more abundant than surrounding areas. Therefore, regional cooling would be a reasonable explanation for the young extensional tectonics. References Ono, T., A. Kumamoto, H. Nakagawa, Y. Yamaguchi, S. Oshigami, A. Yamaji, T. Kobayashi, Y. Kasahara, and H. Oya, 2009, Science, 323, 909--912. Solomon, S.C. and Head, J.W., 1980, Rev. Geophys., 18, 107--141. Trask, N.J., 1971, Geological Survey Research, U.S. Geol. Surv. Prof. Pap. 750-D, D138--D144. Watters, T.R., M.S. Robinson, M.E. Banks, T. Tran, and B.W. Denevi, 2012, Nature Geosci., 5, 181--185.

10 CFR 960.4-2-7 - Tectonics.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Tectonics. 960.4-2-7 Section 960.4-2-7 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Postclosure Guidelines § 960.4-2-7 Tectonics. (a) Qualifying condition. The site shall be located...

Alternative Conceptions of Plate Tectonics Held by Nonscience Undergraduates

ERIC Educational Resources Information Center

Clark, Scott K.; Libarkin, Julie C.; Kortz, Karen M.; Jordan, Sarah C.

2011-01-01

The theory of plate tectonics is the conceptual model through which most dynamic processes on Earth are understood. A solid understanding of the basic tenets of this theory is crucial in developing a scientifically literate public and future geoscientists. The size of plates and scale of tectonic processes are inherently unobservable,…

Earthquakes and plate tectonics

USGS Publications Warehouse

Spall, H.

1977-01-01

An explanation is to be found in plate tectonics, a concept which has revolutionized thinking in the Earth sciences in the last 10 years. The theory of plate tectonics combines many of the ideas about continental drift (originally proposed in 1912 by Alfred Wegener in Germany) and sea-floor spreading (suggested originally by Harry Hess of Princeton University). 

From past to current tectonics: Thematic issue dedicated to Jean-François Stéphan (1949-2013)

NASA Astrophysics Data System (ADS)

Manighetti, Isabelle

2016-01-01

This thematic issue of Comptes rendus Geoscience has been assembled to honor the memory of our late colleague and friend Jean-François Stéphan. Jean-François was a great scientist, specialized in tectonics, and a great colleague who devoted his time for his community. His work and actions deeply imprinted both the French and the International Earth Science communities. This volume brings together contributions of colleagues of Jean-François, who were also close friends or colleagues who knew and deeply appreciated him. Naturally, tectonics is the common theme of these contributions. Some of the papers presented here focus on tectonic questions and/or regions Jean-François worked on during his career; other papers present studies Jean-François motivated or encouraged in one way or another; other papers are simply tectonic studies he would have liked. Taken together, the nine papers of this thematic issue take the reader on a beautiful trip, from past to current tectonics.

Palaeomagnetic evidence for post-thrusting tectonic rotation in the Southeast Pyrenees, Spain

NASA Astrophysics Data System (ADS)

Keller, P.; Lowrie, W.; Gehring, A. U.

1994-12-01

The structural framework of the Southeast Pyrenees led to two conflicting interpretations—thrust tectonics vs. wrench tectonics—to explain the geometry of this mountain range. In the present study palaeomagnetic data are presented in an attempt to resolve this conflict. The data reveal different magnetisation directions that indicate tectonic rotations about vertical axes. By means of a regionally homogeneous pattern of rotation, three tectonic units could be distinguished in the Southeast Pyrenees. The Internal Unit in the north reveals no rotation since the Permian. The External Unit to the south shows anticlockwise rotation of 25°, younger than the Early Oligocene. The Pedraforca Unit, placed on the External Unit, shows 57° clockwise rotation which can be assigned to the Neogene. The anticlockwise rotation of the External Unit can be explained by differential compression during the last phase of Pyrenean thrusting, whereas the clockwise rotation of the Pedraforca Unit can be interpreted by post-thrusting tectonics. The rotation pattern of the Southeast Pyrenees provides evidence for both Cretaceous to Paleogene N-S compression and Neogene right-lateral wrench tectonics.

Venusian tectonics: Convective coupling to the lithosphere?

NASA Technical Reports Server (NTRS)

Phillips, R. J.

1987-01-01

The relationship between the dominant global heat loss mechanism and planetary size has motivated the search for tectonic style on Venus. Prior to the American and Soviet mapping missions of the past eight years, it was thought that terrestrial style plate tectonics was operative on Venus because this planet is approximately the size of the Earth and is conjectured to have about the same heat source content per unit mass. However, surface topography mapped by the altimeter of the Pioneer Venus spacecraft did not show any physiographic expression of terrestrial style spreading ridges, trenches, volcanic arcs or transform faults, although the horizontal resolution was questionable for detection of at least some of these features. The Venera 15 and 16 radar missions mapped the northern latitudes of Venus at 1 to 2 km resolution and showed that there are significant geographic areas of deformation seemingly created by large horizontal stresses. These same high resolution images show no evidence for plate tectonic features. Thus a fundamental problem for venusian tectonics is the origin of large horizontal stresses near the surface in the apparent absence of plate tectonics.

On the relative significance of lithospheric weakening mechanisms for sustained plate tectonics

NASA Astrophysics Data System (ADS)

Araceli Sanchez-Maes, Sophia

2018-01-01

Plate tectonics requires the bending of strong plates at subduction zones, which is difficult to achieve without a secondary weakening mechanism. Two classes of weakening mechanisms have been proposed for the generation of ongoing plate tectonics, distinguished by whether or not they require water. Here we show that the energy budget of global subduction zones offers a simple yet decisive test on their relative significance. Theoretical studies of mantle convection suggest bending dissipation to occupy only 10-20 % of total dissipation in the mantle, and our results indicate that the hydrous mechanism in the shallow part of plates is essential to satisfy the requirement. Thus, surface oceans are required for the long-term operation of plate tectonics on terrestrial worlds. Establishing this necessary and observable condition for sustained plate tectonics carries important implications for planetary habitability at large.

Global-scale tectonic patterns on Pluto

NASA Astrophysics Data System (ADS)

Matsuyama, I.; Keane, J. T.; Kamata, S.

2016-12-01

The New Horizons spacecraft revealed a global-scale tectonic pattern on the surface of Pluto which is presumably related to its formation and early evolution. Changes in the rotational and tidal potentials, expansion, and loading can generate stresses capable of producing global-scale tectonic patterns. The current alignment of Sputnik Planum with the tidal axis suggests a reorientation of Pluto relative to the rotation and tidal axes, or true polar wander. This reorientation can be driven by mass loading associated with Sputnik Planum. We developed a general theoretical formalism for the calculation of tectonic patterns due to a variety of process including true polar wander, loading, and expansion. The formalism is general enough to be applicable to non-axisymmetric loads. We illustrate that the observed global-scale tectonic pattern can be explained by stresses generated by true polar wander, Sputnik Planum loading, and expansion.

Plate Tectonics on Earth-like Planets: Implications for Habitability

NASA Astrophysics Data System (ADS)

Noack, L.; Breuer, D.

2011-12-01

Plate tectonics has been suggested to be essential for life (see e.g. [1]) due to the replenishment of nutrients and its role in the stabilization of the atmosphere temperature through the carbon-silicate cycle. Whether plate tectonics can prevail on a planet should depend on several factors, e.g. planetary mass, age of the planet, water content (at the surface and in the interior), surface temperature, mantle rheology, density variations in the mantle due to partial melting, and life itself by promoting erosion processes and perhaps even the production of continental rock [2]. In the present study, we have investigated how planetary mass, internal heating, surface temperature and water content in the mantle would factor for the probability of plate tectonics to occur on a planet. We allow the viscosity to be a function of pressure [3], an effect mostly neglected in previous discussions of plate tectonics on exoplanets [4, 5]. With the pressure-dependence of viscosity allowed for, the lower mantle may become too viscous in massive planets for convection to occur. When varying the planetary mass between 0.1 and 10 Earth masses, we find a maximum for the likelihood of plate tectonics to occur for planetary masses around a few Earth masses. For these masses the convective stresses acting at the base of the lithosphere are strongest and may become larger than the lithosphere yield strength. The optimum planetary mass varies slightly depending on the parameter values used (e.g. wet or dry rheology; initial mantle temperature). However, the peak in likelihood of plate tectonics remains roughly in the range of one to five Earth masses for reasonable parameter choices. Internal heating has a similar effect on the occurrence of plate tectonics as the planetary mass, i.e. there is a peak in the probability of plate tectonics depending on the internal heating rate. This result suggests that a planet may evolve as a consequence of radioactive decay into and out of the plate tectonics regime. References [1] Parnell, J. (2004): Plate tectonics, surface mineralogy, and the early evolution of life. Int. J. Astrobio. 3(2): 131-137. [2] Rosing, M.T.; D.K. Bird, N.H. Sleep, W. Glassley, and F. Albar (2006): The rise of continents - An essay on the geologic consequences of photosynthesis. Palaeogeography, Palaeoclimatology, Palaeoecology 232 (2006) 99-11. [3] Stamenkovic, V.; D. Breuer and T. Spohn (2011): Thermal and transport properties of mantle rock at high pressure: Applications to super-Earths. Submitted to Icarus. [4] Valencia, D., R.J. O'Connell and D.D. Sasselov (2007): Inevitability of plate tectonics on super-Earths. Astrophys. J. Let. 670(1): 45-48. [5] O'Neill, C. and A. Lenardic (2007). Geological consequences of super-sized Earths. GRL 34: 1-41.

Development of a New Analog Test System Capable of Modeling Tectonic Deformation Incorporating the Effects of Pore Fluid Pressure

NASA Astrophysics Data System (ADS)

Zhang, M.; Nakajima, H.; Takeda, M.; Aung, T. T.

2005-12-01

Understanding and predicting the tectonic deformation within geologic strata has been a very important research subject in many fields such as structural geology and petroleum geology. In recent years, such research has also become a fundamental necessity for the assessment of active fault migration, site selection for geological disposal of radioactive nuclear waste and exploration for methane hydrate. Although analog modeling techniques have played an important role in the elucidation of the tectonic deformation mechanisms, traditional approaches have typically used dry materials and ignored the effects of pore fluid pressure. In order for analog models to properly depict the tectonic deformation of the targeted, large-prototype system within a small laboratory-scale configuration, physical properties of the models, including geometry, force, and time, must be correctly scaled. Model materials representing brittle rock behavior require an internal friction identical to the prototype rock and virtually zero cohesion. Granular materials such as sand, glass beads, or steel beads of dry condition have been preferably used for this reason in addition to their availability and ease of handling. Modeling protocols for dry granular materials have been well established but such model tests cannot account for the pore fluid effects. Although the concept of effective stress has long been recognized and the role of pore-fluid pressure in tectonic deformation processes is evident, there have been few analog model studies that consider the effects of pore fluid movement. Some new applications require a thorough understanding of the coupled deformation and fluid flow processes within the strata. Taking the field of waste management as an example, deep geological disposal of radioactive waste has been thought to be an appropriate methodology for the safe isolation of the wastes from the human environment until the toxicity of the wastes decays to non-hazardous levels. For the deep geological disposal concept, besides containing the wastes with engineering methods such as the glassification of the radioactive wastes, the geological formation itself is expected to serve as a natural barrier that retards migration of radionuclides. To evaluate the long-term safety of deep geological disposal, a better understanding of the fate and transport of radionuclides in a geologically heterogeneous environment is necessary. To meet such requirements, a new analog test sandbox model system was developed. This model system allows the pore fluid flows to be controlled during the model tests and permits the study of flow and transport phenomena in the deformed heterogeneous model. One- or two-dimensional fluid flow is controlled using a side-wall piston. Deformation processes can be observed through a transparent front panel, and pore fluid movement can be also visualized using a color tracer. In this study, the scaling requirements for analog modeling, including pore water pressure, are discussed based on the theory of dimensional analysis, supplemented by data from a series of laboratory shear tests, and a detailed description of the model system. Preliminary experimental results are presented.

Basin analysis in the Southern Tethyan margin: Facies sequences, stratal pattern and subsidence history highlight extension-to-inversion processes in the Cretaceous Panormide carbonate platform (NW Sicily)

NASA Astrophysics Data System (ADS)

Basilone, Luca; Sulli, Attilio

2018-01-01

In the Mediterranean, the South-Tethys paleomargin experienced polyphased tectonic episodes and paleoenvironmental perturbations during Mesozoic time. The Cretaceous shallow-water carbonate successions of the Panormide platform, outcropping in the northern edge of the Palermo Mountains (NW Sicily), were studied by integrating facies and stratal pattern with backstripping analysis to recognize the tectonics vs. carbonate sedimentation interaction. The features of the Requienid limestone, including geometric configuration, facies sequence, lithological changes and significance of the top-unconformity, highlight that at the end of the Lower Cretaceous the carbonate platform was tectonically dismembered in various rotating fault-blocks. The variable trends of the subsidence curves testify to different responses, both uplift and downthrow, of various platform-blocks impacted by extensional tectonics. Physical stratigraphic and facies analysis of the Rudistid limestone highlight that during the Upper Cretaceous the previously carbonate platform faulted-blocks were subjected to vertical movements in the direction opposite to the displacement produced by the extensional tectonics, indicating a positive tectonic inversion. Comparisons with other sectors of the Southern Tethyan and Adria paleomargins indicate that during the Cretaceous these areas underwent the same extensional and compressional stages occurring in the Panormide carbonate platform, suggesting a regional scale significance, in time and kinematics, for these tectonic events.

Late Tharsis tectonic activity and implications for Early Mars

NASA Astrophysics Data System (ADS)

Bouley, S.; Baratoux, D.; Paulien, N.; Missenard, Y.; Saint-Bezar, B.

2017-12-01

Constraining the timing of Tharsis volcanism is critical to understanding the planet's evolution including its climate, surface environment and mantle dynamics. The tectonic history of the Tharsis bulge was previously documented from the distribution and ages of related tectonic features [1]. Here we revisit the ages of 7493 Tharsis-related tectonic features based on their relationship with stratigraphic units defined in the new geological map [2]. Conversely to previous tectonic mapping [1], which suggested that Tharsis growth was nearly achieved during the Noachian, we find a protracted growth of Tharsis during the Hesperian. Faulting at Tempe Terra, Claritas and Coracis Fossae and Thaumasia Planum confirms that tectonic deformation started during the Noachian. Accumulated tectonic deformation was maximum in the Early Hesperian for compressional strain (Solis, Lunae and Ascuris Planum) and extended over time from Noachian to Amazonian for extensional strain (Noctis Labyrinthus and Fossae, Sinai Planum and Tractus, Ulysses and Fortuna fossae, Alba Patera). This new scenario is consistent with a protracted growth of Tharsis dome during the Hesperian and with the timing a large Tharsis-driven true polar wander post-dating the incision of Late Noachian/Hesperian valley networks[3]. References:[1] Anderson et al. JGR-Planets 106, E9, 20,563-20,585 (2001).[2] Tanaka, K.L. et al. Geologic map of Mars (2014). [3] Bouley et al. Nature doi:10.1038 (2016)

Spreading continents kick-started plate tectonics.

PubMed

Rey, Patrice F; Coltice, Nicolas; Flament, Nicolas

2014-09-18

Stresses acting on cold, thick and negatively buoyant oceanic lithosphere are thought to be crucial to the initiation of subduction and the operation of plate tectonics, which characterizes the present-day geodynamics of the Earth. Because the Earth's interior was hotter in the Archaean eon, the oceanic crust may have been thicker, thereby making the oceanic lithosphere more buoyant than at present, and whether subduction and plate tectonics occurred during this time is ambiguous, both in the geological record and in geodynamic models. Here we show that because the oceanic crust was thick and buoyant, early continents may have produced intra-lithospheric gravitational stresses large enough to drive their gravitational spreading, to initiate subduction at their margins and to trigger episodes of subduction. Our model predicts the co-occurrence of deep to progressively shallower mafic volcanics and arc magmatism within continents in a self-consistent geodynamic framework, explaining the enigmatic multimodal volcanism and tectonic record of Archaean cratons. Moreover, our model predicts a petrological stratification and tectonic structure of the sub-continental lithospheric mantle, two predictions that are consistent with xenolith and seismic studies, respectively, and consistent with the existence of a mid-lithospheric seismic discontinuity. The slow gravitational collapse of early continents could have kick-started transient episodes of plate tectonics until, as the Earth's interior cooled and oceanic lithosphere became heavier, plate tectonics became self-sustaining.

Tectonic sequence stratigraphy, Early Permian Dry Mountain trough, east-central Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snyder, W.S.; Gallegos, D.M.; Spinosa, C.

1991-06-01

The Early Permian Dry Mountain trough (DMT) of east-central Nevada is one of several tectonic basins and associated uplifts that developed along the continenetal margin during the latest Pennsylvanian-Early Permian Dry Mountain tectonic phase. The sequence stratigraphy reflects a combination of eustatic sea level changes and tectonic uplift or subsidence. Fewer than one to only a few million years separate the development of sequence boundaries within the DMT. At this scale, differences among published eustasy curves preclude their use as definitive tools to identify eustatically controlled sequence boundaries. Nevertheless, available data indicate several pulses of tectonism affected sedimentation within themore » DMT. The authors are attempting to develop criteria to distinguish tectonic from eustatic sequence boundaries. Detailed biostratigraphic data are required to provide an independent check on the correlation of sequence boundaries between measured sections. For example, the same age boundary may reflect tectonic uplift in one part of the basin and subsidence in another. The uplift may or may not result in subaerial exposure and erosion. For those boundaries that do not result from subaerial exposure, lithofacies and biofacies analyses are required to infer relative uplift (water depth decrease) or subsidence (water depth increase). There are inherent resolution limitations in both the paleontologic and sedimentologic methodologies. These limitations, combined with those of eustasy curves, dictate the preliminary nature of their results.« less

Tissue engineering in dentistry.

PubMed

Abou Neel, Ensanya Ali; Chrzanowski, Wojciech; Salih, Vehid M; Kim, Hae-Won; Knowles, Jonathan C

2014-08-01

of this review is to inform practitioners with the most updated information on tissue engineering and its potential applications in dentistry. The authors used "PUBMED" to find relevant literature written in English and published from the beginning of tissue engineering until today. A combination of keywords was used as the search terms e.g., "tissue engineering", "approaches", "strategies" "dentistry", "dental stem cells", "dentino-pulp complex", "guided tissue regeneration", "whole tooth", "TMJ", "condyle", "salivary glands", and "oral mucosa". Abstracts and full text articles were used to identify causes of craniofacial tissue loss, different approaches for craniofacial reconstructions, how the tissue engineering emerges, different strategies of tissue engineering, biomaterials employed for this purpose, the major attempts to engineer different dental structures, finally challenges and future of tissue engineering in dentistry. Only those articles that dealt with the tissue engineering in dentistry were selected. There have been a recent surge in guided tissue engineering methods to manage periodontal diseases beyond the traditional approaches. However, the predictable reconstruction of the innate organisation and function of whole teeth as well as their periodontal structures remains challenging. Despite some limited progress and minor successes, there remain distinct and important challenges in the development of reproducible and clinically safe approaches for oral tissue repair and regeneration. Clearly, there is a convincing body of evidence which confirms the need for this type of treatment, and public health data worldwide indicates a more than adequate patient resource. The future of these therapies involving more biological approaches and the use of dental tissue stem cells is promising and advancing. Also there may be a significant interest of their application and wider potential to treat disorders beyond the craniofacial region. Considering the interests of the patients who could possibly be helped by applying stem cell-based therapies should be carefully assessed against current ethical concerns regarding the moral status of the early embryo. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Workshop on the Tectonic Evolution of Greenstone Belts

NASA Technical Reports Server (NTRS)

1986-01-01

The Workshop on the Tectonic Evolution of Greenstone Belts, which is part of the Universities Space Research Association, Lunar and Planetary Institute, of Houston, Texas, met there on Jan. 16-18, 1986. A number of plate tectonic hypotheses have been proposed to explain the origin of Archean and Phanerozoic greenstone/ophiolite terranes. These hypotheses are explored in the abstracts.

Strain transformation between tectonic extrusion and crustal thickening in the growth of the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Liu, M.; Li, Y.; Sun, Y.; Shen, X.

2017-12-01

The Indo-Eurasian continental collision since 50 Ma has thickened the crust to raise the Himalayan-Tibetan Plateau and driven lateral extrusion of Asian lithospheric blocks to affect Cenozoic tectonics in central and east Asia. The relative roles of crustal thickening and tectonic extrusion, and the strain partitioning between them over time and space, remain controversial. We have analyzed the strain rates using GPS velocities, and correlated the results with vertical motion derived from precise leveling. We found that tectonic extrusion largely transforms to crustal thickening near the margins of the Tibetan Plateau. Near the NW margin of the Tibetan Plateau, the shear stain transforms to compressive strain, consistent with neotectonic studies that indicate crustal shortening and uplift. Around the SE margin, shear stain largely terminates in the southern Yunnan province of China. The present-day crustal motion in SE Tibetan Plateau can be well explained by gravitational spreading without invoking plate-edge push as envisioned in the tectonic extrusion model. Using data collected from local seismic arrays, we derived receiver functions to image the lithospheric structures across the Tibetan Plateau and the Alashan block to its north and the Ordos block to its east. Our results indicate that the mantle lithosphere of these bounding Asian blocks has not been reworked by Tibetan tectonics; instead they have acted as restrictive walls to the growing Tibetan Plateau. Our finite element modeling shows that crustal deformation along the margins of the Tibetan Plateau are consistent with the notion that the east- and southeastward extrusion of the Tibetan lithosphere is largely confined to the Tibetan Plateau because of the restrictive bounding blocks of the Asian lithosphere. Thus the tectonic impact of the Indo-Eurasian collision on the Cenozoic Asian tectonics may not be as extensive as previously thought.

The Role of Plate Tectonic-Climate Coupling and Exposed Land Area in the Development of Habitable Climates on Rocky Planets

NASA Astrophysics Data System (ADS)

Foley, Bradford J.

2015-10-01

The long-term carbon cycle is vital for maintaining liquid water oceans on rocky planets due to the negative climate feedbacks involved in silicate weathering. Plate tectonics plays a crucial role in driving the long-term carbon cycle because it is responsible for CO2 degassing at ridges and arcs, the return of CO2 to the mantle through subduction, and supplying fresh, weatherable rock to the surface via uplift and orogeny. However, the presence of plate tectonics itself may depend on climate according to recent geodynamical studies showing that cool surface temperatures are important for maintaining vigorous plate tectonics. Using a simple carbon cycle model, I show that the negative climate feedbacks inherent in the long-term carbon cycle are uninhibited by climate's effect on plate tectonics. Furthermore, initial atmospheric CO2 conditions do not impact the final climate state reached when the carbon cycle comes to equilibrium, as long as liquid water is present and silicate weathering can occur. Thus an initially hot, CO2 rich atmosphere does not prevent the development of a temperate climate and plate tectonics on a planet. However, globally supply limited weathering does prevent the development of temperate climates on planets with small subaerial land areas and large total CO2 budgets because supply limited weathering lacks stabilizing climate feedbacks. Planets in the supply limited regime may become inhospitable for life and could experience significant water loss. Supply limited weathering is less likely on plate tectonic planets because plate tectonics promotes high erosion rates and thus a greater supply of bedrock to the surface.

Ogaden Basin subsidence history: Another key to the Red Sea-Gulf of Aden tectonic puzzle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pigott, J.D.; Neese, D.; Carsten, G.

1995-08-01

Previous work has attempted to understand the tectonic evolution of the Red Sea-Gulf of Aden region through a focus upon plate kinematics and reconstruction of plate interactions in a two dimensional sense. A significant complement to the three dimensional puzzle can be derived from a critical examination of the vertical component, tectonic subsidence analysis. By removing the isostatic contributions of sediment loading and unloading, and fluctuations in sea level, the remaining thermal-mechanical contribution to a basin`s subsidence can be determined. Such an analysis of several Ogaden Basin wells reveals multiple pulses of tectonic subsidence and uplift which correspond to far-fieldmore » tectonic activities in the Red Sea and Gulf of Aden. One of the more dramatic is a Jurassic tectonic pulse circa 145-130 m.a., and a later extensional event which correlates to a major subsidence event ubiquitous through-out the Gulf of Aden, related to Gondwana Land breakup activities. Tectonic uplift during the Tertiary coincides with early Red Sea rifting episodes. Such activities suggest the Ogaden Basin has been a relatively stable East African cratonic basin, but with heating-extension events related to nearby plate interactions. In terms of hydrocarbon generation, the use of steady state present day geothermal gradients, coupled with subsidence analysis shows that potential Paleozoic and Mesozoic source rocks initiated generation as early as the Jurassic. The generating potential of Paleozoic source rocks would only be exacerbated by later heating events. Furthermore, cooling and tectonic uplift during the Tertiary would tend to arrest on-going hydrocarbon generation for Jurassic source rocks in the Ogaden area.« less

Earth Science Keyword Stewardship: Access and Management through NASA's Global Change Master Directory (GCMD) Keyword Management System (KMS)

NASA Astrophysics Data System (ADS)

Stevens, T.; Olsen, L. M.; Ritz, S.; Morahan, M.; Aleman, A.; Cepero, L.; Gokey, C.; Holland, M.; Cordova, R.; Areu, S.; Cherry, T.; Tran-Ho, H.

2012-12-01

Discovering Earth science data can be complex if the catalog holding the data lacks structure. Controlled keyword vocabularies within metadata catalogues can improve data discovery. NASA's Global Change Master Directory's (GCMD) Keyword Management System (KMS) is a recently released a RESTful web service for managing and providing access to controlled keywords (science keywords, service keywords, platforms, instruments, providers, locations, projects, data resolution, etc.). The KMS introduces a completely new paradigm for the use and management of the keywords and allows access to these keywords as SKOS Concepts (RDF), OWL, standard XML, and CSV. A universally unique identifier (UUID) is automatically assigned to each keyword, which uniquely identifies each concept and its associated information. A component of the KMS is the keyword manager, an internal tool that allows GCMD science coordinators to manage concepts. This includes adding, modifying, and deleting broader, narrower, or related concepts and associated definitions. The controlled keyword vocabulary represents over 20 years of effort and collaboration with the Earth science community. The maintenance, stability, and ongoing vigilance in maintaining mutually exclusive and parallel keyword lists is important for a "normalized" search and discovery, and provides a unique advantage for the science community. Modifications and additions are made based on community suggestions and internal review. To help maintain keyword integrity, science keyword rules and procedures for modification of keywords were developed. This poster will highlight the use of the KMS as a beneficial service for the stewardship and access of the GCMD keywords. Users will learn how to access the KMS and utilize the keywords. Best practices for managing an extensive keyword hierarchy will also be discussed. Participants will learn the process for making keyword suggestions, which subsequently help in building a controlled keyword vocabulary to improve earth science data discovery and access.

Probabilistic estimation of long-term volcanic hazard under evolving tectonic conditions in a 1 Ma timeframe

NASA Astrophysics Data System (ADS)

Jaquet, O.; Lantuéjoul, C.; Goto, J.

2017-10-01

Risk assessments in relation to the siting of potential deep geological repositories for radioactive wastes demand the estimation of long-term tectonic hazards such as volcanicity and rock deformation. Owing to their tectonic situation, such evaluations concern many industrial regions around the world. For sites near volcanically active regions, a prevailing source of uncertainty is related to volcanic hazard. For specific situations, in particular in relation to geological repository siting, the requirements for the assessment of volcanic and tectonic hazards have to be expanded to 1 million years. At such time scales, tectonic changes are likely to influence volcanic hazard and therefore a particular stochastic model needs to be developed for the estimation of volcanic hazard. The concepts and theoretical basis of the proposed model are given and a methodological illustration is provided using data from the Tohoku region of Japan.

MEVTV Workshop on Early Tectonic and Volcanic Evolution of Mars

NASA Technical Reports Server (NTRS)

Frey, H. (Editor)

1988-01-01

Although not ignored, the problems of the early tectonic and volcanic evolution of Mars have generally received less attention than those later in the evolution of the planet. Specifically, much attention was devoted to the evolution of the Tharsis region of Mars and to the planet itself at the time following the establishment of this major tectonic and volcanic province. By contrast, little attention was directed at fundamental questions, such as the conditions that led to the development of Tharsis and the cause of the basic fundamental dichotomy of the Martian crust. It was to address these and related questions of the earliest evolution of Mars that a workshop was organized under the auspices of the Mars: Evolution of Volcanism, Tectonism, and Volatiles (MEVTV) Program. Four sessions were held: crustal dichotomy; crustal differentiation/volcanism; Tharsis, Elysium, and Valles Marineris; and ridges and fault tectonics.

The origin of strike-slip tectonics in continental rifts

NASA Astrophysics Data System (ADS)

Ebinger, C. J.; Pagli, C.; Yun, S. H.; Keir, D.; Wang, H.

2016-12-01

Although continental rifts are zones of lithospheric extension, strike-slip tectonics is also accommodated within rifts and its origin remains controversial. Here we present a combined analysis of recent seismicity, InSAR and GPS derived strain maps to reveal that the plate motion in Afar is accommodated primarily by extensional tectonics in all rift arms and lacks evidences of regional scale bookshelf tectonics. However in the rifts of central Afar we identify crustal extension and normal faulting in the central part of the rifts but strike-slip earthquakes at the rift tips. We investigate if strike-slip can be the result of Coulomb stress changes induced by recent dyking but models do not explain these earthquakes. Instead we explain strike-slips as shearing at the tips of a broad zone of spreading where extension terminates against unstretched lithosphere. Our results demonstrate that plate spreading can develop both strike-slip and extensional tectonics in the same rifts.

Heat-pipe Earth.

PubMed

Moore, William B; Webb, A Alexander G

2013-09-26

The heat transport and lithospheric dynamics of early Earth are currently explained by plate tectonic and vertical tectonic models, but these do not offer a global synthesis consistent with the geologic record. Here we use numerical simulations and comparison with the geologic record to explore a heat-pipe model in which volcanism dominates surface heat transport. These simulations indicate that a cold and thick lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downwards. Declining heat sources over time led to an abrupt transition to plate tectonics. Consistent with model predictions, the geologic record shows rapid volcanic resurfacing, contractional deformation, a low geothermal gradient across the bulk of the lithosphere and a rapid decrease in heat-pipe volcanism after initiation of plate tectonics. The heat-pipe Earth model therefore offers a coherent geodynamic framework in which to explore the evolution of our planet before the onset of plate tectonics.

The interior of Venus and Tectonic implications

NASA Technical Reports Server (NTRS)

Phillips, R. J.; Malin, M. C.

1983-01-01

It is noted in the present consideration of the Venus lithosphere and its implications for plate tectonics that the major linear elevated regions of Venus, which are associated with Beta Regio and Aphrodite Terra, do not seem to have the shape required for sure interpretation as the divergent plate boundaries of seafloor spreading. Such tectonics instead appear to be confined to the median plains, and may not be resolvable in the Pioneer Venus altimetry data. The ratios of gravity anomalies to topographic heights indicate that surface load compensation occurs at depths greater than about 100 km under the western Aphrodite Terra and 400 km under Beta Regio, with at least some of this compensation probably being maintained by mantle convection. It is also found that the shape of Venus's hypsogram is very different from the ocean mode of the earth's hypsogram, and it is proposed that Venus tectonics resemble intraplate, basin-and-swell tectonics on earth.

Lentivirus-Mediated knockdown of tectonic family member 1 inhibits medulloblastoma cell proliferation

PubMed Central

Jing, Junjie; Wang, Chengfeng; Liang, Qinchuan; Zhao, Yang; Zhao, Qingshuang; Wang, Shousen; Ma, Jie

2015-01-01

Tectonic family member 1 (TCTN1) encodes a member of the tectonic family which are evolutionarily conserved secreted and transmembrane proteins, involving in a diverse variety of developmental processes. It has been demonstrated that tectonics expressed in regions that participate in Hedgehog (Hh) signaling during mouse embryonic development and was imperative for Hh-mediated patterning of the ventral neural tube. However, the expression and regulation of tectonics in human tumor is still not clear. In this study, shRNA-expressing lentivirus was constructed to knockdown TCTN1 in medulloblastoma cell line Daoy. The results showed that knockdown of TCTN1 inhibited cell proliferation and colony formation in Daoy cell line, also caused cell cycle arrest at the G2/M boundary. Taken all together, our data suggest that TCTN1 might play an important role in the progression of medulloblastoma. PMID:26550235

Towards Identifying and Reducing the Bias of Disease Information Extracted from Search Engine Data

PubMed Central

Huang, Da-Cang; Wang, Jin-Feng; Huang, Ji-Xia; Sui, Daniel Z.; Zhang, Hong-Yan; Hu, Mao-Gui; Xu, Cheng-Dong

2016-01-01

The estimation of disease prevalence in online search engine data (e.g., Google Flu Trends (GFT)) has received a considerable amount of scholarly and public attention in recent years. While the utility of search engine data for disease surveillance has been demonstrated, the scientific community still seeks ways to identify and reduce biases that are embedded in search engine data. The primary goal of this study is to explore new ways of improving the accuracy of disease prevalence estimations by combining traditional disease data with search engine data. A novel method, Biased Sentinel Hospital-based Area Disease Estimation (B-SHADE), is introduced to reduce search engine data bias from a geographical perspective. To monitor search trends on Hand, Foot and Mouth Disease (HFMD) in Guangdong Province, China, we tested our approach by selecting 11 keywords from the Baidu index platform, a Chinese big data analyst similar to GFT. The correlation between the number of real cases and the composite index was 0.8. After decomposing the composite index at the city level, we found that only 10 cities presented a correlation of close to 0.8 or higher. These cities were found to be more stable with respect to search volume, and they were selected as sample cities in order to estimate the search volume of the entire province. After the estimation, the correlation improved from 0.8 to 0.864. After fitting the revised search volume with historical cases, the mean absolute error was 11.19% lower than it was when the original search volume and historical cases were combined. To our knowledge, this is the first study to reduce search engine data bias levels through the use of rigorous spatial sampling strategies. PMID:27271698

Towards Identifying and Reducing the Bias of Disease Information Extracted from Search Engine Data.

PubMed

Huang, Da-Cang; Wang, Jin-Feng; Huang, Ji-Xia; Sui, Daniel Z; Zhang, Hong-Yan; Hu, Mao-Gui; Xu, Cheng-Dong

2016-06-01

The estimation of disease prevalence in online search engine data (e.g., Google Flu Trends (GFT)) has received a considerable amount of scholarly and public attention in recent years. While the utility of search engine data for disease surveillance has been demonstrated, the scientific community still seeks ways to identify and reduce biases that are embedded in search engine data. The primary goal of this study is to explore new ways of improving the accuracy of disease prevalence estimations by combining traditional disease data with search engine data. A novel method, Biased Sentinel Hospital-based Area Disease Estimation (B-SHADE), is introduced to reduce search engine data bias from a geographical perspective. To monitor search trends on Hand, Foot and Mouth Disease (HFMD) in Guangdong Province, China, we tested our approach by selecting 11 keywords from the Baidu index platform, a Chinese big data analyst similar to GFT. The correlation between the number of real cases and the composite index was 0.8. After decomposing the composite index at the city level, we found that only 10 cities presented a correlation of close to 0.8 or higher. These cities were found to be more stable with respect to search volume, and they were selected as sample cities in order to estimate the search volume of the entire province. After the estimation, the correlation improved from 0.8 to 0.864. After fitting the revised search volume with historical cases, the mean absolute error was 11.19% lower than it was when the original search volume and historical cases were combined. To our knowledge, this is the first study to reduce search engine data bias levels through the use of rigorous spatial sampling strategies.

HST Keyword Dictionary

NASA Astrophysics Data System (ADS)

Swade, D. A.; Gardner, L.; Hopkins, E.; Kimball, T.; Lezon, K.; Rose, J.; Shiao, B.

STScI has undertaken a project to place all HST keyword information in one source, the keyword database, and to provide a mechanism for making this keyword information accessible to all HST users, the keyword dictionary, which is a WWW interface to the keyword database.

Regional geology and tectonics

USGS Publications Warehouse

Nokleberg, Warren J.; Bundtzen, Thomas K.; Nokleberg, Warren J.; Price, Raymond A.; Scholl, David W.; Stone, David B.

2017-01-01

This chapter describes the regional geology and tectonic origins of the major geologic units for the Northern Cordillera. The goals of the chapter are to: (1) provide a summary and regional overview of this vast region that contains a complicated geologic history; and (2) describe the major geologic units and tectonic events that cover a broad geologic time span from the Proterozoic to the Holocene (Recent).

High-Resolution Regional Phase Attenuation Models of the Iranian Plateau and Surrounding Regions

DTIC Science & Technology

2014-03-03

1 2.2. Tectonic and Geophysical Setting ..........................................................................2 2.3...superimposed with the major tectonic features across the Middle East. The major faults are depicted with black solid lines. The main continental boundary fault...zones and tectonic settings are abbreviated on the map and described here. The red triangles present the location of quaternary volcanoes. The dashed

Hot spot abundance, ridge subduction and the evolution of greenstone belts

NASA Technical Reports Server (NTRS)

Abbott, D.; Hoffman, S.

1986-01-01

A number of plate tectonic hypotheses have been proposed to explain the origin of Archaean and Phanerozoic greenstone/ophiolite terranes. In these models, ophiolites or greenstone belts represent the remnants of one or more of the following: island arcs, rifted continental margins, oceanic crustal sections, and hot spot volcanic products. If plate tectonics has been active since the creation of the Earth, it is logical to suppose that the same types of tectonic processes which form present day ophiolites also formed Archaean greenstone belts. However, the relative importance of the various tectonic processes may well have been different and are discussed.

Geomorphology and Tectonics at the Intersection of Silurian and Death Valleys, Southern California - 2005 Guidebook Pacific Cell Friends of the Pleistocene

USGS Publications Warehouse

Miller, David M.; Valin, Zenon C.

2007-01-01

This publication describes results from new regional and detailed surficial geologic mapping, combined with geomorphologic, geochronologic, and tectonic studies, in Silurian Valley and Death Valley, California. The studies address a long-standing problem, the tectonic and geomorphic evolution of the intersection between three regional tectonic provinces: the eastern California shear zone, the Basin and Range region of southern Nevada and adjacent California, and the eastern Mojave Desert region. The chapters represent work presented on the 2005 Friends of the Pleistocene field trip and meeting as well as the field trip road log.

On volcanism and thermal tectonics on one-plate planets

NASA Technical Reports Server (NTRS)

Solomon, S. C.

1978-01-01

For planets with a single global lithospheric shell or 'plate', the thermal evolution of the interior affects the surface geologic history through volumetric expansion and the resultant thermal stress. Interior warming of such planets gives rise to extensional tectonics and a lithospheric stress system conductive to widespread volcanism. Interior cooling leads to compressional tectonics and lithospheric stresses that act to shut off surface volcanism. On the basis of observed surface tectonics, it is concluded that the age of peak planetary volume, the degree of early heating, and the age of youngest major volcanism on the one-plate terrestrial planets likely decrease in the order Mercury, Moon, Mars.

Mantle convection and plate tectonics: toward an integrated physical and chemical theory

PubMed

Tackley

2000-06-16

Plate tectonics and convection of the solid, rocky mantle are responsible for transporting heat out of Earth. However, the physics of plate tectonics is poorly understood; other planets do not exhibit it. Recent seismic evidence for convection and mixing throughout the mantle seems at odds with the chemical composition of erupted magmas requiring the presence of several chemically distinct reservoirs within the mantle. There has been rapid progress on these two problems, with the emergence of the first self-consistent models of plate tectonics and mantle convection, along with new geochemical models that may be consistent with seismic and dynamical constraints on mantle structure.

Late cretaceous extensional tectonics and associated igneous activity on the northern margin of the Gulf of Mexico Basin

NASA Technical Reports Server (NTRS)

Bowen, R. L.; Sundeen, D. A.

1985-01-01

Major, dominantly compressional, orogenic episodes (Taconic, Acadian, Alleghenian) affected eastern North America during the Paleozoic. During the Mesozoic, in contrast, this same region was principally affected by epeirogenic and extensional tectonism; one episode of comparatively more intense tectonic activity involving extensive faulting, uplift, sedimentation, intrusion and effusion produced the Newark Series of eposits and fault block phenomena. This event, termed the Palisades Disturbance, took place during the Late Triassic - Earliest Jurassic. The authors document a comparable extensional tectonic-igneous event occurring during the Late Cretaceous (Early Gulfian; Cenomanian-Santonian) along the southern margin of the cratonic platform from Arkansas to Georgia.

Tectonic controls upon Kaveri River drainage, cratonic Peninsular India: Inferences from longitudinal profiles, morphotectonic indices, hanging valleys and fluvial records

NASA Astrophysics Data System (ADS)

Kale, Vishwas S.; Sengupta, Somasis; Achyuthan, Hema; Jaiswal, Manoj K.

2014-12-01

The Indian Peninsula is generally considered as a tectonically stable region, where ancient rocks, rivers and land surfaces predominate. In some parts of this ancient landscape, however, the role of tectonic landsculpting is strongly indicated by the presence of youthful topography and historical seismic activity. The present study is primarily focused on the middle domain of the Kaveri River, which displays such youthful features. The tectonic controls on this cratonic river were evaluated on the basis of the investigations of the longitudinal profiles, morphotectonic indices of active tectonics, and fluvial records. The presence of steep channel gradients, prominent knickpoints, hanging valleys, narrow bedrock gorges, and channel-in-channel morphology imply rapid erosion rates in the middle domain of the basin in response to active deformation, particularly in the reach defined by two major active faults - the Kollegal-Sivasamudram Fault and the Mekedatu Fault. Further, considering the remarkably low modern and long-term denudation rates and OSL ages of the alluvial deposits (30-40 ka), the tectonically-driven rejuvenation does not appear to be geologically recent as postulated by earlier workers.

Episodic Cenozoic volcanism and tectonism in the Andes of Peru

USGS Publications Warehouse

Noble, D.C.; McKee, E.H.; Farrar, E.; Petersen, U.

1974-01-01

Radiometric and geologic information indicate a complex history of Cenozoic volcanism and tectonism in the central Andes. K-Ar ages on silicic pyroclastic rocks demonstrate major volcanic activity in central and southern Peru, northern Chile, and adjacent areas during the Early and Middle Miocene, and provide additional evidence for volcanism during the Late Eocene. A provisional outline of tectonic and volcanic events in the Peruvian Andes during the Cenozoic includes: one or more pulses of igneous activity and intense deformation during the Paleocene and Eocene; a period of quiescence, lasting most of Oligocene time; reinception of tectonism and volcanism at the beginning of the Miocene; and a major pulse of deformation in the Middle Miocene accompanied and followed through the Pliocene by intense volcanism and plutonism. Reinception of igneous activity and tectonism at about the Oligocene-Miocene boundary, a feature recognized in other circum-Pacific regions, may reflect an increase in the rate of rotation of the Pacific plate relative to fixed or quasifixed mantle coordinates. Middle Miocene tectonism and latest Tertiary volcanism correlates with and probably is genetically related to the beginning of very rapid spreading at the East Pacific Rise. ?? 1974.

Geochronologic evidence for Late Cretaceous and Miocene tectonism in northern New England

NASA Astrophysics Data System (ADS)

Amidon, W. H.; Barr, M.; Walcott, C.; Kylander-Clark, A. R.

2017-12-01

The persistence of mountainous relief in the northeastern U.S. suggests post-rift tectonic rejuvenation has occurred, although specific mechanisms and timing have been difficult to identify. Here we present direct evidence for significant tectonism in New Hampshire and Vermont during the Late-Cretaceous ( 85-65 Ma) and Miocene periods ( 20-5 Ma). Low temperature thermochronology from a drill core in the White Mountains of New Hampshire suggests 2-3 km of accelerated exhumation during the Late Cretaceous. This exhumation is synchronous with compressional thrusting and rapid exhumation on many other Atlantic margins and also with a change in spreading direction in the Atlantic from 85-65 Ma. Recently obtained U-Pb ages of vein calcite from faults and fractures in the Champlain Valley of New York and Vermont suggest significant brittle fracturing occurred during the Late Cretaceous and also during the Miocene. Although many questions remain, this evidence points to tectonic rejuvenation by lateral tectonic stresses in the latest Cretaceous and possibly in the Miocene. The Late Cretaceous seems to have been a particularly significant tectonic episode in northern New England and elsewhere in the circum-Atlantic region.

Shell Tectonics: A Mechanical Model for Strike-slip Displacement on Europa

NASA Technical Reports Server (NTRS)

Rhoden, Alyssa Rose; Wurman, Gilead; Huff, Eric M.; Manga, Michael; Hurford, Terry A.

2012-01-01

We introduce a new mechanical model for producing tidally-driven strike-slip displacement along preexisting faults on Europa, which we call shell tectonics. This model differs from previous models of strike-slip on icy satellites by incorporating a Coulomb failure criterion, approximating a viscoelastic rheology, determining the slip direction based on the gradient of the tidal shear stress rather than its sign, and quantitatively determining the net offset over many orbits. This model allows us to predict the direction of net displacement along faults and determine relative accumulation rate of displacement. To test the shell tectonics model, we generate global predictions of slip direction and compare them with the observed global pattern of strike-slip displacement on Europa in which left-lateral faults dominate far north of the equator, right-lateral faults dominate in the far south, and near-equatorial regions display a mixture of both types of faults. The shell tectonics model reproduces this global pattern. Incorporating a small obliquity into calculations of tidal stresses, which are used as inputs to the shell tectonics model, can also explain regional differences in strike-slip fault populations. We also discuss implications for fault azimuths, fault depth, and Europa's tectonic history.

Iapetus: Tectonic structure and geologic history

NASA Technical Reports Server (NTRS)

Croft, Steven K.

1991-01-01

Many papers have been written about the surface of Iapetus, but most of these have discussed either the nature of the strongly contrasting light and dark materials or the cratering record. Little has been said about other geologic features on Iapetus, such as tectonic structures, which would provide constraints on Iapetus' thermal history. Most references have suggested that there is no conclusive evidence for any tectonic activity, even when thermal history studies indicate that there should be. However, a new study of Iapetus' surface involving the use of stereo pairs, an extensive tectonic network has been recognized. A few new observations concerning the craters and dark material were also made. Thus the geology and geologic history of Iapetus can be more fully outlined than before. The tectonic network is shown along with prominent craters and part of the dark material in the geologic/tectonic sketch map. The topology of crater rims and scarps are quite apparent and recognizable in the different image pairs. The heights and slopes of various features given are based on comparison with the depths of craters 50 to 100 km in diameter, which are assumed to have the same depths as craters of similar diameter on Rhea and Titania.

A transparent and data-driven global tectonic regionalization model for seismic hazard assessment

NASA Astrophysics Data System (ADS)

Chen, Yen-Shin; Weatherill, Graeme; Pagani, Marco; Cotton, Fabrice

2018-05-01

A key concept that is common to many assumptions inherent within seismic hazard assessment is that of tectonic similarity. This recognizes that certain regions of the globe may display similar geophysical characteristics, such as in the attenuation of seismic waves, the magnitude scaling properties of seismogenic sources or the seismic coupling of the lithosphere. Previous attempts at tectonic regionalization, particularly within a seismic hazard assessment context, have often been based on expert judgements; in most of these cases, the process for delineating tectonic regions is neither reproducible nor consistent from location to location. In this work, the regionalization process is implemented in a scheme that is reproducible, comprehensible from a geophysical rationale, and revisable when new relevant data are published. A spatial classification-scheme is developed based on fuzzy logic, enabling the quantification of concepts that are approximate rather than precise. Using the proposed methodology, we obtain a transparent and data-driven global tectonic regionalization model for seismic hazard applications as well as the subjective probabilities (e.g. degree of being active/degree of being cratonic) that indicate the degree to which a site belongs in a tectonic category.

The Effect of a Tectonic Stress Field on Coal and Gas Outbursts

PubMed Central

An, Fenghua; Cheng, Yuanping

2014-01-01

Coal and gas outbursts have always been a serious threat to the safe and efficient mining of coal resources. Ground stress (especially the tectonic stress) has a notable effect on the occurrence and distribution of outbursts in the field practice. A numerical model considering the effect of coal gas was established to analyze the outburst danger from the perspective of stress conditions. To evaluate the outburst tendency, the potential energy of yielded coal mass accumulated during an outburst initiation was studied. The results showed that the gas pressure and the strength reduction from the adsorbed gas aggravated the coal mass failure and the ground stress altered by tectonics would affect the plastic zone distribution. To demonstrate the outburst tendency, the ratio of potential energy for the outburst initiation and the energy consumption was used. Increase of coal gas and tectonic stress could enhance the potential energy accumulation ratio, meaning larger outburst tendency. The component of potential energy for outburst initiation indicated that the proportion of elastic energy was increased due to tectonic stress. The elastic energy increase is deduced as the cause for a greater outburst danger in a tectonic area from the perspective of stress conditions. PMID:24991648

Venus as a laboratory for studying planetary surface, interior, and atmospheric evolution

NASA Astrophysics Data System (ADS)

Smrekar, S. E.; Hensley, S.; Helbert, J.

2013-12-01

As Earth's twin, Venus offers a laboratory for understanding what makes our home planet unique in our solar system. The Decadal Survey points to the role of Venus in answering questions such as the supply of water and its role in atmospheric evolution, its availability to support life, and the role of geology and dynamics in controlling volatiles and climate. On Earth, the mechanism of plate tectonics drives the deformation and volcanism that allows volatiles to escape from the interior to the atmosphere and be recycled into the interior. Magellan revealed that Venus lacks plate tectonics. The number and distribution of impact craters lead to the idea Venus resurfaced very rapidly, and inspired numerous models of lithospheric foundering and episodic plate tectonics. However we have no evidence that Venus ever experienced a plate tectonic regime. How is surface deformation affected if no volatiles are recycled into the interior? Although Venus is considered a ';stagnant' lid planet (lacking plate motion) today, we have evidence for recent volcanism. The VIRTIS instrument on Venus Express mapped the southern hemisphere at 1.02 microns, revealing areas likely to be unweathered, recent volcanic flows. Additionally, numerous studies have shown that the crater population is consistent with ongoing, regional resurfacing. How does deformation and volcanism occur in the absence of plates? At what rate is the planet resurfacing and thus outgassing? Does lithospheric recycling occur with plate tectonics? In the 25 years since Magellan, the design of Synthetic Aperture Radar has advanced tremendously, allowing order of magnitude improvements in altimetry and imaging. With these advanced tools, we can explore Venus' past and current tectonic states. Tesserae are highly deformed plateaus, thought to be possible remnants of Venus' earlier tectonic state. How did they form? Are they low in silica, like Earth's continents, indicating the presence of abundant water? Does the plains volcanism cover an earlier tectonic surface, or perhaps cover ancient impact basins? Was there an abrupt transition in tectonic style, perhaps due to degassing of the crust or a more gradual shift? What is the nature of Venus' modern tectonics? Is the lithosphere still deforming? Is there recent or active volcanism? Is volcanism confined to hotspots, areas above mantle plumes? Has plains volcanism ceased? What are the implications for volatile history? These questions can be addressed via a combination of high resolution altimetry, imaging, and surface emissivity mapping.

Wet Tectonics: A New Planetary Synthesis

NASA Astrophysics Data System (ADS)

Grimm, K. A.

2005-12-01

Most geoscientists (and geoscience textbooks) describe plate tectonics as a `solid-Earth' phenomenon, with fluids playing an important role in discrete geodynamic processes. As a community of diverse research specialists, the critical role of water is being widely elucidated, however these diverse studies do not address the fundamental origin and operation of the global plate tectonic phenomenon, and its expressions in planetary geodynamics and geomorphology. The Wet Tectonics hypothesis extends well beyond the plate tectonics paradigm, to constitute a new synthesis of diverse geoscience specializations and self-organizing complexity into a simple, internally consistent and explicitly testable model. The Wet Tectonics hypothesis asserts that Earth's plate tectonic system arose from and is the explicit and dynamic result of water interacting with the hot silicate mantle. The tectosphere is defined as an interactive functional (rather than structural, compositional or rheological) entity, a planetary-scale dynamic system of plate formation, plate motion, and rock/volatile recycling. Earth's tectosphere extends from the base of the asthenosphere to the top of the crust, arising and evolving as a dynamic pattern of organization that creates, orders and perpetuates itself. Earth's tectosphere is energetically-open, materially ajar (steady-state operation may not require sub-asthenospheric inputs; shifts between distinct tectonic modes may result from changes in coupling between the tectosphere and subasthenospheric reservoirs) and chemically-closed (i.e. the tectosphere recycles its own wastes). Water is a fundamental requirement in all of the constituent processes of Earth's tectosphere, including seafloor spreading, slab cooling/subsidence, plate motion, asthenosphere rheology, and subduction (where crustal and volatile recycling occur). As a working hypothesis, we suggest that the dynamic and persistent hydrosphere and tectosphere on planet Earth are fully interdependent and co-evolving phenomena. The concept of autocatalytic hypercycles has been adapted from molecular biology to resolve the apparent paradox of circular causality amongst the coupled phenomena of liquid water oceans and `plate tectonics'. This new planetary synthesis presents fundamental implications for geological, geophysical, Earth system and planetary sciences, as well as novel hypotheses concerning plate drive (gravity sliding ± slab pull), origin of plate tectonics (Hadean, >=4.4Ga), biogeochemical cycling (balanced global fluxes of water into and out of the tectosphere; is the asthenosphere continuously rehydrated via lateral advection) and planetary geomorphology (simple contrasts between Mars, Earth and Venus).

iPixel: a visual content-based and semantic search engine for retrieving digitized mammograms by using collective intelligence.

PubMed

Alor-Hernández, Giner; Pérez-Gallardo, Yuliana; Posada-Gómez, Rubén; Cortes-Robles, Guillermo; Rodríguez-González, Alejandro; Aguilar-Laserre, Alberto A

2012-09-01

Nowadays, traditional search engines such as Google, Yahoo and Bing facilitate the retrieval of information in the format of images, but the results are not always useful for the users. This is mainly due to two problems: (1) the semantic keywords are not taken into consideration and (2) it is not always possible to establish a query using the image features. This issue has been covered in different domains in order to develop content-based image retrieval (CBIR) systems. The expert community has focussed their attention on the healthcare domain, where a lot of visual information for medical analysis is available. This paper provides a solution called iPixel Visual Search Engine, which involves semantics and content issues in order to search for digitized mammograms. iPixel offers the possibility of retrieving mammogram features using collective intelligence and implementing a CBIR algorithm. Our proposal compares not only features with similar semantic meaning, but also visual features. In this sense, the comparisons are made in different ways: by the number of regions per image, by maximum and minimum size of regions per image and by average intensity level of each region. iPixel Visual Search Engine supports the medical community in differential diagnoses related to the diseases of the breast. The iPixel Visual Search Engine has been validated by experts in the healthcare domain, such as radiologists, in addition to experts in digital image analysis.

Hypsometry and relief analysis of the southern termination of the Calabrian arc, NE-Sicily (southern Italy)

NASA Astrophysics Data System (ADS)

Pavano, F.; Catalano, S.; Romagnoli, G.; Tortorici, G.

2018-03-01

Tectonic forcing causes the relief-building of mountain chains and enforces the surficial processes in a persistent dismantling of rock volumes, continuously modelling Earth's surface. Actually, we observe transient landscapes that have temporarily recorded tectonic forcing as a codified signal. The Late Quaternary tectonic evolution of northeastern Sicily, located along the Nubia-Eurasia plate boundary at the southern termination of the Calabrian arc, has been dominated by intense Plio-Pleistocene dynamics that severely modified the Late Miocene landscape. The present work aims to investigate geomorphically northeastern Sicily, essentially focusing on the hypsometric and relief analyses of the region in order to define how the topography responds to the post-Pliocene tectonic deformation. We apply different relief morphometric indices (Hypsometric Integral, Topographic Relief and Topographic Dissection) measured for each differently sized moving window, and we use different swath topographic profiles as well. Our analysis evidences differential morphological responses between distinct morphotectonic domains of the studied area, led by the combination of earlier morphological background and Late Quaternary tectonic deformation stages of the region. In addition, in the context of a constant and uniform tectonic uplift, the results define the general space- and time-relating pathways of the landscape geomorphic metrics. This enables us to bring out the controls of the vertical scale of landscape on hypsometry, exploring their mutual relationships. Finally, we reconstruct the Late Quaternary morphotectonic evolution of the region, defining the role played by the main tectonic alignments on the present geomorphic setting.

Geomorphic Response to Spatial and Temporal Tectonic uplift on the Kenya Rift of East African Rift System

NASA Astrophysics Data System (ADS)

Xue, L.; Abdelsalam, M. G.

2017-12-01

Tectonic uplifts of the shoulders of the East Africa Rift System (EARS) have significant impact on the geological record by reorganizing drainage systems, increasing sediment supply, and changing climate and biogeography. Recent studies in geochronology, geomorphology and geophysics have provided some understanding of the timing of tectonic uplift and its distribution pattern of the (EARS). We do not know how the vertical motion is localized along the rift axis and the relative roles of upwelling of magma and rift extensional processes play in tectonic uplift history. This work presents detailed morphometric study of the fluvial landscape response to the tectonic uplift and climate shifting of the Kenya Rift shoulders in order to reconstruct their incision history, with special attention to timing, location, and intensity of uplift episodes. This work compiles the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) and Sentinel-2A data, summarized previous 39Ar-40Ar and thermochronology data, and calculates long-term incision rate and geomorphic proxies (normalized steepness and chi-integral) along the Kenya Rift. It also models the age of tectonic/climatic events by using knickpoint celerity model and R/SR integrative approach. It found that the maximum long-term incision rates of 300 mm/kyr to be at the central Kenya Rift, possibly related to the mantle-driven process and rapid tectonic uplift. The geomorphic proxies indicate southward decreasing pattern of the short-term incision rate, possibly related to the migration of the mantle plume.

Structural and tectonic setting of the Charleston, South Carolina, region: Evidence from the Tertiary stratigraphic record

USGS Publications Warehouse

Weems, R.E.; Lewis, W.C.

2002-01-01

Eleven upper Eocene through Pliocene stratigraphic units occur in the subsurface of the region surrounding Charleston, South Carolina. These units contain a wealth of information concerning the long-term tectonic and structural setting of that area. These stratigraphic units have a mosaic pattern of distribution, rather than a simple layered pattern, because deposition, erosion, and tectonic warping have interacted in a complex manner through time. By generating separate structure-contour maps for the base of each stratigraphic unit, an estimate of the original basal surface of each unit can be reconstructed over wide areas. Changes in sea level over geologic time generate patterns of deposition and erosion that are geographically unique for the time of each transgression. Such patterns fail to persist when compared sequentially over time. In some areas, however, there has been persistent, repetitive net downward of upward movement over the past 34 m.y. These repetitive patterns of persistent motion are most readily attributable to tectonism. The spatial pattern of these high and low areas is complex, but it appears to correlate well with known tectonic features of the region. This correlation suggests that the tectonic setting of the Charleston region is controlled by scissors-like compression on a crustal block located between the north-trending Adams Run fault and the northwest-trending Charleston fault. Tectonism is localized in the Charleston region because it lies within a discrete hinge zone that accommodates structural movement between the Cape Fear arch and the Southeast Georgia embayment.

The revised tectonic history of Tharsis

NASA Astrophysics Data System (ADS)

Bouley, Sylvain; Baratoux, David; Paulien, Nicolas; Missenard, Yves; Saint-Bézar, Bertrand

2018-04-01

Constraining the timing of the emplacement of the volcano-tectonic province of Tharsis is critical to understanding the evolution of mantle, surface environment and climate of Mars. The growth of Tharsis had exerted stresses on the lithosphere, which were responsible for tectonic deformation, previously mapped as radial or concentric faults. Insights into the emplacement history of Tharsis may be gained from an analysis of the characteristics and ages of these tectonic features. The number, total length, linear density of extensional or compressional faults in the Tharsis region and deformation rates are reported for each of the following 6 stages: Early and Middle Noachian (stage 1); Late Noachian (stage 2); Early Hesperian (stage 3); Late Hesperian (stage 4), Early Amazonian (stage 5) and Middle Amazonian to Late Amazonian (stage 6). 8571 Tharsis-related tectonic features (radial or concentric to the center of Tharsis) were assigned to one of these periods of time based on their relationship with stratigraphic units defined in the most recent geological map. Intense faulting at Tempe Terra, Claritas and Coracis Fossae and Thaumasia Planum confirms that tectonic deformation started during the Noachian. However, we report a peak in both compressive and extensive rates of deformation during the Early Hesperian whereas the quantitative indicators for compressional and extensional tectonics vary within less than one order of magnitude from the Late Noachian to the Late Hesperian. These observations indicate a protracted growth of Tharsis during the first quarter of Mars evolution and declining from 3 Gyrs ago.

Induced earthquake magnitudes are as large as (statistically) expected

USGS Publications Warehouse

Van Der Elst, Nicholas; Page, Morgan T.; Weiser, Deborah A.; Goebel, Thomas; Hosseini, S. Mehran

2016-01-01

A major question for the hazard posed by injection-induced seismicity is how large induced earthquakes can be. Are their maximum magnitudes determined by injection parameters or by tectonics? Deterministic limits on induced earthquake magnitudes have been proposed based on the size of the reservoir or the volume of fluid injected. However, if induced earthquakes occur on tectonic faults oriented favorably with respect to the tectonic stress field, then they may be limited only by the regional tectonics and connectivity of the fault network. In this study, we show that the largest magnitudes observed at fluid injection sites are consistent with the sampling statistics of the Gutenberg-Richter distribution for tectonic earthquakes, assuming no upper magnitude bound. The data pass three specific tests: (1) the largest observed earthquake at each site scales with the log of the total number of induced earthquakes, (2) the order of occurrence of the largest event is random within the induced sequence, and (3) the injected volume controls the total number of earthquakes rather than the total seismic moment. All three tests point to an injection control on earthquake nucleation but a tectonic control on earthquake magnitude. Given that the largest observed earthquakes are exactly as large as expected from the sampling statistics, we should not conclude that these are the largest earthquakes possible. Instead, the results imply that induced earthquake magnitudes should be treated with the same maximum magnitude bound that is currently used to treat seismic hazard from tectonic earthquakes.

Providing Seismotectonic Information to the Public Through Continuously Updated National Earthquake Information Center Products

NASA Astrophysics Data System (ADS)

Bernardino, M. J.; Hayes, G. P.; Dannemann, F.; Benz, H.

2012-12-01

One of the main missions of the United States Geological Survey (USGS) National Earthquake Information Center (NEIC) is the dissemination of information to national and international agencies, scientists, and the general public through various products such as ShakeMap and earthquake summary posters. During the summer of 2012, undergraduate and graduate student interns helped to update and improve our series of regional seismicity posters and regional tectonic summaries. The "Seismicity of the Earth (1900-2007)" poster placed over a century's worth of global seismicity data in the context of plate tectonics, highlighting regions that have experienced great (M+8.0) earthquakes, and the tectonic settings of those events. This endeavor became the basis for a series of more regionalized seismotectonic posters that focus on major subduction zones and their associated seismicity, including the Aleutian and Caribbean arcs. The first round of these posters were inclusive of events through 2007, and were made with the intent of being continually updated. Each poster includes a regional tectonic summary, a seismic hazard map, focal depth cross-sections, and a main map that illustrates the following: the main subduction zone and other physiographic features, seismicity, and rupture zones of historic great earthquakes. Many of the existing regional seismotectonic posters have been updated and new posters highlighting regions of current seismological interest have been created, including the Sumatra and Java arcs, the Middle East region and the Himalayas (all of which are currently in review). These new editions include updated lists of earthquakes, expanded tectonic summaries, updated relative plate motion vectors, and major crustal faults. These posters thus improve upon previous editions that included only brief tectonic discussions of the most prominent features and historic earthquakes, and which did not systematically represent non-plate boundary faults. Regional tectonic summaries provide the public with immediate background information useful for teaching and media related purposes and are an essential component to many NEIC products. As part of the NEIC's earthquake response, rapid earthquake summary posters are created in the hours following a significant global earthquake. These regional tectonic summaries are included in each earthquake summary poster along with a discussion of the event, written by research scientists at the NEIC, often with help from regional experts. Now, through the efforts of this and related studies, event webpages will automatically contain a regional tectonic summary immediately after an event has been posted. These new summaries include information about plate boundary interactions and other associated tectonic elements, trends in seismicity and brief descriptions of significant earthquakes that have occurred in a region. The tectonic summaries for the following regions have been updated as part of this work: South America, the Caribbean, Alaska and the Aleutians, Kuril-Kamchatka, Japan and vicinity, and Central America, with newly created summaries for Sumatra and Java, the Mediterranean, Middle East, and the Himalayas. The NEIC is currently planning to integrate concise stylized maps with each tectonic summary for display on the USGS website.

Textpresso: An Ontology-Based Information Retrieval and Extraction System for Biological Literature

PubMed Central

Müller, Hans-Michael; Kenny, Eimear E

2004-01-01

We have developed Textpresso, a new text-mining system for scientific literature whose capabilities go far beyond those of a simple keyword search engine. Textpresso's two major elements are a collection of the full text of scientific articles split into individual sentences, and the implementation of categories of terms for which a database of articles and individual sentences can be searched. The categories are classes of biological concepts (e.g., gene, allele, cell or cell group, phenotype, etc.) and classes that relate two objects (e.g., association, regulation, etc.) or describe one (e.g., biological process, etc.). Together they form a catalog of types of objects and concepts called an ontology. After this ontology is populated with terms, the whole corpus of articles and abstracts is marked up to identify terms of these categories. The current ontology comprises 33 categories of terms. A search engine enables the user to search for one or a combination of these tags and/or keywords within a sentence or document, and as the ontology allows word meaning to be queried, it is possible to formulate semantic queries. Full text access increases recall of biological data types from 45% to 95%. Extraction of particular biological facts, such as gene-gene interactions, can be accelerated significantly by ontologies, with Textpresso automatically performing nearly as well as expert curators to identify sentences; in searches for two uniquely named genes and an interaction term, the ontology confers a 3-fold increase of search efficiency. Textpresso currently focuses on Caenorhabditis elegans literature, with 3,800 full text articles and 16,000 abstracts. The lexicon of the ontology contains 14,500 entries, each of which includes all versions of a specific word or phrase, and it includes all categories of the Gene Ontology database. Textpresso is a useful curation tool, as well as search engine for researchers, and can readily be extended to other organism-specific corpora of text. Textpresso can be accessed at http://www.textpresso.org or via WormBase at http://www.wormbase.org. PMID:15383839

The tectonic evolution of the Madrean Archipelago and its impact on the geoecology of the Sky Islands

Treesearch

David Coblentz

2005-01-01

While the unique geographic location of the Sky Islands is well recognized as a primary factor for the elevated biodiversity of the region, its unique tectonic history is often overlooked. The mixing of tectonic environments is an important supplement to the mixing of flora and faunal regimes in contributing to the biodiversity of the Madrean Archipelago. The Sky...

78 FR 48421 - Publication of North American Datum of 1983 (2011) Epoch 2010.00, North American Datum of 1983...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-08

... of 1983'' (or ``NAD 83''). The new realizations are NAD 83 (2011) epoch 2010.00 [for the North America and Caribbean tectonic plates], NAD 83 (MA11) epoch 2010.00 [for the Mariana tectonic plate] and NAD 83 (PA11) epoch 2010.00 [for the Pacific tectonic plate]. These three realizations supersede all...

Plate tectonics on Venus

NASA Technical Reports Server (NTRS)

Anderson, D. L.

1981-01-01

The high surface temperature of Venus implies a permanently buoyant lithosphere and a thick basaltic crust. Terrestrial-style tectonics with deep subduction and crustal recycling is not possible. Overthickened basaltic crust partially melts instead of converting to eclogite. Because mantle magmas do not have convenient access to the surface the Ar-40 abundance in the atmosphere should be low. Venus may provide an analog to Archean tectonics on the earth.

Tectonics of the central Andes

NASA Technical Reports Server (NTRS)

Bloom, Arthur L.; Isacks, Bryan L.; Fielding, Eric J.; Fox, Andrew N.; Gubbels, Timothy L.

1989-01-01

Acquisition of nearly complete coverage of Thematic Mapper data for the central Andes between about 15 to 34 degrees S has stimulated a comprehensive and unprecedented study of the interaction of tectonics and climate in a young and actively developing major continental mountain belt. The current state of the synoptic mapping of key physiographic, tectonic, and climatic indicators of the dynamics of the mountain/climate system are briefly reviewed.

Tectonic control of complex slope failures in the Ameka River Valley (Lower Gibe Area, central Ethiopia): Implications for landslide formation

NASA Astrophysics Data System (ADS)

Kycl, Petr; Rapprich, Vladislav; Verner, Kryštof; Novotný, Jan; Hroch, Tomáš; Mišurec, Jan; Eshetu, Habtamu; Tadesse Haile, Ezra; Alemayehu, Leta; Goslar, Tomasz

2017-07-01

Even though major faults represent important landslide controlling factors, the role the tectonic setting in actively spreading rifts plays in the development of large complex landslides is seldom discussed. The Ameka complex landslide area is located on the eastern scarp of the Gibe Gorge, approximately 45 km to the west of the Main Ethiopian Rift and 175 km to the southwest of Addis Ababa. Investigation of the complex landslide failures required a combination of satellite and airborne data-based geomorphology, geological field survey complemented with structural analysis, radiocarbon geochronology and vertical electric sounding. The obtained observations confirmed the multiphase evolution of the landslide area. We have documented that, apart from climatic and lithological conditions, the main triggering factor of the Ameka complex landslide is the tectonic development of this area. The E-W extension along the NNE-SSW trending Main Ethiopian Rift is associated with the formation of numerous parallel normal faults, such as the Gibe Gorge fault and the almost perpendicular scissor faults. The geometry of the slid blocks of coherent lithology have inherited the original tectonic framework, which suggests the crucial role tectonics play in the fragmentation of the compact rock-masses, and the origin and development of the Ameka complex landslide area. Similarly, the main scarps were also parallel to the principal tectonic features. The local tectonic framework is dominated by faults of the same orientation as the regional structures of the Main Ethiopian Rift. Such parallel tectonic frameworks display clear links between the extension of the Main Ethiopian Rift and the tectonic development of the landslide area. The Ameka complex landslide developed in several episodes over thousands of years. According to the radiocarbon data, the last of the larger displaced blocks (representing only 2% of the total area) most likely slid down in the seventh century AD. The main scarps, namely the high scarps in the western part, are unstable over the long term and toppling and falling-type slope movements can be expected here in the future.

Research on Distribution Characteristics of Lunar Faults

NASA Astrophysics Data System (ADS)

Lu, T.; Chen, S.; Lu, P.

2017-12-01

Circular and linear tectonics are two major types of tectonics on lunar surface. Tectonic characteristics are of significance for researching about lunar geological evolution. Linear tectonics refers to those structures extending linearly on a lunar surface. Their distribution are closely related to the internal geological actions of the moon. Linear tectonics can integrally or locally express the structural feature and the stress status as well as showing the geological information of the interior of the moon. Faults are of the largest number and are of a certain distribution regularity among the linear tectonics, and are always the focus of domestic and overseas lunar tectonic research. Based on remote sensing geology and theory of traditional tectonic geology, We use a variety of remote sensing data processing to establish lunar linear tectonic interpretation keys with lunar spectral, terrain and gravity data. On this basis, interpretation of faults of the whole moon was primarily conducted from Chang'e-2 CCD image data and reference to wide-angle camera data of LROC, laser altimeter data of LOLA and gravity data of GRAIL. Statistical analysis of the number and distribution characteristics of whole lunar faults are counted from three latitude ranges of low, middle and high latitudes, then analyze the azimuth characteristics of the faults at different latitudes. We concluded that S-N direction is a relatively developed orientation at low latitudes. Middle latitudes reveal six preferred orientations of N-E, N-W, NN-E, NN-W, N-EE and N-WW directions. There are sparse faults of E-W direction distribution at low and middle latitudes. Meanwhile, the largest number of faults of E-W direction on lunar surface are mainly distributed along high latitudes with continuity and regularity. Analyzing faults of Mare Imbrium by the method of Euler deconvolution. The result show that there are two different properties of faults in Mare Imbrium. In conclusion, we suggest that the dynamics mechanism of the formation of the lunar faults is mainly affected by despinning, followed by tidal force and global contraction.

Whole Planet Coupling from Climate to Core: Implications for the Evolution of Rocky Planets and their Prospects for Habitability

NASA Astrophysics Data System (ADS)

Foley, B. J.; Driscoll, P. E.

2015-12-01

Many factors have conspired to make Earth a home to complex life. Earth has abundant water due to a combination of factors, including orbital distance and the climate regulating feedbacks of the long-term carbon cycle. Earth has plate tectonics, which is crucial for maintaining long-term carbon cycling and may have been an important energy source for the origin of life in seafloor hydrothermal systems. Earth also has a strong magnetic field that shields the atmosphere from the solar wind and the surface from high-energy particles. Synthesizing recent work on these topics shows that water, a temperate climate, plate tectonics, and a strong magnetic field are linked together through a series of negative feedbacks that stabilize the system over geologic timescales. Although the physical mechanism behind plate tectonics on Earth is still poorly understood, climate is thought to be important. In particular, temperate surface temperatures are likely necessary for plate tectonics because they allow for liquid water that may be capable of significantly lowering lithospheric strength, increase convective stresses in the lithosphere, and enhance the effectiveness of "damage" processes such as grainsize reduction. Likewise, plate tectonics is probably crucial for maintaining a temperate climate on Earth through its role in facilitating the long-term carbon cycle, which regulates atmospheric CO2 levels. Therefore, the coupling between plate tectonics and climate is a feedback that is likely of first order importance for the evolution of rocky planets. Finally, plate tectonics is thought to be important for driving the geodynamo. Plate tectonics efficiently cools the mantle, leading to vigorous thermo-chemical convection in the outer core and dynamo action; without plate tectonics inefficient mantle cooling beneath a stagnant lid may prevent a long-lived magnetic field. As the magnetic field shields a planet's atmosphere from the solar wind, the magnetic field may be important for preserving hydrogen, and therefore water, on the surface. Thus whole planet coupling between the magnetic field, atmosphere, mantle, and core is possible. We lay out the basic physics governing whole planet coupling, and discuss the implications this coupling has for the evolution of rocky planets and their prospects for hosting life.

Holocene vertical tectonic movements of the Taipei Basin, northern Taiwan and its implications

NASA Astrophysics Data System (ADS)

Chen, B.; Hsieh, M.; Lai, T.; Liew, P.

2007-12-01

Many geological data of the Taipei Basin, although, have been published by various studies in past decades, however, vertical tectonic movement rate of the Basin was not well understood so far. This study, therefore, used radiocarbon dates, obtained from fifteen boreholes in the Basin, to calculate the Holocene vertical tectonic movement rate. In addition to the derived tectonic movement rate, this study also discussed the causes of the tectonic patterns of the Taipei Basin. The Taipei Basin, located in the northern Taiwan, was a half graben subsided and extended along the western boundary, the Shangiao Normal Fault, of the Basin. The Holocene vertical tectonic movement rate of the Basin were calculated based on 94 radiocarbon dates in fifteen boreholes, the elevations of the radiocarbon dating samples, and the eustatic sea-level curve of the past 15 ka. The results showed the rate in the western part of the Basin, was -2.2 -- -0.9 mm/yr (negative value indicates subsiding, and positive value indicates uplifting). In the central part of the Basin, the rate was ca. -1 -- 1 mm/yr while in the eastern part of the Basin, the rate was 0.1 -- 1.6 mm/yr. Along the Shiangiao Fault, the rate of the hanging-wall was ca. -1.6 -- -0.4 mm/yr and the rate of the footwall was ca. 0 mm/yr. According to the results of this study, the present territory of the Taipei Basin was not actually consistent with the tectonic subsiding region. The vertical tectonic movement pattern demonstrated subsidence in the western part and uplift in the eastern part of the Taipei Basin. The subsidence of the western part was controlled by the extension of the Shangiao Faul. The uplift of the eastern part might be ascribed to the roll-over of the Fault. Another possibility is that the uplift of the east was controlled by the same behavior as the Western Foothills.Consequently, the deposition of the eastern part of the Basin, wass mainly related to the accommodations due to sea-level rise but not tectonic subsidence.

Estimating Stresses, Fault Friction and Fluid Pressure from Topography and Coseismic Slip Models

NASA Astrophysics Data System (ADS)

Styron, R. H.; Hetland, E. A.

2014-12-01

Stress is a first-order control on the deformation state of the earth. However, stress is notoriously hard to measure, and researchers typically only estimate the directions and relative magnitudes of principal stresses, with little quantification of the uncertainties or absolute magnitude. To improve upon this, we have developed methods to constrain the full stress tensor field in a region surrounding a fault, including tectonic, topographic, and lithostatic components, as well as static friction and pore fluid pressure on the fault. Our methods are based on elastic halfspace techniques for estimating topographic stresses from a DEM, and we use a Bayesian approach to estimate accumulated tectonic stress, fluid pressure, and friction from fault geometry and slip rake, assuming Mohr-Coulomb fault mechanics. The nature of the tectonic stress inversion is such that either the stress maximum or minimum is better constrained, depending on the topography and fault deformation style. Our results from the 2008 Wenchuan event yield shear stresses from topography up to 20 MPa (normal-sinistral shear sense) and topographic normal stresses up to 80 MPa on the faults; tectonic stress had to be large enough to overcome topography to produce the observed reverse-dextral slip. Maximum tectonic stress is constrained to be >0.3 * lithostatic stress (depth-increasing), with a most likely value around 0.8, trending 90-110°E. Minimum tectonic stress is about half of maximum. Static fault friction is constrained at 0.1-0.4, and fluid pressure at 0-0.6 * total pressure on the fault. Additionally, the patterns of topographic stress and slip suggest that topographic normal stress may limit fault slip once failure has occurred. Preliminary results from the 2013 Balochistan earthquake are similar, but yield stronger constraints on the upper limits of maximum tectonic stress, as well as tight constraints on the magnitude of minimum tectonic stress and stress orientation. Work in progress on the Wasatch fault suggests that maximum tectonic stress may also be able to be constrained, and that some of the shallow rupture segmentation may be due in part to localized topographic loading. Future directions of this work include regions where high relief influences fault kinematics (such as Tibet).

Formalizing An Approach to Curate the Global Change Master Directory (GCMD)'s Controlled Vocabularies (Keywords) Through a Keyword Governance Process and Community Involvement

NASA Astrophysics Data System (ADS)

Stevens, T.

2016-12-01

NASA's Global Change Master Directory (GCMD) curates a hierarchical set of controlled vocabularies (keywords) covering Earth sciences and associated information (data centers, projects, platforms, and instruments). The purpose of the keywords is to describe Earth science data and services in a consistent and comprehensive manner, allowing for precise metadata search and subsequent retrieval of data and services. The keywords are accessible in a standardized SKOS/RDF/OWL representation and are used as an authoritative taxonomy, as a source for developing ontologies, and to search and access Earth Science data within online metadata catalogs. The keyword curation approach involves: (1) receiving community suggestions; (2) triaging community suggestions; (3) evaluating keywords against a set of criteria coordinated by the NASA Earth Science Data and Information System (ESDIS) Standards Office; (4) implementing the keywords; and (5) publication/notification of keyword changes. This approach emphasizes community input, which helps ensure a high quality, normalized, and relevant keyword structure that will evolve with users' changing needs. The Keyword Community Forum, which promotes a responsive, open, and transparent process, is an area where users can discuss keyword topics and make suggestions for new keywords. Others could potentially use this formalized approach as a model for keyword curation.

Keywords to Recruit Spanish- and English-Speaking Participants: Evidence From an Online Postpartum Depression Randomized Controlled Trial

PubMed Central

Kelman, Alex R; Muñoz, Ricardo F

2014-01-01

Background One of the advantages of Internet-based research is the ability to efficiently recruit large, diverse samples of international participants. Currently, there is a dearth of information on the behind-the-scenes process to setting up successful online recruitment tools. Objective The objective of the study was to examine the comparative impact of Spanish- and English-language keywords for a Google AdWords campaign to recruit pregnant women to an Internet intervention and to describe the characteristics of those who enrolled in the trial. Methods Spanish- and English-language Google AdWords campaigns were created to advertise and recruit pregnant women to a Web-based randomized controlled trial for the prevention of postpartum depression, the Mothers and Babies/Mamás y Bebés Internet Project. Search engine users who clicked on the ads in response to keyword queries (eg, pregnancy, depression and pregnancy) were directed to the fully automated study website. Data on the performance of keywords associated with each Google ad reflect Web user queries from February 2009 to June 2012. Demographic information, self-reported depression symptom scores, major depressive episode status, and Internet use data were collected from enrolled participants before randomization in the intervention study. Results The Google ads received high exposure (12,983,196 impressions) and interest (176,295 clicks) from a global sample of Web users; 6745 pregnant women consented to participate and 2575 completed enrollment in the intervention study. Keywords that were descriptive of pregnancy and distress or pregnancy and health resulted in higher consent and enrollment rates (ie, high-performing ads). In both languages, broad keywords (eg, pregnancy) had the highest exposure, more consented participants, and greatest cost per consent (up to US $25.77 per consent). The online ads recruited a predominantly Spanish-speaking sample from Latin America of Mestizo racial identity. The English-speaking sample was also diverse with most participants residing in regions of Asia and Africa. Spanish-speaking participants were significantly more likely to be of Latino ethnic background, not married, completed fewer years of formal education, and were more likely to have accessed the Internet for depression information (P<.001). Conclusions The Internet is an effective method for reaching an international sample of pregnant women interested in online interventions to manage changes in their mood during the perinatal period. To increase efficiency, Internet advertisements need to be monitored and tailored to reflect the target population’s conceptualization of health issues being studied. Trial Registration ClinicalTrials.gov NCT00816725; http://clinicaltrials.gov/show/NCT00816725 (Archived by WebCite at http://www.webcitation.org/6LumonjZP). PMID:24407163

Difference in rockburst hazard in ore and coal mines

NASA Astrophysics Data System (ADS)

Lovchikov, AV

2018-03-01

In the Russian mining and engineering literature, in most cases, there is no difference in the assessment of the rockburst hazards in metal and coal mines. Nevertheless, it exists, in view of the difference in geological and geotechnical conditions of coal and ore deposits. Since ore deposits occur in the solid magmatic or metamorphic rock masses, the strongest induced earthquakes are much more powerful in ore mines than in coal mines. The main difference of rockbursting lies in the difference of natural stress state: gravity stress state in the coal fields and gravity-and-tectonic stress state in ore mines. The actual stresses are mostly vertical in the first case and horizontal in the second case, which conditions the difference in rockburst hazard in coal and ore mines.

Generation and Initiation of Plate Tectonics on Terrestrail Planets

NASA Astrophysics Data System (ADS)

Foley, Bradford J.

The question of why plate tectonics occurs on Earth, but not on the other planets of our solar system, is one of the most fundamental issues in geophysics and planetary science. I study this problem using numerical simulations of mantle convection with a damage-grainsize feedback (grain-damage) to constrain the conditions necessary for plate tectonics to occur on a terrestrial planet, and how plate tectonics initiates. In Chapter 2, I use numerical simulations to determine how large a viscosity ratio, between pristine lithosphere and mantle, damage can offset to allow mobile (plate-like) convection. I then use the numerical results to formulate a new scaling law to describe the boundary between stagnant lid and plate-like regimes of mantle convection. I hypothesize that damage must reduce the viscosity of shear zones in the lithosphere to a critical value, equivalent to the underlying mantle viscosity, in order for plate tectonics to occur, and demonstrate that a scaling law based on this hypothesis reproduces the numerical results. For the Earth, damage is efficient in the lithosphere and provides a viable mechanism for the operation of plate tectonics. I apply my theory to super-Earths and map out the transition between plate-like and stagnant lid convection with a "planetary plate-tectonic phase" diagram in planet size-surface temperature space. Both size and surface temperature are important, with plate tectonics being favored for larger, cooler planets. This gives a natural explanation for Earth, Venus, and Mars, and implies that plate tectonics on exoplanets should correlate with size, incident solar radiation, and atmospheric composition. In Chapters 3 and 4 I focus on the initiation of plate tectonics. In Chapter 3, I develop detailed scaling laws describing plate speed and heat flow for mantle convection with grain-damage across a wide parameter range, with the intention of applying these scaling laws to the early Earth in Chapter 4. Convection with grain-damage scales differently than Newtonian convection; whereas the Nusselt number, Nu, typically scales with the Rayleigh number, Ra, to the 1/3 power, for grain-damage this exponent is larger because increasing Ra also enhances damage. In addition, Nu and plate velocity are also functions of the damage to healing ratio, (D/H); increasing D/H increases Nu (or plate speed) because more damage leads to more vigorous convection. In Chapter 4, I demonstrate that subduction can be sustained on the early Earth, that the style of subduction at this time was different than modern day plate tectonics, and that such subduction (or proto-subduction) can initiate rapidly after magma ocean solidification. The scaling laws from Chapter 3 show that, though either higher interior mantle temperatures or higher surface temperatures lead to slower plates, proto-subduction, with plate speeds of at least 1.5 cm/yr, can still be maintained in the Hadean, even if the primordial atmosphere was CO2 rich. Furthermore, when the interior mantle temperature is high (e.g. above ≈ 2000 K), the mode of subduction switches to a "sluggish subduction" style, where downwellings are more drip-like than slab-like and plate boundaries are more diffuse. Numerical models of post-magma ocean mantle convection, and a scaling analysis based on the results of these models, demonstrate that proto-plate tectonics likely initiates within ˜100 Myrs of magma ocean solidification. Combined with the conclusion that proto-subduction could be maintained on the early Earth, my results are consistent with evidence for Hadean subduction from zircon data, and indicate that the subduction inferred from zircons may have been distinct from modern day plate tectonics. After the initiation of proto-subduction, which occurs as a rapid overturn of the whole lithosphere, mobile lid convection takes place as non-plate tectonic "sluggish subduction" As both the mantle interior and climate cool, modern style plate tectonics develops. The rapid, initial subduction event may help hasten the onset of modern style plate tectonics by drawing excess CO 2 out of the atmosphere and cooling the climate.

Tracking the emergence of synthetic biology.

PubMed

Shapira, Philip; Kwon, Seokbeom; Youtie, Jan

2017-01-01

Synthetic biology is an emerging domain that combines biological and engineering concepts and which has seen rapid growth in research, innovation, and policy interest in recent years. This paper contributes to efforts to delineate this emerging domain by presenting a newly constructed bibliometric definition of synthetic biology. Our approach is dimensioned from a core set of papers in synthetic biology, using procedures to obtain benchmark synthetic biology publication records, extract keywords from these benchmark records, and refine the keywords, supplemented with articles published in dedicated synthetic biology journals. We compare our search strategy with other recent bibliometric approaches to define synthetic biology, using a common source of publication data for the period from 2000 to 2015. The paper details the rapid growth and international spread of research in synthetic biology in recent years, demonstrates that diverse research disciplines are contributing to the multidisciplinary development of synthetic biology research, and visualizes this by profiling synthetic biology research on the map of science. We further show the roles of a relatively concentrated set of research sponsors in funding the growth and trajectories of synthetic biology. In addition to discussing these analyses, the paper notes limitations and suggests lines for further work.

Assessing public health job portals over the internet.

PubMed

Joshi, Ashish; Mirza, Attiqa; McFarlane, Kim; Amadi, Chioma

2016-09-01

The objective of our study was to search existing public health job websites over the internet and describe the challenges related to finding these job websites. An internet search was conducted using different search engines, including Google, Yahoo and Bing, with several keywords including: Public Health Jobs, Epidemiology Jobs, Biostatistics Jobs, Health Policy and Management Jobs, Community Health Jobs, Health Administration Jobs, Nutrition Jobs, Environmental and Occupational Health Science Jobs, GIS Jobs, and Public Health Informatics Jobs. We recorded the first 20 websites that appeared in the results of each keyword search, thus generating 600 URLs. Duplicate sites and non-functional sites were excluded from this search, allowing analysis of unique sites only. The initial search resulted in 600 websites of which there were 470 duplicates. More than half of the website categories were ".com" (54%; n = 323) followed by ".gov" (19%; n = 111) and ".edu" 15% (n = 90). Results of our findings showed 194 unique websites resulting from a search of 600 website links. More than half of them had actual public health or its related jobs (56%; n = 108). There is a need to establish standard occupational classification categories for the public health workforce. © Royal Society for Public Health 2016.

Query-Biased Preview over Outsourced and Encrypted Data

PubMed Central

Luo, Guangchun; Qin, Ke; Chen, Aiguo

2013-01-01

For both convenience and security, more and more users encrypt their sensitive data before outsourcing it to a third party such as cloud storage service. However, searching for the desired documents becomes problematic since it is costly to download and decrypt each possibly needed document to check if it contains the desired content. An informative query-biased preview feature, as applied in modern search engine, could help the users to learn about the content without downloading the entire document. However, when the data are encrypted, securely extracting a keyword-in-context snippet from the data as a preview becomes a challenge. Based on private information retrieval protocol and the core concept of searchable encryption, we propose a single-server and two-round solution to securely obtain a query-biased snippet over the encrypted data from the server. We achieve this novel result by making a document (plaintext) previewable under any cryptosystem and constructing a secure index to support dynamic computation for a best matched snippet when queried by some keywords. For each document, the scheme has O(d) storage complexity and O(log(d/s) + s + d/s) communication complexity, where d is the document size and s is the snippet length. PMID:24078798

SNOMED CT module-driven clinical archetype management.

PubMed

Allones, J L; Taboada, M; Martinez, D; Lozano, R; Sobrido, M J

2013-06-01

To explore semantic search to improve management and user navigation in clinical archetype repositories. In order to support semantic searches across archetypes, an automated method based on SNOMED CT modularization is implemented to transform clinical archetypes into SNOMED CT extracts. Concurrently, query terms are converted into SNOMED CT concepts using the search engine Lucene. Retrieval is then carried out by matching query concepts with the corresponding SNOMED CT segments. A test collection of the 16 clinical archetypes, including over 250 terms, and a subset of 55 clinical terms from two medical dictionaries, MediLexicon and MedlinePlus, were used to test our method. The keyword-based service supported by the OpenEHR repository offered us a benchmark to evaluate the enhancement of performance. In total, our approach reached 97.4% precision and 69.1% recall, providing a substantial improvement of recall (more than 70%) compared to the benchmark. Exploiting medical domain knowledge from ontologies such as SNOMED CT may overcome some limitations of the keyword-based systems and thus improve the search experience of repository users. An automated approach based on ontology segmentation is an efficient and feasible way for supporting modeling, management and user navigation in clinical archetype repositories. Copyright © 2013 Elsevier Inc. All rights reserved.

Query-biased preview over outsourced and encrypted data.

PubMed

Peng, Ningduo; Luo, Guangchun; Qin, Ke; Chen, Aiguo

2013-01-01

For both convenience and security, more and more users encrypt their sensitive data before outsourcing it to a third party such as cloud storage service. However, searching for the desired documents becomes problematic since it is costly to download and decrypt each possibly needed document to check if it contains the desired content. An informative query-biased preview feature, as applied in modern search engine, could help the users to learn about the content without downloading the entire document. However, when the data are encrypted, securely extracting a keyword-in-context snippet from the data as a preview becomes a challenge. Based on private information retrieval protocol and the core concept of searchable encryption, we propose a single-server and two-round solution to securely obtain a query-biased snippet over the encrypted data from the server. We achieve this novel result by making a document (plaintext) previewable under any cryptosystem and constructing a secure index to support dynamic computation for a best matched snippet when queried by some keywords. For each document, the scheme has O(d) storage complexity and O(log(d/s) + s + d/s) communication complexity, where d is the document size and s is the snippet length.

Emollient treatment of atopic dermatitis: latest evidence and clinical considerations

PubMed Central

Kung, Jeng Sum Charmaine; Ng, Wing Gi Gigi; Leung, Ting Fan

2018-01-01

Aim To review current classes of emollients in the market, their clinical efficacy in atopic dermatitis (AD) and considerations for choice of an emollient. Methods PubMed Clinical Queries under Clinical Study Categories (with Category limited to Therapy and Scope limited to Narrow) and Systematic Reviews were used as the search engine. Keywords of ‘emollient or moisturizer’ and ‘atopic dermatitis’ were used. Overview of findings Using the keywords of ‘emollient’ and ‘atopic dermatitis’, there were 105 and 36 hits under Clinical Study Categories (with Category limited to Therapy and Scope limited to Narrow) and Systematic Reviews, respectively. Plant-derived products, animal products and special ingredients were discussed. Selected proprietary products were tabulated. Conclusions A number of proprietary emollients have undergone trials with clinical data available on PubMed-indexed journals. Most moisturizers showed some beneficial effects, but there was generally no evidence that one moisturizer is superior to another. Choosing an appropriate emollient for AD patients would improve acceptability and adherence for emollient treatment. Physician’s recommendation is the primary consideration for patients when selecting a moisturizer/emollient; therefore, doctors should provide evidence-based information about these emollients. PMID:29692852

The Surface of Venus

NASA Astrophysics Data System (ADS)

Ivanov, M. A.; Head, J. W.

2018-03-01

This chapter reviews the conditions under which the basic landforms of Venus formed, interprets their nature, and analyzes their local, regional, and global age relationships. The strong greenhouse effect on Venus causes hyper-dry, almost stagnant near-surface environments. These conditions preclude water-driven, and suppress wind-related, geological processes; thus, the common Earth-like water-generated geological record of sedimentary materials does not currently form on Venus. Three geological processes are important on the planet: volcanism, tectonics, and impact cratering. The small number of impact craters on Venus ( 1,000) indicates that their contribution to resurfacing is minor. Volcanism and tectonics are the principal geological processes operating on Venus during its observable geologic history. Landforms of the volcanic and tectonic nature have specific morphologies, which indicate different modes of formation, and their relationships permit one to establish their relative ages. Analysis of these relationships at the global scale reveals that three distinct regimes of resurfacing comprise the observable geologic history of Venus: (1) the global tectonic regime, (2) the global volcanic regime, and (3) the network rifting-volcanism regime. During the earlier global tectonic regime, tectonic resurfacing dominated. Tectonic deformation at this time caused formation of strongly tectonized terrains such as tessera, and deformational belts. Exposures of these units comprise 20% of the surface of Venus. The apparent beginning of the global tectonic regime is related to the formation of tessera, which is among the oldest units on Venus. The age relationships among the tessera structures indicate that this terrain is the result of crustal shortening. During the global volcanic regime, volcanism overwhelmed tectonic activity and caused formation of vast volcanic plains that compose 60% of the surface of Venus. The plains show a clear stratigraphic sequence from older shield plains to younger regional plains. The distinctly different morphologies of the plains indicate different volcanic formation styles ranging from eruption through broadly distributed local sources of shield plains to the volcanic flooding of regional plains. The density of impact craters on units of the tectonic and volcanic regimes suggests that these regimes characterized about the first one-third of the visible geologic history of Venus. During this time, 80%–85% of the surface of the planet was renovated. The network rifting-volcanism regime characterized the last two-thirds of the visible geologic history of Venus. The major components of the regime include broadly synchronous lobate plains and rift zones. Although the network rifting-volcanism regime characterized 2/3 of the visible geologic history of Venus, only 15%–20% of the surface was resurfaced during this time. This means that the level of endogenous activity during this time has dropped by about an order of magnitude compared with the earlier regimes.

Extensional tectonics on continents and the transport of heat and matter

NASA Technical Reports Server (NTRS)

Neugebauer, H. J.

1985-01-01

Intracontinental zones of extensional tectonic style are commonly of finite width and length. Associated sedimentary troughs are fault-controlled. The evolution of those structures is accompanied by volcanic activity of variable intensity. The characteristic surface structures are usually underlaid by a lower crust of the transitional type while deeper subcustal areas show delayed travel times of seismic waves especially at young tectonic provinces. A correspondence between deep-seated processes and zones of continental extension appears obvious. A sequential order of mechanisms and their importance are discussed in the light of modern data compilations and quantitative kinematic and dynamic approaches. The Cenozoic exensional tectonics related with the Rhine River are discussed.

On the breakup of tectonic plates by polar wandering

NASA Technical Reports Server (NTRS)

Liu, H.-S.

1974-01-01

The equations for the stresses in a homogeneous shell of uniform thickness caused by a shift of the axis of rotation are derived. The magnitude of these stresses reaches a maximum value of the order of 10 to the 9th power dyn/sq cm, which is sufficient for explaining a tectonic breakup. In order to deduce the fracture pattern according to which the breakup of tectonic plates can be expected the theory of plastic deformation of shells is applied. The analysis of this pattern gives an explanation of the existing boundary systems of the major tectonic plates as described by Morgan (1968), LePichon (1968) and Isacks et al. (1968).

Geodetic, Geologic and Seismic Interdisciplinary Research of Tectonically Caused Movements in the Wider Area of the City of Zagreb

NASA Astrophysics Data System (ADS)

Dapo, A.; Pribicevic, B.; Herak, M.; Prelogovic, E.

2012-04-01

Since the last great earthquake in 1880 which shook the Zagreb area with IX° MCS, tectonic movements and models of numerous Zagreb faults have been the focal point of Croatian geologists, seismologists and in the last 15 years also geodetic scientists, who all have been working in the scope of their scientific branches on bringing the light to the tectonic mechanisms in the wider Zagreb area. Since it is tectonically very active area and being the Capitol city of the Croatia with very high population density it is of utmost importance to understand those mechanisms and to according to them find the best possible measures for protecting people and valuables. Best results are certainly going to be achieved through the interdisciplinary approach. That is why this paper presents first interdisciplinary results from geodetic, geologic and seismic researches and their contribution to the collective knowledge about tectonic movements in the wider area of the City of Zagreb.

Some methodological aspects of tectonic stress reconstruction based on geological indicators

NASA Astrophysics Data System (ADS)

Sim, Lidiya A.

2012-03-01

The impact of the initial heterogeneity in rocks on the distribution of slickensides (slip planes), which are used to reconstruct local stress-state, is discussed. The stress-state was reconstructed by a graphic variant of the cinematic method. A new type of stress-state - Variation of Stress-State Type (VSST) - is introduced. The VSST is characterized by dislocation vectors originated both by uniaxial compression and uniaxial tension in the same rock volume, i.e. coefficient μσ = 1-2R varies from +1 to -1. The reasons for differences between slip planes from those predicted by the model are discussed. The distribution of slip planes depends on the stress-state type (μσ coefficient) and on the initial heterogeneity of the rocks. A criterion for the identification of tectonic stress rank is suggested. It is based on the models of tectonic stress distribution in the fracture vicinities. Examples of results of tectonic stress studies are given. Studies of tectonic stresses based on geological indicators are of methodological and practical importance.

Deflections in Lava Flow Directions Relative to Topography in the Tharsis Region: Indicators of Post-Flow Tectonic Motion

NASA Technical Reports Server (NTRS)

Chadwick, D. J.; Hughes, S. S.; Sakimoto, S. E. H.

2004-01-01

High-resolution topographic data for Mars from the Mars Orbiter Laser Altimeter (MOLA), and imagery from the Mars Orbiter Camera (MOC) and the Thermal Emission Imaging System (THEMIS) allow for the first accurate assessment of lava flow directions relative to topographic slopes in the Tharsis region. Tharisis has long been recognized as the dominant tectonic and volcanic province on the planet, with a complex geologic history. In this study, lava flow directions on Daedalia Planum, Syria Planum, Tempe Terra, and near the Tharsis Montes are compared with MOLA topographic contours to look for deviations of flow directions from the local slope direction. The topographic deviations identified in this study are likely due to Tharsis tectonic deformation that has modified the regional topography subsequent to the emplacement of the flows, and can be used to model the mechanisms and magnitudes of relatively recent tectonism in the region. A similar approach was used to identify possible postflow tectonic subsidence on the Snake River Plain in Idaho.

Deflections in Lava Flow Directions Relative to Topography in the Tharsis Region of Mars: Indications of Post-Flow Tectonic Motion

NASA Technical Reports Server (NTRS)

Chadwick, D. J.; Hughes, S. S.; Sakimoto, S. E. H.

2004-01-01

High-resolution topographic data from the Mars Orbiter Laser Altimeter (MOLA), and imagery from the Mars Orbiter Camera (MOC) and the Thermal Emission Imaging System (THEMIS) allow for the first accurate assessment of lava flow directions relative to topographic slopes in the Tharsis region. Tharisis has long been recognized as the dominant tectonic and volcanic province on the planet, with a complex geologic history. In this study, lava flow directions on Daedalia Planum, Syria Planum, Tempe Terra, and near the Tharsis Montes are compared with MOLA topographic contours to look for deviations of flow directions from the local slope direction. The topographic deviations identified in this study are likely due to Tharsis tectonic deformation that has modified the regional topography subsequent to the emplacement of the flows, and can be used to model the mechanisms and magnitudes of relatively recent tectonism in the region. A similar approach was used to identify possible post-flow tectonic subsidence on the Snake River Plain in Idaho.

The Influence of the Ufimian Tectonic Concentric Structure on the Hydrocarbon Migration and Ore Genesis

NASA Astrophysics Data System (ADS)

Filippov, V. A.

2018-01-01

The Ufimian tectonic concentric structure (UTC) is a regional structure with concentric and zonal structure of the internal gravity field. In the Neoproterozoic this structure was at higher hypsometric level relative to the Bashkir Meganticlinorium. The most significant uplift of this tectonic concentric structure happened at the beginning of the Karatau time ( 825 Ma) and was accompanied by the formation of a ring fractured zone, favorable for hydrocarbon migration from the Lower Riphean black shales. Due to this, bitumens with higher Mo content in the Neoproterozoic and Paleozoic deposits are confined spatially to this zone. The bitumenosity of the Neoproterozoic deposits on the southern slope of the Ufimian tectonic concentric structure could have contributed to the formation of complex Cu-Ag-Mo-Re ores (copper sands) at the upper boundary of terrigenous red deposits of the Zilmerdak Formation. Positive structures identified in the Neoproterozoic deposits near the margin of the Ufimian tectonic concentric structure are considered to be promising for searching for hydrocarbon fields.

Present tectonics of the southeast of Russia as seen from GPS observations

NASA Astrophysics Data System (ADS)

Shestakov, N. V.; Gerasimenko, M. D.; Takahashi, H.; Kasahara, M.; Bormotov, V. A.; Bykov, V. G.; Kolomiets, A. G.; Gerasimov, G. N.; Vasilenko, N. F.; Prytkov, A. S.; Timofeev, V. Yu.; Ardyukov, D. G.; Kato, T.

2011-02-01

The present tectonics of Northeast Asia has been extensively investigated during the last 12 yr by using GPS techniques. Nevertheless, crustal velocity field of the southeast of Russia near the northeastern boundaries of the hypothesized Amurian microplate has not been defined yet. The GPS data collected between 1997 February and 2009 April at sites of the regional geodynamic network were used to estimate the recent geodynamic activity of this area. The calculated GPS velocities indicate almost internal (between network sites) and external (with respect to the Eurasian tectonic plate) stability of the investigated region. We have not found clear evidences of any notable present-day tectonic activity of the Central Sikhote-Alin Fault as a whole. This fault is the main tectonic unit that determines the geological structure of the investigated region. The obtained results speak in favour of the existence of a few separate blocks and a more sophisticated structure of the proposed Amurian microplate in comparison with an indivisible plate approach.

Geology of the Venus equatorial region from Pioneer Venus radar imaging

NASA Technical Reports Server (NTRS)

Senske, D. A.; Head, James W.

1989-01-01

The surface characteristics and morphology of the equatorial region of Venus were first described by Masursky et al. who showed this part of the planet to be characterized by two topographic provinces, rolling plains and highlands, and more recently by Schaber who described and interpreted tectonic zones in the highlands. Using Pioneer Venus (PV) radar image data (15 deg S to 45 deg N), Senske and Head examined the distribution, characteristics, and deposits of individual volcanic features in the equatorial region, and in addition classified major equatorial physiographic and tectonic units on the basis of morphology, topographic signature, and radar properties derived from the PV data. Included in this classification are: plains (undivided), inter-highland tectonic zones, tectonically segmented linear highlands, upland rises, tectonic junctions, dark halo plains, and upland plateaus. In addition to the physiographic units, features interpreted as coronae and volcanic mountains have also been mapped. The latter four of the physiographic units along with features interpreted to be coronae.

Distinguishing between tectonic and lithologic controls on bedrock channel longitudinal profiles using cosmogenic 10Be erosion rates and channel steepness index

USGS Publications Warehouse

Cyr, Andrew J.; Granger, Darryl E.; Olivetti, Valerio; Molin, Paola

2014-01-01

Knickpoints in fluvial channel longitudinal profiles and channel steepness index values derived from digital elevation data can be used to detect tectonic structures and infer spatial patterns of uplift. However, changes in lithologic resistance to channel incision can also influence the morphology of longitudinal profiles. We compare the spatial patterns of both channel steepness index and cosmogenic 10Be-determined erosion rates from four landscapes in Italy, where the geology and tectonics are well constrained, to four theoretical predictions of channel morphologies, which can be interpreted as the result of primarily tectonic or lithologic controls. These data indicate that longitudinal profile forms controlled by unsteady or nonuniform tectonics can be distinguished from those controlled by nonuniform lithologic resistance. In each landscape the distribution of channel steepness index and erosion rates is consistent with model predictions and demonstrates that cosmogenic nuclide methods can be applied to distinguish between these two controlling factors.

The tectonics of Titan: Global structural mapping from Cassini RADAR

USGS Publications Warehouse

Liu, Zac Yung-Chun; Radebaugh, Jani; Harris, Ron A.; Christiansen, Eric H.; Neish, Catherine D.; Kirk, Randolph L.; Lorenz, Ralph D.; ,

2016-01-01

The Cassini RADAR mapper has imaged elevated mountain ridge belts on Titan with a linear-to-arcuate morphology indicative of a tectonic origin. Systematic geomorphologic mapping of the ridges in Synthetic Aperture RADAR (SAR) images reveals that the orientation of ridges is globally E–W and the ridges are more common near the equator than the poles. Comparison with a global topographic map reveals the equatorial ridges are found to lie preferentially at higher-than-average elevations. We conclude the most reasonable formation scenario for Titan’s ridges is that contractional tectonism built the ridges and thickened the icy lithosphere near the equator, causing regional uplift. The combination of global and regional tectonic events, likely contractional in nature, followed by erosion, aeolian activity, and enhanced sedimentation at mid-to-high latitudes, would have led to regional infilling and perhaps covering of some mountain features, thus shaping Titan’s tectonic landforms and surface morphology into what we see today.

Tectonic evolution of the terrestrial planets.

PubMed

Head, J W; Solomon, S C

1981-07-03

The style and evolution of tectonics on the terrestrial planets differ substantially. The style is related to the thickness of the lithosphere and to whether the lithosphere is divided into distinct, mobile plates that can be recycled into the mantle, as on Earth, or is a single spherical shell, as on the moon, Mars, and Mercury. The evolution of a planetary lithosphere and the development of plate tectonics appear to be influenced by several factors, including planetary size, chemistry, and external and internal heat sources. Vertical tectonic movement due to lithospheric loading or uplift is similar on all of the terrestrial planets and is controlled by the local thickness and rheology of the lithosphere. The surface of Venus, although known only at low resolution, displays features both similar to those on Earth (mountain belts, high plateaus) and similar to those on the smaller planets (possible impact basins). Improved understanding of the tectonic evolution of Venus will permit an evaluation of the relative roles of planetary size and chemistry in determining evolutionary style.

Applications of industrial engineering. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Yarbrough, Walthea V.

1992-01-01

Two separate and distinctly different projects are described within this paper: the stepping motion bearing tester, and the memo search and find project. The objective of the first project was to program the JSI Digital Servo Controller to control the motor using the stepping pattern prescribed by the AMSU-U2 Scan Profile. The objective of the second project was to develop a dBASE 3 Plus program that would allow the user to gain the necessary information to retrieve the memo(s) being sought upon supplying a word or group of words possibly found in the keyword list or upon supplying the author's name.

Superposed ridges of the Hesperia Planum area on Mars

NASA Technical Reports Server (NTRS)

Raitala, Jouko

1988-01-01

Mare ridges of the Hesperia Planum area form linear, reticular and circular structures. The main factors effective in mare ridge formation have been: (1) a large areal, or maybe even global, shortening and compression, (2) major crustal tectonics, and (3) the moderation of tectonic movements by the megaregolith discontinuity layer(s) between surface lavas and the bedrock leaving the compressional thrust to dominate over other fault movements in surface tectonics.

Calibration of Attenuation Structure in Eurasia to Improve Discrimination and Yield

DTIC Science & Technology

2010-09-01

and travel-times over large and tectonically complicated regions. As a result regional discrimination methods (e.g., high-frequency P/S, Ms:mb) and...a poor job of predicting both regional amplitudes and travel-times over large and tectonically complicated regions. As a result regional...regions. Earthquake-explosion discrimination using high-frequency regional P/S amplitude ratios over large and tectonically complicated regions can only

Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ry, Rexha Verdhora, E-mail: rexha.vry@gmail.com; Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id

Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment.more » We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger’s method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger’s result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location.« less

Meso-Cenozoic tectonic evolution of the SE Brazilian continental margin: Petrographic, kinematic and dynamic analysis of the onshore Araruama Lagoon Fault System

NASA Astrophysics Data System (ADS)

Souza, Pricilla Camões Martins de; Schmitt, Renata da Silva; Stanton, Natasha

2017-09-01

The Ararauama Lagoon Fault System composes one of the most prominent set of lineaments of the SE Brazilian continental margin. It is located onshore in a key tectonic domain, where the basement inheritance rule is not followed. This fault system is characterized by ENE-WSW silicified tectonic breccias and cataclasites showing evidences of recurrent tectonic reactivations. Based on field work, microtectonic, kinematic and dynamic analysis, we reconstructed the paleostresses in the region and propose a sequence of three brittle deformational phases accountable for these reactivations: 1) NE-SW dextral transcurrence; 2) NNW-SSE dextral oblique extension that evolved to NNW-SSE "pure" extension; 3) ENE-WSW dextral oblique extension. These phases are reasonably correlated with the tectonic events responsible for the onset and evolution of the SE onshore rift basins, between the Neocretaceous and Holocene. However, based on petrographic studies and supported by regional geological correlations, we assume that the origin of this fault system is older, related to the Early Cretaceous South Atlantic rifting. This study provides significant information about one of the main structural trends of the SE Brazilian continental margin and the tectonic events that controlled its segmentation, since the Gondwana rifting, and compartmentalization of its onshore sedimentary deposits during the Cenozoic.

Development of multiple unconformities during the Devonian-Carboniferous transition on parts of Laurussia

USGS Publications Warehouse

Ettensohn, F.R.; Pashin, J.C.

1997-01-01

The Devonian-Carboniferous transition on Laurussia was a time of diverse geologic activity associated with the assembly of Pangea, including episodes of Late Devonian glacial-eustatic lowstand and active orogeny on four margins. Six widespread unconformities are present in the Devonian-Carboniferous (Mississippian) interval on southern parts of Laurussia. We suggest that attention to the timing and plan of the unconformities may provide ways of discerning tectonic and climatic controls on their respective origins. Indeed, unconformities generated by pure eustasy are ideally of interregional extent, whereas unconformities generated by tectonism reflect more local factors associated with the evolution of sedimentary basins. Each of the six unconformities analyzed provides evidence for concurrent eustasy and tectonism. Glaciation was apparently the dominant factor driving the development of unconformities during the latest Devonian. During the Early Carboniferous, however, the volume of glacial ice available to drive eustasy was limited and, at times, tectonism may have been the source of a subordinate eustatic signal. Development of unconformities in southern Laurussia appear to be local manifestations of tectonic and climatic processes associated with supercontinent assembly. Thus, the time may be at hand for construction of a new global stratigraphic paradigm that is based on the plate tectonic supercycle affecting continentality and climate.

The Yilgarn Craton western Australia: A tectonic synthesis

NASA Technical Reports Server (NTRS)

Fripp, R. E. P.

1986-01-01

The Yilgarn Craton in Western Australia is one of the larger contiguous preserved Archaean crustal fragments, with an area of about 650,000 square kilometres. Of this, by area, about 70% is granitoid and 30% greenstone. The Craton is defined by the Darling Fault on its western margin, by Proterozoic deformation belts on its southern and northwestern margins, and by unconformable younger sediments on its eastern and northeastern margins. A regional geotectonic synthesis at a scale of 1:500,000 is being prepared. This is based largely upon the 1:250,000 scale mapping of the Geological Survey of Western Australia together with interpretation using geophysical data, mainly airborne magnetic surveys. On a regional basis the granitoids are classied as pre-, syn- and post-tectonic with respect to greenstone belt deformation. The post-tectonic granitoids yield Rb-Sr isochrons of about 2.6 b.y., close to Rb-Sr ages for the greenstones themselves which are up to about 2.8 b.y. old, although data for the latter is sparse. Contacts between earlier granitoids and greenstones which are not obscured by the post-tectonic granitoids are most commonly tectonic contacts, intensely deformed and with mylonitic fabrics. The general concensus however is that there is a pre-tectonic, pre-greenhouse sialic gneiss preserved in places. A discussion follows.

"Tectonic Petrameter," An Alternative Method to Teaching the Geologic Time Scale

NASA Astrophysics Data System (ADS)

Posner, E. S.

2011-12-01

I have over a decade of experience as a performance poet and am now a graduate student in the geosciences. I have created a performance poem / play script, "Tectonic Petrameter," as an alternative method of teaching the geologic time scale. "The Archean came next and it was a blast. Tectonic plates were smaller and they moved pretty fast. In an enthusiastic flash of ash, volcanic islands smashed together." The use of rhyme and rhythm presents a different and interdisciplinary approach to teaching Earth history that appeals to a wide range of learning styles and makes science fun, while clearly describing important concepts in geology and events in Earth history. "Now it's time to get down with the Coal Swamp Stomp! Tap your feet to the beat of the formation of peat like a plant plantation soaking up the bright heat." "Tectonic Petrameter" by itself is an illustrated spoken-word poem that leads audiences from all levels of scientific background on an excitingly educational journey through geologic time. I will perform my 10-minute memorized poem and present results from my ongoing study to assess the effectiveness of "Tectonic Petrameter" as a teaching tool in K-12 and introductory undergraduate classroom curricula. I propose that using "Tectonic Petrameter" as a performance piece and theatrical play script in K-12 and introductory undergraduate classrooms, as well as in broader community venues, may be an avenue for breaking down barriers related to teaching about Earth's long and complex history. Digital copies of "Tectonic Petrameter" will be made available to interested parties.

Playing jigsaw with Large Igneous Provinces—A plate tectonic reconstruction of Ontong Java Nui, West Pacific

NASA Astrophysics Data System (ADS)

Hochmuth, Katharina; Gohl, Karsten; Uenzelmann-Neben, Gabriele

2015-11-01

The three largest Large Igneous Provinces (LIP) of the western Pacific—Ontong Java, Manihiki, and Hikurangi Plateaus—were emplaced during the Cretaceous Normal Superchron and show strong similarities in their geochemistry and petrology. The plate tectonic relationship between those LIPs, herein referred to as Ontong Java Nui, is uncertain, but a joined emplacement was proposed by Taylor (2006). Since this hypothesis is still highly debated and struggles to explain features such as the strong differences in crustal thickness between the different plateaus, we revisited the joined emplacement of Ontong Java Nui in light of new data from the Manihiki Plateau. By evaluating seismic refraction/wide-angle reflection data along with seismic reflection records of the margins of the proposed "Super"-LIP, a detailed scenario for the emplacement and the initial phase of breakup has been developed. The LIP is a result of an interaction of the arriving plume head with the Phoenix-Pacific spreading ridge in the Early Cretaceous. The breakup of the LIP shows a complicated interplay between multiple microplates and tectonic forces such as rifting, shearing, and rotation. Our plate kinematic model of the western Pacific incorporates new evidence from the breakup margins of the LIPs, the tectonic fabric of the seafloor, as well as previously published tectonic concepts such as the rotation of the LIPs. The updated rotation poles of the western Pacific allow a detailed plate tectonic reconstruction of the region during the Cretaceous Normal Superchron and highlight the important role of LIPs in the plate tectonic framework.

A new plate tectonic concept for the eastern-most Mediterranean

NASA Astrophysics Data System (ADS)

Huebscher, C.; McGrandle, A.; Scaife, G.; Spoors, R.; Stieglitz, T.

2012-04-01

Owing to the seismogenic faults bordering the Levant-Sinai realm and the discovery of giant gas reservoirs in the marine Levant Basin the scientific interest in this tectonically complex setting increased in recent years. Here we provide a new model for the Levant Basin architecture and adjacent plate boundaries emphasizing the importance of industrial seismic data for frontier research in earth science. PSDM seismics, residual gravity and depth to basement maps give a clear line of evidence that the Levant Basin, formerly considered as a single tectonic entity, is divided into two different domains. Highly stretched continental crust in the southern domain is separated from deeper and presumably Tethyan oceanic crust in the north. A transform continuing from southwest Cyprus to the Carmel Fault in northern Israel is considered as the boundary. If this interpretation holds, the Carmel-Cyprus Transform represents a yet unknown continent-ocean boundary in the eastern Mediterranean, thus adding new constrains for the Mediterranean plate tectonic puzzle. The Eratosthenes Seamount, considered as the spearhead of incipient continental collision in the eastern Mediterranean, is interpreted as a carbonate platform that developed above a volcanic basement. NW-SE trending strike-slip faults are abundant in the entire Levant region. Since this trend also shapes the topography of the Levant hinterland including Quaternary deposits their recent tectonic activity is quite likely. Thus, our study supports previous studies which attributed the evolution of submarine canyons and Holocene triggering of mass failures not only to salt tectonics or depositional processes, but also to active plate-tectonics.

Tectonic and climatic control on evolution of rift lakes in the Central Kenya Rift, East Africa

NASA Astrophysics Data System (ADS)

Bergner, A. G. N.; Strecker, M. R.; Trauth, M. H.; Deino, A.; Gasse, F.; Blisniuk, P.; Dühnforth, M.

2009-12-01

The long-term histories of the neighboring Nakuru-Elmenteita and Naivasha lake basins in the Central Kenya Rift illustrate the relative importance of tectonic versus climatic effects on rift-lake evolution and the formation of disparate sedimentary environments. Although modern climate conditions in the Central Kenya Rift are very similar for these basins, hydrology and hydrochemistry of present-day lakes Nakuru, Elmenteita and Naivasha contrast dramatically due to tectonically controlled differences in basin geometries, catchment size, and fluvial processes. In this study, we use eighteen 14C and 40Ar/ 39Ar dated fluvio-lacustrine sedimentary sections to unravel the spatiotemporal evolution of the lake basins in response to tectonic and climatic influences. We reconstruct paleoclimatic and ecological trends recorded in these basins based on fossil diatom assemblages and geologic field mapping. Our study shows a tendency towards increasing alkalinity and shrinkage of water bodies in both lake basins during the last million years. Ongoing volcano-tectonic segmentation of the lake basins, as well as reorganization of upstream drainage networks have led to contrasting hydrologic regimes with adjacent alkaline and freshwater conditions. During extreme wet periods in the past, such as during the early Holocene climate optimum, lake levels were high and all basins evolved toward freshwater systems. During drier periods some of these lakes revert back to alkaline conditions, while others maintain freshwater characteristics. Our results have important implications for the use and interpretation of lake sediment as climate archives in tectonically active regions and emphasize the need to deconvolve lacustrine records with respect to tectonics versus climatic forcing mechanisms.

Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska

NASA Technical Reports Server (NTRS)

SauberRosenberg, Jeanne M.; Molnia, Bruce F.

2003-01-01

Across southern Alaska the northwest directed subduction of the Pacific plate is accompanied by accretion of the Yakutat terrane to continental Alaska. This has led to high tectonic strain rates and dramatic topographic relief of more than 5000 meters within 15 km of the Gulf of Alaska coast. The glaciers of this area are extensive and include large glaciers undergoing wastage (glacier retreat and thinning) and surges. The large glacier ice mass changes perturb the tectonic rate of deformation at a variety of temporal and spatial scales. We estimated surface displacements and stresses associated with ice mass fluctuations and tectonic loading by examining GPS geodetic observations and numerical model predictions. Although the glacial fluctuations perturb the tectonic stress field, especially at shallow depths, the largest contribution to ongoing crustal deformation is horizontal tectonic strain due to plate convergence. Tectonic forces are thus the primary force responsible for major earthquakes. However, for geodetic sites located < 10-20 km from major ice mass fluctuations, the changes of the solid Earth due to ice loading and unloading are an important aspect of interpreting geodetic results. The ice changes associated with Bering Glacier s most recent surge cycle are large enough to cause discernible surface displacements. Additionally, ice mass fluctuations associated with the surge cycle can modify the short-term seismicity rates in a local region. For the thrust faulting environment of the study region a large decrease in ice load may cause an increase in seismic rate in a region close to failure whereas ice loading may inhibit thrust faulting.

Tectonic stress pattern in the Chinese Mainland from the inversion of focal mechanism data

NASA Astrophysics Data System (ADS)

Wei, Ju; Weifeng, Sun; Xiaojing, Ma

2017-04-01

The tectonic stress pattern in the Chinese Mainland and kinematic models have been subjected to much debate. In the past several decades, several tectonic stress maps have been figured out; however, they generally suffer a poor time control. In the present study, 421 focal mechanism data up to January 2010 were compiled from the Global/Harvard CMT catalogue, and 396 of them were grouped into 23 distinct regions in function of geographic proximity. Reduced stress tensors were obtained from formal stress inversion for each region. The results indicated that, in the Chinese Mainland, the directions of maximum principal stress were ˜NE-SW-trending in the northeastern region, ˜NEE-SWW-trending in the North China region, ˜N-S-trending in western Xinjiang, southern Tibet and the southern Yunnan region, ˜NNE-SSW-trending in the northern Tibet and Qinghai region, ˜NW-SE-trending in Gansu region, and ˜E-W-trending in the western Sichuan region. The average tectonic stress regime was strike-slip faulting (SS) in the eastern Chinese Mainland and northern Tibet region, normal faulting (NF) in the southern Tibet, western Xinjiang and Yunnan region, and thrust faulting (TF) in most regions of Xinjiang, Qinghai and Gansu. The results of the present study combined with GPS velocities in the Chinese Mainland supported and could provide new insights into previous tectonic models (e.g., the extrusion model). From the perspective of tectonics, the mutual actions among the Eurasian plate, Pacific plate and Indian plate caused the present-day tectonic stress field in the Chinese Mainland.

On the Evolution of Terrestrial Planets: Implications of Evolutionary Paths and Evolving Lid-States

NASA Astrophysics Data System (ADS)

Weller, M. B.; Lenardic, A.

2015-12-01

Growing geodynamic and geochemical evidence suggests that plate tectonics may not have operated on the early Earth, with both the timing of its onset and the length of its activity far from certain [e.g., 1, 2, and references therein]. Accordingly, information from current observations and processes have the potential of sampling portions of the Earth that has both formed under and been modified by differing tectonic regimes. Here we use coupled 3D mantle convection and planetary tectonics simulations to explore evolutionary paths and planetary tectonic regimes. Early in the geologic lifetime of a terrestrial planet, high mantle temperatures favour stagnant-lids. As radiogenics decay, an initial stagnant-lid may yield into a high temperature mobile-lid state. The transition from an initial stagnant-lid is a function of yield strength, in addition to both internal and surface temperatures. Each lid-state has specific diagnostics and implications for internal parameters, and consequently planetary evolution. The implication within this framework is that a system with a different thermal evolution has the potential to migrate through tectonic regimes at the same 'thermal time' (e.g. temperature), but very different 'temporal times'. This indicate that multiple modes of convection and surface tectonics can potentially operate on a single planetary body at different times in its evolution, as consequence of changing internal parameters, surface temperatures, and differing thermal histories. We will discuss the implications of terrestrial worlds that can alternate, and be offset between multiple tectonic states over giga-year timescales. [1] O'Neill et. al. (2013b) Geol. Soc. London; [2] Weller et al. (2015) EPSL

The Black Mountain tectonic zone--a reactivated northeast-trending crustal shear zone in the Yukon-Tanana Upland of east-central Alaska: Chapter D in Recent U.S. Geological Survey studies in the Tintina Gold Province, Alaska, United States, and Yukon, Canada--results of a 5-year project

USGS Publications Warehouse

O'Neill, J. Michael; Day, Warren C.; Alienikoff, John N.; Saltus, Richard W.; Gough, Larry P.; Day, Warren C.

2007-01-01

The Black Mountain tectonic zone in the YukonTanana terrane of east-central Alaska is a belt of diverse northeast-trending geologic features that can been traced across Black Mountain in the southeast corner of the Big Delta 1°×3° degree quadrangle. Geologic mapping in the larger scale B1 quadrangle of the Big Delta quadrangle, in which Black Mountain is the principal physiographic feature, has revealed a continuous zone of normal and left-lateral strikeslip high-angle faults and shear zones, some of which have late Tertiary to Quaternary displacement histories. The tectonic zone includes complexly intruded wall rocks and intermingled apophyses of the contiguous mid-Cretaceous Goodpaster and Mount Harper granodioritic plutons, mafic to intermediate composite dike swarms, precious metal mineralization, early Tertiary volcanic activity and Quaternary fault scarps. These structures define a zone as much as 6 to 13 kilometers (km) wide and more than 40 km long that can be traced diagonally across the B1 quadrangle into the adjacent Eagle 1°×3° quadrangle to the east. Recurrent activity along the tectonic zone, from at least mid-Cretaceous to Quaternary, suggests the presence of a buried, fundamental tectonic feature beneath the zone that has influenced the tectonic development of this part of the Yukon-Tanana terrane. The tectonic zone, centered on Black Mountain, lies directly above a profound northeast-trending aeromagnetic anomaly between the Denali and Tintina fault systems. The anomaly separates moderate to strongly magnetic terrane on the northwest from a huge, weakly magnetic terrane on the southeast. The tectonic zone is parallel to the similarly oriented left-lateral, strike-slip Shaw Creek fault zone 85 km to the west.

Tectonic map of Uruguay

NASA Astrophysics Data System (ADS)

Sanchez Bettucci, L.; Oyhantcabal, P.

2008-05-01

A compilation of available data about the geology of Uruguay allowed the definition of its main events and tectonic units. Based on a critical revision of different tectonic hypothesis found in the literature, a parsimonious tectonic evolution schema is presented, in the context of Western Gondwana. The tectonic map illustrates the general features of the structure and main tectonic units of Uruguay. The Precambrian shield, cropping out in the South and Southeast of the country is an Archean to Paleoprtoerozoic basement divided in three main tectonostratigraphic terrranes: the Piedra Alta (PAT) a juvenile Paleoproterozoic unit not reworked by later events; the Nico Pérez (NPT) a complex unit composed of several blocks where Archean to Mesoproterozoic events are recognised. The NPT was strongly reworked by Neoproterozoic (Brasiliano) orogeny. The Dom Feliciano Belt cropping out in eastern Uruguay is related to Western Gondwana amalgamation. Different tectonic settings are considered: pre-Brasiliano Basement inliers; supracrustal successions representing the evolution from a back- arc to a foreland basin; a magmatic arc; and post-collisional basins and related magmatism. In lower Paleozoic the Paraná foreland basin was generated as a consequence of orogenic events. The sedimentary successions in Uruguay include continental to shallow marine deposits where the influence of carboniferous to Permian glacial episode is recorded. The Mesozoic record is characterised by the influence of extension related to the break-up of Gondwana and the formation of the Atlantic Ocean: huge amounts of tholeiitic basalt were erupted (near 30.000 km3 in Uruguay), followed by cretaceous sediments in the northern area of the country while in the south-east, bimodal magmatism and sediments of the same age are associated to rift basins. The Cenozoic is characterised by tectonic quiescence. Subsidence is only observed in the western region (Chaco-Paraná Basin) and in the east (Laguna Merín Basin).

Hot-field tectonics

NASA Astrophysics Data System (ADS)

Zonenshain, L. P.; Kuzmin, M. I.; Bocharova, N. Yu.

1991-12-01

Intraplate, hot spot related volcanic occurrences do not have a random distribution on the Earth's surface. They are concentrated in two large regions (up to 10,000 km in diameter), the Pacific and the African, and two smaller areas (2000-3000 km in diameter), the Central Asian and the Tasmanian. These regions are considered as manifestations of hot fields in the mantle, whereas the regions lying in between are expressions of cold fields in the mantle. Large-scale anomalies coincide with the hot fields: topographic swells, geoid highs, uplifts of the "asthenospheric table", inferred heated regions in the lowermost mantle according to seismic tomographic images, geochemical anomalies showing the origin of volcanics from undepleted mantle sources. Hot fields are relatively stable features, having remained in the same position on the Earth's surface during the last 120 Ma, although they have other configurations and other positions in the Late Paleozoic and Early Mesozoic. Available data show that two main hot fields (Pacific and African) are possibly moving one with respect to the other, converging along the Eastern Pacific subduction system and diverging along that of the Western Pacific. If so, well-known differences between these subduction systems can also be connected with related displacement of the hot fields. Hot fields are assumed to correspond to upwelling branches of mantle and rather deep mantle convection, and cold fields to downwelling branches. Thus, hot fields can be regarded as expressions of deeper tectonics, comparative to the plate tectonics, which is operating in the upper layers of the Earth. We call it hot-field tectonics. Plate tectonics is responsible for the opening and closure of oceans and for the formation of orogenic belts, whereas hot-field tectonics accounts for a larger cyclicity of the Earth's evolution and for amalgamation and break up of Pangea-type supercontinents. Hot-field tectonics seems to be the only process to have existed on all of the terrestrial planets. We speculate that hot-field tectonics governs the global geodynamics of the Earth.

Viscoelastic Lithosphere Response and Stress Memory of Tectonic Force History (Invited)

NASA Astrophysics Data System (ADS)

Kusznir, N. J.

2009-12-01

While great attention is often paid to the details of creep deformation mechanisms, brittle failure and their compositional controls when predicting the response of lithosphere to tectonic forces, the lithosphere’s elastic properties are usually neglected; a viscous rheology alone is often used to predict the resulting distribution of stress with depth or to determine lithosphere strength. While this may simplify geodynamic modelling of lithosphere response to tectonic processes, the omission of the elastic properties can often give misleading or false predictions. The addition of the elastic properties of lithosphere material in the form of a visco-elastic rheology results is a fundamentally different lithosphere response. This difference can be illustrated by examining the application of horizontal tectonic force to a section of lithosphere incorporating the brittle-visco-elastic response of each infinitesimal lithosphere layer with temperature and stress dependent viscous rheology. The transient response of a visco-elastic lithosphere to a constant applied tectonic force and the resulting distribution of stress with depth are substantially different from that predicted by a viscous lithosphere model, with the same lithosphere composition and temperature structure, subjected to a constant lateral strain rate. For visco-elastic lithosphere subject to an applied horizontal tectonic force, viscous creep in the lower crust and mantle leads to stress decay in these regions and to stress amplification in the upper lithosphere through stress redistribution. Cooling of lithosphere with a visco-elastic rheology results in thermal stresses which, as a consequence of stress dissipation by creep and brittle failure, results in a complex and sometimes counter-intuitive distribution of stress with depth. This can be most clearly illustrated for the cooling of oceanic lithosphere, however similar or more complex behaviour can be expected to occur for continental lithosphere. The application of changes in applied tectonic force with time to a visco-elastic lithosphere model results in reversals in the sign of stress with depth as a consequence of the “memory” of past stress dissipation by creep and brittle deformation. Because of this “memory”, locally stress polarity may be opposite to that of the current applied tectonic force. A lithosphere with viscous rheology displays no such “memory” of the applied tectonic stress history. The stress “memory” of lithosphere with visco-elastic rheology to its history of applied tectonic force, heating and cooling adds to its effective rheological complexity, particularly for continental lithosphere.

Calculation of Tectonic Strain Release from an Explosion in a Three-Dimensional Stress Field

NASA Astrophysics Data System (ADS)

Stevens, J. L.; O'Brien, M. S.

2012-12-01

We have developed a 3D nonlinear finite element code designed for calculation of explosions in 3D heterogeneous media and have incorporated the capability to perform explosion calculations in a prestressed medium. The effect of tectonic prestress on explosion-generated surface waves has been discussed since the 1960's. In most of these studies tectonic release was described as superposition of a tectonic source modeled as a double couple, multipole or moment tensor, plus a point explosion source. The size of the tectonic source was determined by comparison with the observed Love waves and the Rayleigh wave radiation pattern. Day et al. (1987) first attempted to perform numerical modeling of tectonic release through an axisymmetric calculation of the explosion Piledriver. To the best of our knowledge no one has previously performed numerical calculations for an explosion in a three-dimensional stress field. Calculation of tectonic release depends on a realistic representation of the stress state in the earth. In general the vertical stress is equal to the overburden weight of the material above at any given point. The horizontal stresses may be larger or smaller than this value up to the point where failure due to frictional sliding relieves the stress. In our calculations, we use the normal overburden calculation to determine the vertical stress, and then modify the horizontal stresses to some fraction of the frictional limit. This is the initial stable state of the calculation prior to introduction of the explosion. Note that although the vertical stress is still equivalent to the overburden weight, the pressure is not, and it may be either increased or reduced by the tectonic stresses. Since material strength increases with pressure, this also can substantially affect the seismic source. In general, normal faulting regimes will amplify seismic signals, while reverse faulting regimes will decrease seismic signals; strike-slip regimes may do either. We performed a 3D calculation of the Shoal underground nuclear explosion including tectonic prestress. Shoal was a 12.5 kiloton nuclear explosion detonated near Fallon, Nevada. This event had strong heterogeneity in near field waveforms and is in a region under primarily extensional tectonic stress. There were three near-field shot level recording stations located in three directions each at about 590 meters from the shot. Including prestress consistent with the regional stress field causes variations in the calculated near-field waveforms similar to those observed in the Shoal data.

Differential preservation in the geologic record of intraoceanic arc sedimentary and tectonic processes

USGS Publications Warehouse

Draut, Amy; Clift, Peter D.

2013-01-01

Records of ancient intraoceanic arc activity, now preserved in continental suture zones, are commonly used to reconstruct paleogeography and plate motion, and to understand how continental crust is formed, recycled, and maintained through time. However, interpreting tectonic and sedimentary records from ancient terranes after arc–continent collision is complicated by preferential preservation of evidence for some arc processes and loss of evidence for others. In this synthesis we examine what is lost, and what is preserved, in the translation from modern processes to the ancient record of intraoceanic arcs. Composition of accreted arc terranes differs as a function of arc–continent collision geometry. ‘Forward-facing’ collision can accrete an oceanic arc on to either a passive or an active continental margin, with the arc facing the continent and colliding trench- and forearc-side first. In a ‘backward-facing’ collision, involving two subduction zones with similar polarity, the arc collides backarc-first with an active continental margin. The preservation of evidence for contemporary sedimentary and tectonic arc processes in the geologic record depends greatly on how well the various parts of the arc survive collision and orogeny in each case. Preservation of arc terranes likely is biased towards those that were in a state of tectonic accretion for tens of millions of years before collision, rather than tectonic erosion. The prevalence of tectonic erosion in modern intraoceanic arcs implies that valuable records of arc processes are commonly destroyed even before the arc collides with a continent. Arc systems are most likely to undergo tectonic accretion shortly before forward-facing collision with a continent, and thus most forearc and accretionary-prism material in ancient arc terranes likely is temporally biased toward the final stages of arc activity, when sediment flux to the trench was greatest and tectonic accretion prevailed. Collision geometry and tectonic erosion vs. accretion are important controls on the ultimate survival of material from the trench, forearc, arc massif, intra-arc basins, and backarc basins, and thus on how well an ancient arc terrane preserves evidence for tectonic processes such as subduction of aseismic ridges and seamounts, oblique plate convergence, and arc rifting. Forward-facing collision involves substantial recycling, melting, and fractionation of continent-derived material during and after collision, and so produces melts rich in silica and incompatible trace elements. As a result, forward-facing collision can drive the composition of accreted arc crust toward that of average continental crust.

The tectonic evolution of the Irtysh tectonic belt: New zircon U-Pb ages of arc-related and collisional granitoids in the Kalaxiangar tectonic belt, NW China

NASA Astrophysics Data System (ADS)

Hong, Tao; Klemd, Reiner; Gao, Jun; Xiang, Peng; Xu, Xing-Wang; You, Jun; Wang, Xin-Shui; Wu, Chu; Li, Hao; Ke, Qiang

2017-02-01

Precise geochronological constraints of the Irtysh tectonic belt situated between the Saur Island Arc and the Altay Terrane are crucial to a better understanding of the tectonic evolution of the Central Asian Orogenic Belt (CAOB). Recently, we discovered repeatedly deformed arc-related and collisional granitoids in the Kalaxiangar tectonic belt (KTB), which is located in the eastern part of the Irtysh tectonic belt. In this study, we report new whole-rock geochemical, zircon U-Pb and Hf isotopic data of the arc-related and collisional granitoids. Our data reveal that 1) arc-related granodioritic porphyries formed at ca. 382-374 Ma. Recrystallized zircon grains from a (ultra-)mylonitic granodiorite of the Laoshankou zone in the southern KTB display a U-Pb age of ca. 360 Ma; 2) syn-collisional granodioritic porphyries, which distribute along faults and parallel to the cleavage, were emplaced at ca. 367-356 Ma, with εHf(t) values varying from + 7.8 to + 14.2 and Hf model ages from 873 to 459 Ma; 3) a post-collisional A-type granodioritic porphyry, which crosscuts the NW-NNW trending schistosity of the metasedimentary country rocks at a low angle, has an age of ca. 324-320 Ma, while the εHf(t) values range from + 7.6 to + 14.4 with Hf model ages from 850 to 416 Ma; 4) post-collisional strike-slip A-type granite dykes, exposed along strike-slip faults, gave ages between 287 and 279 Ma, whereas the εHf(t) values range from + 4.9 to + 12.7 and the Hf model ages from 995 to 500 Ma; and 5) A-type biotite granite dykes, which intruded along conjugate tension joints, have ages of 274-271 Ma, and εHf(t) values from + 1.5 to + 13.2 with Hf model ages from 1196 to 454 Ma. Consequently, we propose that the collision between the Saur Island Arc and the Altay Terrane occurred in the Early Carboniferous (ca. 367-356 Ma) and the subsequent post-collisional tectonic process continued to the Late Carboniferous (ca. 324-320 Ma). It is further suggested that the Irtysh tectonic belt underwent large-scale strike-slip deformation during the mid-Permian between 287 and 279 Ma. The termination of the Irtysh tectonic belt orogeny is thought to have also occurred during the mid-Permian between 274 and 271 Ma.

Evaluation of Dengue-Related Health Information on the Internet

PubMed Central

Rao, Navya R.; Mohapatra, Manaswini; Mishra, Swayamprabha; Joshi, Ashish

2012-01-01

The objective of this study was to examine the quality of dengue-related health information on the Internet. Three raters used the keyword dengue to search the Google, Yahoo!, and Bing search engines during August 2011. The first 20 websites from each search engine were examined for a total of 60 sites. Duplicate, nonfunctional, non-English, and nonoperational websites were excluded from the study, resulting in 36 sites for final analysis. The 16-item DISCERN tool was used to evaluate the quality of dengue-related health information on the Internet. Chi-square analysis and analysis of variance were performed to compare the DISCERN scores. Inter-rater reliability analysis showed significant differences in the level of agreement among the three raters. The 36 unique websites were categorized into .com, .edu, .gov, .org, and other sites. The .com sites had the lowest DISCERN scores. Educating consumers on how to find and recognize valid health information on the Internet may lead to better informed decision making. PMID:22783151

Aerogel Blanket Insulation Materials for Cryogenic Applications

NASA Technical Reports Server (NTRS)

Coffman, B. E.; Fesmire, J. E.; White, S.; Gould, G.; Augustynowicz, S.

2009-01-01

Aerogel blanket materials for use in thermal insulation systems are now commercially available and implemented by industry. Prototype aerogel blanket materials were presented at the Cryogenic Engineering Conference in 1997 and by 2004 had progressed to full commercial production by Aspen Aerogels. Today, this new technology material is providing superior energy efficiencies and enabling new design approaches for more cost effective cryogenic systems. Aerogel processing technology and methods are continuing to improve, offering a tailor-able array of product formulations for many different thermal and environmental requirements. Many different varieties and combinations of aerogel blankets have been characterized using insulation test cryostats at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Detailed thermal conductivity data for a select group of materials are presented for engineering use. Heat transfer evaluations for the entire vacuum pressure range, including ambient conditions, are given. Examples of current cryogenic applications of aerogel blanket insulation are also given. KEYWORDS: Cryogenic tanks, thermal insulation, composite materials, aerogel, thermal conductivity, liquid nitrogen boil-off

Web information retrieval based on ontology

NASA Astrophysics Data System (ADS)

Zhang, Jian

2013-03-01

The purpose of the Information Retrieval (IR) is to find a set of documents that are relevant for a specific information need of a user. Traditional Information Retrieval model commonly used in commercial search engine is based on keyword indexing system and Boolean logic queries. One big drawback of traditional information retrieval is that they typically retrieve information without an explicitly defined domain of interest to the users so that a lot of no relevance information returns to users, which burden the user to pick up useful answer from these no relevance results. In order to tackle this issue, many semantic web information retrieval models have been proposed recently. The main advantage of Semantic Web is to enhance search mechanisms with the use of Ontology's mechanisms. In this paper, we present our approach to personalize web search engine based on ontology. In addition, key techniques are also discussed in our paper. Compared to previous research, our works concentrate on the semantic similarity and the whole process including query submission and information annotation.

Community Involvement in Enhancing the Global Change Master Directory (GCMD) Controlled Vocabularies (Keywords)

NASA Technical Reports Server (NTRS)

Stevens, T.; Ritz, S.; Aleman, A.; Genazzio, M.; Morahan, M.; Wharton, S.

2016-01-01

NASA's Global Change Master Directory (GCMD) develops and expands a hierarchical set of controlled vocabularies (keywords) covering the Earth sciences and associated information (data centers, projects, platforms, instruments, etc.). The purpose of the keywords is to describe Earth science data and services in a consistent and comprehensive manner, allowing for the precise searching of metadata and subsequent retrieval of data and services. The keywords are accessible in a standardized SKOSRDFOWL representation and are used as an authoritative taxonomy, as a source for developing ontologies, and to search and access Earth Science data within online metadata catalogues. The keyword development approach involves: (1) receiving community suggestions, (2) triaging community suggestions, (3) evaluating the keywords against a set of criteria coordinated by the NASA ESDIS Standards Office, and (4) publication/notification of the keyword changes. This approach emphasizes community input, which helps ensure a high quality, normalized, and relevant keyword structure that will evolve with users changing needs. The Keyword Community Forum, which promotes a responsive, open, and transparent processes, is an area where users can discuss keyword topics and make suggestions for new keywords. The formalized approach could potentially be used as a model for keyword development.

Extraction of Protein-Protein Interaction from Scientific Articles by Predicting Dominant Keywords.

PubMed

Koyabu, Shun; Phan, Thi Thanh Thuy; Ohkawa, Takenao

2015-01-01

For the automatic extraction of protein-protein interaction information from scientific articles, a machine learning approach is useful. The classifier is generated from training data represented using several features to decide whether a protein pair in each sentence has an interaction. Such a specific keyword that is directly related to interaction as "bind" or "interact" plays an important role for training classifiers. We call it a dominant keyword that affects the capability of the classifier. Although it is important to identify the dominant keywords, whether a keyword is dominant depends on the context in which it occurs. Therefore, we propose a method for predicting whether a keyword is dominant for each instance. In this method, a keyword that derives imbalanced classification results is tentatively assumed to be a dominant keyword initially. Then the classifiers are separately trained from the instance with and without the assumed dominant keywords. The validity of the assumed dominant keyword is evaluated based on the classification results of the generated classifiers. The assumption is updated by the evaluation result. Repeating this process increases the prediction accuracy of the dominant keyword. Our experimental results using five corpora show the effectiveness of our proposed method with dominant keyword prediction.

Tectonic History of the Terrestrial Planets

NASA Technical Reports Server (NTRS)

Solomon, Sean C.

1993-01-01

The topics covered include the following: patterns of deformation and volcanic flows associated with lithospheric loading by large volcanoes on Venus; aspects of modeling the tectonics of large volcanoes on the terrestrial planets; state of stress, faulting, and eruption characteristics of large volcanoes on Mars; origin and thermal evolution of Mars; geoid-to-topography ratios on Venus; a tectonic resurfacing model for Venus; the resurfacing controversy for Venus; and the deformation belts of Lavinia Planitia.

Tectonic map of the Arabian Peninsula

USGS Publications Warehouse

Brown, Glen F.

1972-01-01

This tectonic map of the Arabian peninsula, prepared for the Audi Arabian Ministry of Petroleum and Mineral Resource, is the first of a series of peninsular maps that attempt to show regional features. Much recent information resulting from detailed geologic mapping notably within the Arabian craton, from geophysical surveys, both airborne and oceanographic in adjacent seas, from deep exploratory drilling, and from photography from the Gemini and Apollo space programs, has been used in the tectonic evaluation.

Tectonic patterns and regional stresses near Venusian coronae

NASA Astrophysics Data System (ADS)

Cyr, K. E.; Melosh, H. J.

1993-04-01

A stress analysis of tectonic patterns near Venusian coronae is reported. Combined local corona stresses and uniform regional stresses are used to predict patterns of surface tectonic features. The patterns are compared to those of coronae on Magellan images to determine the regional stress and elastic lithospheric thickness about the coronae. Regional stresses of 0.1-0.6 kbar and elastic lithospheric thicknesses of 10 +/- 5 km are estimated for three specific coronae.

Burke new Tectonics editor

NASA Astrophysics Data System (ADS)

Kevin C. Burke, National Academy of Sciences/ National Research Council (NAS/NRC), assumed responsibilities as Editor in Chief of the American Geophysical Union (AGU) journal Tectonics at the beginning of 1990, taking over from Raymond A. Price, Queens University, Kingston, Ontario. Asger Berthelsen, University of Copenhagen, Denmark, continues as the European Editor, and Paul F. Hoffman, Geological Society of Canada, assumes the task of North American Editor. Tectonics is a joint publication of AGU and the European Geophysical Society.

Refinement of Regional Distance Seismic Moment Tensor and Uncertainty Analysis for Source-Type Identification

DTIC Science & Technology

2011-09-01

a NSS that lies in this negative explosion positive CLVD quadrant due to the large degree of tectonic release in this event that reversed the phase...Mellman (1986) in their analysis of fundamental model Love and Rayleigh wave amplitude and phase for nuclear and tectonic release source terms, and...1986). Estimating explosion and tectonic release source parameters of underground nuclear explosions from Rayleigh and Love wave observations, Air

Regional tectonic analysis of Venus equatorial highlands and comparison with Earth-based Magellan radar images

NASA Technical Reports Server (NTRS)

Williams, David R.; Wetherill, George

1993-01-01

Research on regional tectonic analysis of Venus equatorial highlands and comparison with earth-based and Magellan radar images is presented. Over the past two years, the tectonic analysis of Venus performed centered on global properties of the planet, in order to understand fundamental aspects of the dynamics of the mantle and lithosphere of Venus. These include studies pertaining to the original constitutive and thermal character of the planet, as well as the evolution of Venus through time, and the present day tectonics. Parameterized convection models of the Earth and Venus were developed. The parameterized convection code was reformulated to model Venus with an initially hydrous mantle to determine how the cold-trap could affect the evolution of the planet.

CHARACTER AND REGIONAL SIGNIFICANCE OF GREAT FALLS TECTONIC ZONE, EAST-CENTRAL IDAHO AND WEST-CENTRAL MONTANA.

USGS Publications Warehouse

O'Neill, J. Michael; Lopez, David A.

1985-01-01

The Great Falls tectonic zone, here named, is a belt of diverse northeast-trending geologic features that can be traced from the Idaho batholith in the Cordilleran miogeocline, across thrust-belt structures and basement rocks of west-central and southwestern Montana, through cratonic rocks of central Montana, and into southwestern-most Saskatchewan, Canada. Geologic mapping in east-central Idaho and west-central Montana has outlined a continuous zone of high-angle faults and shear zones. Recurrent fault movement in this zone and strong structural control over igneous intrusion suggest a fundamental tectonic feature that has influenced the tectonic development of the Idaho-Montana area from a least middle Proterozoic time to the present. Refs.

A Century of Geology-Curriculum Response to Society: A Case Study at Oregon State University

NASA Astrophysics Data System (ADS)

Grunder, A.; Johnson, J. A.

2014-12-01

Over the past century, the geology curriculum at Oregon State University has remained constant in some areas and changed in others in response to internal (faculty and university) and external (economic, and intellectual) drivers. A decadal summary of 100 years of the geology curriculum at Oregon State University reveals socio-economic patterns. From 1913, when the School of Mines was established, to 1932, when it was dismembered, the geology curriculum was designed in support mining engineering. In that time, the geology department (est. 1914) moved from the School of Mines to the School of Science. Several decades of paleontology-intensive curriculum followed under the leadership of noted paleontologist Earl Packard, as dean and chair. The curriculum transitioned from support of the oil industry in the 60s and 70s, with a strong field emphasis engendered by "Doc" Wilkinson, to increased structure and tectonics emphasis in response to the tectonic revolution under the leadership of structural geologist Robert Yeats. In the last few decades the program has grown diverse in environmental and climatic interests. The early curriculum required a three-course series in determinative mineralogy plus petrography and 3 courses in petrology (igneous, sedimentary and metamorphic), making a core of seven; we require 3 courses today. Like all students in the School of Mines, those with the geology specialization were required to take a field course in surveying and to spend several summer months working in the mining industry. This strong field tradition persisted through time with an introductory field methods class coupled with a summer field camp. The total number of weeks dedicated to field classes, excluding the work experience requirement, has varied from as high as 12 credit-hours to the present 6 (quarters basis). On the other hand, increased short field experiences are reflected by incorporation of more field trips in nearly all courses since the 80's, fostered by accessible transportation. General education courses delivered by geology faculty have mimicked these changes, from early service courses in basic geology for engineering, mining and agriculture to a diverse slate of courses from basic geology to natural hazards and climate.

Design implications for task-specific search utilities for retrieval and re-engineering of code

NASA Astrophysics Data System (ADS)

Iqbal, Rahat; Grzywaczewski, Adam; Halloran, John; Doctor, Faiyaz; Iqbal, Kashif

2017-05-01

The importance of information retrieval systems is unquestionable in the modern society and both individuals as well as enterprises recognise the benefits of being able to find information effectively. Current code-focused information retrieval systems such as Google Code Search, Codeplex or Koders produce results based on specific keywords. However, these systems do not take into account developers' context such as development language, technology framework, goal of the project, project complexity and developer's domain expertise. They also impose additional cognitive burden on users in switching between different interfaces and clicking through to find the relevant code. Hence, they are not used by software developers. In this paper, we discuss how software engineers interact with information and general-purpose information retrieval systems (e.g. Google, Yahoo!) and investigate to what extent domain-specific search and recommendation utilities can be developed in order to support their work-related activities. In order to investigate this, we conducted a user study and found that software engineers followed many identifiable and repeatable work tasks and behaviours. These behaviours can be used to develop implicit relevance feedback-based systems based on the observed retention actions. Moreover, we discuss the implications for the development of task-specific search and collaborative recommendation utilities embedded with the Google standard search engine and Microsoft IntelliSense for retrieval and re-engineering of code. Based on implicit relevance feedback, we have implemented a prototype of the proposed collaborative recommendation system, which was evaluated in a controlled environment simulating the real-world situation of professional software engineers. The evaluation has achieved promising initial results on the precision and recall performance of the system.

Trends and opportunities in seismology. [Asilomar, California, January 3--9, 1976

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1977-01-01

Thirty-five experts in the fields of geology, geophysics, and engineering, from academia, government, and industry, were invited to participate in a workshop and address the many problems of national and global concern that require seismological expertise for their solutions. This report reviews the history, accomplishments, and status of seismology; assesses changing trends in seismological research and applications; and recommends future directions in the light of these changes and of the growing needs of society in areas in which seismology can make significant contributions. The first part of the volume discusses areas of opportunity (understanding earthquakes and reducing their hazards; exploration,more » energy, and resources; understanding the earth and planets) and realizing the benefits (the roles of Federal, state, and local governments, industry, and universities). The second part, Background and Progress, briefly considers each of the following topics: the birth and early growth of seismology, nuclear test monitoring and its scientific ramifications, instrumentation and data processing, geodynamics and plate tectonics, theoretical seismology, structure and composition of the earth, exploration seismology, seismic exploration for minerals, earthquake source mechanism studies, engineering seismology, strong ground motion and related earthquake hazards, volcanoes, tsunamis, planetary seismology, and international aspects of seismology. 26 figures. (RWR)« less

Plate Tectonics and Taiwan Orogeny based on TAIGER Experiments

NASA Astrophysics Data System (ADS)

Wu, F. T.; Kuochen, H.; McIntosh, K. D.

2014-12-01

Plate tectonics framework is usually complex in a collision zone, where continental lithosphere is involved. In the young Taiwan orogeny, with geologic understanding and large new geodetic and subsurface datasets now available an environment has been created for testing tectonic hypotheses regarding collision and orogeny. Against the background of the commonly accepted view of Taiwan as a southward propagating, self-similar 2-D orogen, a fully 3-D structure is envisaged. Along the whole length of the island the convergence of the Eurasian plate (EUP) the Philippine Sea plate (PSP) takes shape with different plate configurations. In northern Taiwan the convergence occurs with simultaneous collision of the oceanic PSP with continental EUP and the northward subduction of the PSP; in the south, EUP, in the guise of the South China Sea rifted Eurasian continent, subducts toward the east; in central Taiwan collision of oceanic PSP with continental EUP dominates. When relocated seismicity and focal mechanisms are superposed on subsurface P and Vp/Vs velocity images the configurations and the kinematics of the PSP and EUP collision and subduction become clear. While in northern Taiwan the subduction/collision explains well the high peaks and their dwindling (accompanied by crustal thinning) toward the north. In the south, mountains rise above the east-dipping EUP subduction zone as the Eurasian continental shelf veers toward the southwest, divergent from the trend of the Luzon Arc - calling into question the frequently cited arc-continent collision model of Taiwan orogeny. High velocity anomaly and Benioff seismicity coexist in the south. Going north toward Central Taiwan the high velocity anomaly persists for another 150 km or so, but it becomes seismically quiescent. Above the quiescent section the PSP and EUP collide to build the main part of the Central Range and its parallel neighbor the eastern Coastal Range. Key implications regarding orogeny include: 1) Significant petrological changes may accompany the crustal thickening, e.g., eclogitization, and delamination, 2) Rather than the detachment the exhumation of the metamorphic core of the Central Range is the main engine of the orogeny, and 3) The lithosphere has a complex rheological structure, indicated, in part, by the spatial distribution of seismicity.

A new model for early Earth: heat-pipe cooling

NASA Astrophysics Data System (ADS)

Webb, A. G.; Moore, W. B.

2013-12-01

In the study of heat transport and lithospheric dynamics of early Earth, current models depend upon plate tectonic and vertical tectonic concepts. Plate tectonic models adequately account for regions with diverse lithologies juxtaposed along ancient shear zones, as seen at the famous Eoarchean Isua supracrustal belt of West Greenland. Vertical tectonic models to date have involved volcanism, sub- and intra-lithospheric diapirism, and sagduction, and can explain the geology of the best-preserved low-grade ancient terranes, such as the Paleoarchean Barberton and Pilbara greenstone belts. However, these models do not offer a globally-complete framework consistent with the geologic record. Plate tectonics models suggest that paired metamorphic belts and passive margins are among the most likely features to be preserved, but the early rock record shows no evidence of these terranes. Existing vertical tectonics models account for the >300 million years of semi-continuous volcanism and diapirism at Barberton and Pilbara, but when they explain the shearing record at Isua, they typically invoke some horizontal motion that cannot be differentiated from plate motion and is not a salient feature of the lengthy Barberton and Pilbara records. Despite the strengths of these models, substantial uncertainty remains about how early Earth evolved from magma ocean to plate tectonics. We have developed a new model, based on numerical simulations and analysis of the geologic record, that provides a coherent, global geodynamic framework for Earth's evolution from magma ocean to subduction tectonics. We hypothesize that heat-pipe cooling offers a viable mechanism for the lithospheric dynamics of early Earth. Our numerical simulations of heat-pipe cooling on early Earth indicate that a cold, thick, single-plate lithosphere developed as a result of frequent volcanic eruptions that advected surface materials downward. The constant resurfacing and downward advection caused compression as the surface rocks were forced radially inward, resulting in uplift, exhumation, and shortening. Declining heat sources over time led to an abrupt, dynamically spontaneous transition to plate tectonics. The model predicts a geological record with rapid, semi-continuous volcanic resurfacing; contractional deformation; a low geothermal gradient across the bulk of the lithosphere; and a rapid decrease in heat-pipe volcanism after the initiation of plate tectonics. Review of data from ancient cratons and the detrital zircon record is consistent with these predictions. In this presentation, we review these findings with a focus on comparison of the model predictions with the geologic record. This comparison suggests that Earth cooled via heat pipes until a ~3.2 Ga subduction initiation episode. The Isua record reflects long-lived contractional deformation, and the Barberton and Pilbara records preserve heat-pipe lithospheric development in regions without significant contraction. In summary, the heat-pipe model provides a view of early Earth that is more globally applicable than existing plate and vertical tectonic models.

Comparative analysis of geodynamic activity of the Caucasian and Eastern Mediterranean segments of the Alpine-Himalayan convergence zone

NASA Astrophysics Data System (ADS)

Chelidze, Tamaz; Eppelbaum, Lev

2013-04-01

The Alpine-Himalayan convergence zone (AHCZ) underwent recent transverse shortening under the effect of collisional compression. The process was accompanied by rotation of separate microplates. The Caucasian and Eastern Mediterranean regions are segments of the of the AHCZ and are characterized by intensive endogenous and exogenous geodynamic processes, which manifest themselves in occurrence of powerful (with magnitude of 8-9) earthquakes accompanied by development of secondary catastrophic processes. Large landslides, rock falls, avalanches, mud flows, etc. cause human deaths and great material losses. The development of the aforesaid endogenous processes is set forth by peculiarities of the deep structure of the region and an impact of deep geological processes. The Caucasus is divided into several main tectonic terranes: platform (sub-platform, quasi-platform) and fold-thrust units. Existing data enable to perform a division of the Caucasian region into two large-scale geological provinces: southern Tethyan and northern Tethyan located to the south of and to the north of the Lesser Caucasian ophiolite suture, respectively. The recent investigations show that the assessments of the seismic hazard in these regions are not quite correct - for example in the West Caucasus the seismic hazard can be significantly underestimated, which affects the corresponding risk assessments. Integrated analysis of gravity, magnetic, seismic and thermal data enables to refine the assessment of the seismic hazard of the region, taking into account real rates of the geodynamic movements. Important role play the last rheological constructions. According to Reilinger et al. (2006) tectonic scheme, the West flanking of the Arabian Plate manifests strike-slip motion, when the East Caucasian block is converging and shortening. The Eastern Mediterranean is a tectonically complex region located in the midst of the progressive Afro-Eurasian collision. The recent increasing geotectonic activity in this region highlights the need for combined analysis of seismo-neotectonic signatures. For this purpose, this article presents the key features of the tectonic zonation of the Eastern Mediterranean. Map of derivatives of the gravity field retracked from the Geosat satellite and novel map of the Moho discontinuity illustrate the most important tectonic features of the region. The Post-Jurassic map of the deformation of surface leveling reflects the modern tectonic stage of Eastern Mediterranean evolution. The developed tectono-geophysical zonation map integrates the potential geophysical field analysis and seismic section utilization, as well as tectonic-structural, paleogeographical and facial analyses. Tectonically the map agrees with the earlier model of continental accretion (Ben-Avraham and Ginzburg, 1990). Overlaying the seismicity map of the Eastern Mediterranean tectonic region (for the period between 1900 and 2012) on the tectonic zonation chart reveals the key features of the seismo-neotectonic pattern of the Eastern Mediterranean. The results have important implications for tectonic-seismological analysis in this region (Eppelbaum and Katz, 2012). A difference in the geotectonic patterns makes interesting comparison of geodynamic activity and seismic hazard of the Caucasian and Eastern Mediterranean segments of the AHCZ.

Extraction of Protein-Protein Interaction from Scientific Articles by Predicting Dominant Keywords

PubMed Central

Koyabu, Shun; Phan, Thi Thanh Thuy; Ohkawa, Takenao

2015-01-01

For the automatic extraction of protein-protein interaction information from scientific articles, a machine learning approach is useful. The classifier is generated from training data represented using several features to decide whether a protein pair in each sentence has an interaction. Such a specific keyword that is directly related to interaction as “bind” or “interact” plays an important role for training classifiers. We call it a dominant keyword that affects the capability of the classifier. Although it is important to identify the dominant keywords, whether a keyword is dominant depends on the context in which it occurs. Therefore, we propose a method for predicting whether a keyword is dominant for each instance. In this method, a keyword that derives imbalanced classification results is tentatively assumed to be a dominant keyword initially. Then the classifiers are separately trained from the instance with and without the assumed dominant keywords. The validity of the assumed dominant keyword is evaluated based on the classification results of the generated classifiers. The assumption is updated by the evaluation result. Repeating this process increases the prediction accuracy of the dominant keyword. Our experimental results using five corpora show the effectiveness of our proposed method with dominant keyword prediction. PMID:26783534

Global evaluation of erosion rates in relation to tectonics

NASA Astrophysics Data System (ADS)

Hecht, Hagar; Oguchi, Takashi

2017-12-01

Understanding the mechanisms and controlling factors of erosion rates is essential in order to sufficiently comprehend bigger processes such as landscape evolution. For decades, scientists have been researching erosion rates where one of the main objectives was to find the controlling factors. A variety of parameters have been suggested ranging from climate-related, basin morphometry and the tectonic setting of an area. This study focuses on the latter. We use previously published erosion rate data obtained mainly using 10Be and sediment yield and sediment yield data published by the United States Geological Survey. We correlate these data to tectonic-related factors, i.e., distance to tectonic plate boundary, peak ground acceleration ( PGA), and fault distribution. We also examine the relationship between erosion rate and mean basin slope and find significant correlations of erosion rates with distance to tectonic plate boundary, PGA, and slope. The data are binned into high, medium, and low values of each of these parameters and grouped in all combinations. We find that groups with a combination of high PGA (> 0.2.86 g) and long distance (> 1118.69 km) or low PGA (< 0.68 g) and short distance (< 94.34 km) are almost inexistent suggesting a strong coupling between PGA and distance to tectonic plate boundary. Groups with low erosion rates include long distance and/or low PGA, and groups with high erosion rates include neither of these. These observations indicate that tectonics plays a major role in determining erosion rates, which is partly ascribable to steeper slopes produced by active crustal movements. However, our results show no apparent correlation of slope with erosion rates, pointing to problems with using mean basin-wide slope as a slope indicator because it does not represent the complex slope distribution within a basin.

A record of Appalachian denudation in postrift Mesozoic and Cenozoic sedimentary deposits of the U.S. Middle Atlantic continental margin

USGS Publications Warehouse

Poag, C.W.; Sevon, W.D.

1989-01-01

The complex interplay between source-terrain uplift, basin subsidence, paleoclimatic shifts, and sea-level change, left an extensive sedimentary record in the contiguous offshore basins of the U.S. middle Atlantic margin (Salisbury Embayment, Baltimore Canyon Trough, and Hatteras Basin). Isopach maps of 23 postrift (Lower Jurassic to Quaternary) a allostratigraphic units, coupled with a revised stratigraphic framework, reveal that tectonism, by regulating sediment supply (accumulation rate), dominated the interplay of forcing mechanisms. Tectonic pulses are evidenced by abruptly accelerated sediment accumulation, marked latitudinal shifts in the location of depocenters, and regional changes in lithofacies. Relatively rapid tectonic subsidence during the Early and Middle Jurassic history of the basins may have enhanced sediment accumulation rates. Beginning in the Late Jurassic, however, subsidence rates decreased significantly, though occasional short pulses of subsidence may have effected relative sea-level rises. Sea-level change heavily influenced the distribution and redistribution of sediments one they reached the basins, and paleoclimate regulated the relative abundance of carbonates and evaporites in the basins. We conclude that source terrains of the central Appalachian Highlands were tectonically uplifted, intensely weathered, and rapidly eroded three times since the Late Triassic: (1) Early to Middle Jurassic (Aalenian to Callovian); (2) mid-Early Cretaceous (Barremian); and (3) Late Cenozoic (Middle Miocene). Intervals of tectonic quiescence following these three tectonic pulses provided conditions suitable for the formation of regional erosion surfaces, geomorphic features commonly reported to characterize the central Appalachian Highlands. This series of three, irregularly spaced, tectonic/quiescent cycles does not, however, match the traditional four-cycle concept of post-Triassic Appalachian "peneplanation". ?? 1989.

Mid-Pleistocene climate transition drives net mass loss from rapidly uplifting St. Elias Mountains, Alaska.

PubMed

Gulick, Sean P S; Jaeger, John M; Mix, Alan C; Asahi, Hirofumi; Bahlburg, Heinrich; Belanger, Christina L; Berbel, Glaucia B B; Childress, Laurel; Cowan, Ellen; Drab, Laureen; Forwick, Matthias; Fukumura, Akemi; Ge, Shulan; Gupta, Shyam; Kioka, Arata; Konno, Susumu; LeVay, Leah J; März, Christian; Matsuzaki, Kenji M; McClymont, Erin L; Moy, Chris; Müller, Juliane; Nakamura, Atsunori; Ojima, Takanori; Ribeiro, Fabiana R; Ridgway, Kenneth D; Romero, Oscar E; Slagle, Angela L; Stoner, Joseph S; St-Onge, Guillaume; Suto, Itsuki; Walczak, Maureen D; Worthington, Lindsay L; Bailey, Ian; Enkelmann, Eva; Reece, Robert; Swartz, John M

2015-12-08

Erosion, sediment production, and routing on a tectonically active continental margin reflect both tectonic and climatic processes; partitioning the relative importance of these processes remains controversial. Gulf of Alaska contains a preserved sedimentary record of the Yakutat Terrane collision with North America. Because tectonic convergence in the coastal St. Elias orogen has been roughly constant for 6 My, variations in its eroded sediments preserved in the offshore Surveyor Fan constrain a budget of tectonic material influx, erosion, and sediment output. Seismically imaged sediment volumes calibrated with chronologies derived from Integrated Ocean Drilling Program boreholes show that erosion accelerated in response to Northern Hemisphere glacial intensification (∼ 2.7 Ma) and that the 900-km-long Surveyor Channel inception appears to correlate with this event. However, tectonic influx exceeded integrated sediment efflux over the interval 2.8-1.2 Ma. Volumetric erosion accelerated following the onset of quasi-periodic (∼ 100-ky) glacial cycles in the mid-Pleistocene climate transition (1.2-0.7 Ma). Since then, erosion and transport of material out of the orogen has outpaced tectonic influx by 50-80%. Such a rapid net mass loss explains apparent increases in exhumation rates inferred onshore from exposure dates and mapped out-of-sequence fault patterns. The 1.2-My mass budget imbalance must relax back toward equilibrium in balance with tectonic influx over the timescale of orogenic wedge response (millions of years). The St. Elias Range provides a key example of how active orogenic systems respond to transient mass fluxes, and of the possible influence of climate-driven erosive processes that diverge from equilibrium on the million-year scale.

Continental crust formation on early Earth controlled by intrusive magmatism

NASA Astrophysics Data System (ADS)

Rozel, A. B.; Golabek, G. J.; Jain, C.; Tackley, P. J.; Gerya, T.

2017-05-01

The global geodynamic regime of early Earth, which operated before the onset of plate tectonics, remains contentious. As geological and geochemical data suggest hotter Archean mantle temperature and more intense juvenile magmatism than in the present-day Earth, two crust-mantle interaction modes differing in melt eruption efficiency have been proposed: the Io-like heat-pipe tectonics regime dominated by volcanism and the “Plutonic squishy lid” tectonics regime governed by intrusive magmatism, which is thought to apply to the dynamics of Venus. Both tectonics regimes are capable of producing primordial tonalite-trondhjemite-granodiorite (TTG) continental crust but lithospheric geotherms and crust production rates as well as proportions of various TTG compositions differ greatly, which implies that the heat-pipe and Plutonic squishy lid hypotheses can be tested using natural data. Here we investigate the creation of primordial TTG-like continental crust using self-consistent numerical models of global thermochemical convection associated with magmatic processes. We show that the volcanism-dominated heat-pipe tectonics model results in cold crustal geotherms and is not able to produce Earth-like primordial continental crust. In contrast, the Plutonic squishy lid tectonics regime dominated by intrusive magmatism results in hotter crustal geotherms and is capable of reproducing the observed proportions of various TTG rocks. Using a systematic parameter study, we show that the typical modern eruption efficiency of less than 40 per cent leads to the production of the expected amounts of the three main primordial crustal compositions previously reported from field data (low-, medium- and high-pressure TTG). Our study thus suggests that the pre-plate-tectonics Archean Earth operated globally in the Plutonic squishy lid regime rather than in an Io-like heat-pipe regime.

Spatial variation of present-day stress field and tectonic regime in Tunisia and surroundings from formal inversion of focal mechanisms: Geodynamic implications for central Mediterranean

NASA Astrophysics Data System (ADS)

Soumaya, Abdelkader; Ben Ayed, Noureddine; Delvaux, Damien; Ghanmi, Mohamed

2015-06-01

We compiled 123 focal mechanisms from various sources for Tunisia and adjacent regions up to Sicily, to image the current stress field in the Maghrebides chain (from Tunisia to Sicily) and its foreland. Stress inversion of all the available data provides a first-order stress field with a N150°E horizontal compression (SHmax) and a transpressional tectonic regime, but the obtained stress tensor poorly fit to the data set. We separated them into regional subsets (boxes) in function of their geographical proximity, kinematic regime, homogeneity of kinematic orientations, and tectonic setting. Their respective inversion evidences second- and third-order spatial variations in tectonic regime and horizontal stress directions. The stress field gradually changes from compression in the Maghrebides thrust belt to transpression and strike slip in the Atlassic and Pelagian foreland, respectively, where preexisting NW-SE to E-W deep faults system are reactivated. This spatial variation of the sismotectonic stress field and tectonic regime is consistent with the neotectonic stress field determined by others from fault slip data. The major Slab Transfer Edge Propagator faults (i.e., North-South Axis-Hammamet relay and Malte Escarpment), which laterally delimit the subducting slabs, play an active role in second- and third-order lateral variations of the tectonic regime and stress field orientations over the Tunisian/Sicilian domain. The past and current tectonic deformations and kinematics of the central Mediterranean are subordinately guided by the plate convergence (i.e., Africa-Eurasia), controlled or influenced by lateral slab migration/segmentation and by deep dynamics such as lithosphere-mantle interaction.

Pennsylvanian history of the Chautauqua Arch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennison, A.P.

1993-03-01

Westward extension of the Ozark Uplift known as the Chautauqua Arch is concealed by a Pennsylvanian cover. This cover provides an insight into its later tectonic history subsequent to its major Late Devonian uplift and truncation. Part of this arch was episodically uplifted during Pennsylvanian time in an area extending west from southwestern Missouri along the Kansas-Oklahoma border to western Montgomery County. Recent stratigraphic mapping in that county indicates moderate Late Desmoinesian to Missourian tectonism. Some strata present on both flanks of the arch are either comparatively thin or missing owing to unconformity truncation or non-deposition. Stratal loss involves themore » Lenapah Limestone, the Hepler and Lost Branch formations, the Cherryvale Shale and the Hertha, Drum, Dewey, Stanton and Wyandotte Limestones. Earlier movements also account for the truncation of Morrowan, Atokan and possibly some Early Desmoinesian beds over the arch. Between tectonic episodes along the arch there were periods of relative tectonic quiescence accompanied by shelf-edge carbonate banks, condensed sequences and siliciclastic sedimentation. West of Montgomery County in Chautauqua County, the widespread Late Pennsylvanian Virgilian outcrops show practically no tectonism. Therefore, the name Chautauqua Arch seems inappropriate for this Pennsylvanian arch, and the name Tri-State Arch is proposed. This arch is bounded on the north by the Cherokee Basin and on the south by the northern rise of the Arkoma Basin. Although this arch is commonly omitted on many tectonic maps, it is a stronger gravity feature than the Bourbon Arch about 50 miles northward. Both tectonic and sedimentary structures have produced much oil and gas entrapment along this arch. For example, an east-west fault south of Independence, aligned with buried Proterozoic hills, has been specially productive.« less

Trans-Alaska Crustal Transect and continental evolution involving subduction underplating and synchronous foreland thrusting

USGS Publications Warehouse

Fuis, G.S.; Moore, Thomas E.; Plafker, G.; Brocher, T.M.; Fisher, M.A.; Mooney, W.D.; Nokleberg, W.J.; Page, R.A.; Beaudoin, B.C.; Christensen, N.I.; Levander, A.R.; Lutter, W.J.; Saltus, R.W.; Ruppert, N.A.

2008-01-01

We investigate the crustal structure and tectonic evolution of the North American continent in Alaska, where the continent has grown through magmatism, accretion, and tectonic underplating. In the 1980s and early 1990s, we conducted a geological and geophysical investigation, known as the Trans-Alaska Crustal Transect (TACT), along a 1350-km-long corridor from the Aleutian Trench to the Arctic coast. The most distinctive crustal structures and the deepest Moho along the transect are located near the Pacific and Arctic margins. Near the Pacific margin, we infer a stack of tectonically underplated oceanic layers interpreted as remnants of the extinct Kula (or Resurrection) plate. Continental Moho just north of this underplated stack is more than 55 km deep. Near the Arctic margin, the Brooks Range is underlain by large-scale duplex structures that overlie a tectonic wedge of North Slope crust and mantle. There, the Moho has been depressed to nearly 50 km depth. In contrast, the Moho of central Alaska is on average 32 km deep. In the Paleogene, tectonic underplating of Kula (or Resurrection) plate fragments overlapped in time with duplexing in the Brooks Range. Possible tectonic models linking these two regions include flat-slab subduction and an orogenic-float model. In the Neogene, the tectonics of the accreting Yakutat terrane have differed across a newly interpreted tear in the subducting Pacific oceanic lithosphere. East of the tear, Pacific oceanic lithosphere subducts steeply and alone beneath the Wrangell volcanoes, because the overlying Yakutat terrane has been left behind as underplated rocks beneath the rising St. Elias Range, in the coastal region. West of the tear, the Yakutat terrane and Pacific oceanic lithosphere subduct together at a gentle angle, and this thickened package inhibits volcanism. ?? 2008 The Geological Society of America.

Continental crust formation on early Earth controlled by intrusive magmatism.

PubMed

Rozel, A B; Golabek, G J; Jain, C; Tackley, P J; Gerya, T

2017-05-18

The global geodynamic regime of early Earth, which operated before the onset of plate tectonics, remains contentious. As geological and geochemical data suggest hotter Archean mantle temperature and more intense juvenile magmatism than in the present-day Earth, two crust-mantle interaction modes differing in melt eruption efficiency have been proposed: the Io-like heat-pipe tectonics regime dominated by volcanism and the "Plutonic squishy lid" tectonics regime governed by intrusive magmatism, which is thought to apply to the dynamics of Venus. Both tectonics regimes are capable of producing primordial tonalite-trondhjemite-granodiorite (TTG) continental crust but lithospheric geotherms and crust production rates as well as proportions of various TTG compositions differ greatly, which implies that the heat-pipe and Plutonic squishy lid hypotheses can be tested using natural data. Here we investigate the creation of primordial TTG-like continental crust using self-consistent numerical models of global thermochemical convection associated with magmatic processes. We show that the volcanism-dominated heat-pipe tectonics model results in cold crustal geotherms and is not able to produce Earth-like primordial continental crust. In contrast, the Plutonic squishy lid tectonics regime dominated by intrusive magmatism results in hotter crustal geotherms and is capable of reproducing the observed proportions of various TTG rocks. Using a systematic parameter study, we show that the typical modern eruption efficiency of less than 40 per cent leads to the production of the expected amounts of the three main primordial crustal compositions previously reported from field data (low-, medium- and high-pressure TTG). Our study thus suggests that the pre-plate-tectonics Archean Earth operated globally in the Plutonic squishy lid regime rather than in an Io-like heat-pipe regime.

Plate tectonics, damage and inheritance.

PubMed

Bercovici, David; Ricard, Yanick

2014-04-24

The initiation of plate tectonics on Earth is a critical event in our planet's history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately 3 billion years ago) suggests that plates and plate boundaries became widespread over a period of 1 billion years. The reason for this time lag is unknown but fundamental to understanding the origin of plate tectonics. Here we suggest that when sufficient lithospheric damage (which promotes shear localization and long-lived weak zones) combines with transient mantle flow and migrating proto-subduction, it leads to the accumulation of weak plate boundaries and eventually to fully formed tectonic plates driven by subduction alone. We simulate this process using a grain evolution and damage mechanism with a composite rheology (which is compatible with field and laboratory observations of polycrystalline rocks), coupled to an idealized model of pressure-driven lithospheric flow in which a low-pressure zone is equivalent to the suction of convective downwellings. In the simplest case, for Earth-like conditions, a few successive rotations of the driving pressure field yield relic damaged weak zones that are inherited by the lithospheric flow to form a nearly perfect plate, with passive spreading and strike-slip margins that persist and localize further, even though flow is driven only by subduction. But for hotter surface conditions, such as those on Venus, accumulation and inheritance of damage is negligible; hence only subduction zones survive and plate tectonics does not spread, which corresponds to observations. After plates have developed, continued changes in driving forces, combined with inherited damage and weak zones, promote increased tectonic complexity, such as oblique subduction, strike-slip boundaries that are subparallel to plate motion, and spalling of minor plates.

Off-axis volcano-tectonic activity during continental rifting: Insights from the transversal Goba-Bonga lineament, Main Ethiopian Rift (East Africa)

NASA Astrophysics Data System (ADS)

Corti, Giacomo; Sani, Federico; Agostini, Samuele; Philippon, Melody; Sokoutis, Dimitrios; Willingshofer, Ernst

2018-03-01

The Main Ethiopian Rift, East Africa, is characterized by the presence of major, enigmatic structures which strike approximately orthogonal to the trend of the rift valley. These structures are marked by important deformation and magmatic activity in an off-axis position in the plateaus surrounding the rift. In this study, we present new structural data based on a remote and field analysis, complemented with analogue modelling experiments, and new geochemical analysis of volcanic rocks sampled in different portions of one of these transversal structures: the Goba-Bonga volcano-tectonic lineament (GBVL). This integrated analysis shows that the GBVL is associated with roughly E-W-trending prominent volcano-tectonic activity affecting the western plateau. Within the rift floor, the approximately E-W alignment of Awasa and Corbetti calderas likely represent expressions of the GBVL. Conversely, no tectonic or volcanic features of similar (E-W) orientation have been recognized on the eastern plateau. Analogue modelling suggests that the volcano-tectonic features of the GBVL have probably been controlled by the presence of a roughly E-W striking pre-existing discontinuity beneath the western plateau, which did not extend beneath the eastern plateau. Geochemical analysis supports this interpretation and indicates that, although magmas have the same sub-lithospheric mantle source, limited differences in magma evolution displayed by products found along the GBVL may be ascribed to the different tectonic framework to the west, to the east, and in the axial zone of the rift. These results support the importance of the heterogeneous nature of the lithosphere and the spatial variations of its structure in controlling the architecture of continental rifts and the distribution of the related volcano-tectonic activity.

Geological setting of the southern termination of Western Alps

NASA Astrophysics Data System (ADS)

d'Atri, Anna; Piana, Fabrizio; Barale, Luca; Bertok, Carlo; Martire, Luca

2016-09-01

A revision of the stratigraphic and tectonic setting of the southern termination of the Western Alps, at the junction of the Maritime Alps with the westernmost Ligurian Alps, is proposed. In response to the Alpine kinematic evolution, a number of tectonic units formed on the deformed palaeo-European continental margin and were arranged in a NW-SE striking anastomosed pattern along the north-eastern boundary of the Argentera Massif. Because these tectonic units often cut across the palaeogeographic subdivision of the Alpine literature and show only partial affinity with their distinctive stratigraphic features, new attributions are proposed. The Subbriançonnais domain is here intended as a "deformation zone", and its tectonic units have been attributed to Dauphinois and Provençal domains; furthermore, the Eocene Alpine Foreland Basin succession has been interpreted, based on the affinity of its lithologic characters and age, as a single feature resting above all the successions of the different Mesozoic domains. The Cretaceous tectono-sedimentary evolution of the studied domains was characterized by intense tectonic controls on sedimentation inducing lateral variations of stratigraphic features and major hydrothermal phenomena. Since the early Oligocene, transpressional tectonics induced a NE-SW shortening, together with significant left-lateral movements followed by (late Oligocene-middle Miocene) right-lateral movements along E-W to SE-NW striking shear zones. This induced the juxtaposition and/or stacking of Briançonnais, Dauphinois and Ligurian tectonic units characterized by different metamorphic histories, from anchizonal to lower greenschist facies. This evolution resulted in the arrangement of the tectonostratigraphic units in a wide "transfer zone" accommodating the Oligocene WNW-ward movement of portions of the palaeo-European margin placed at the south-western termination of Western Alps and the Miocene dextral shearing along SE striking faults that bound the Argentera Massif on its NE side.

Mid-Pleistocene climate transition drives net mass loss from rapidly uplifting St. Elias Mountains, Alaska

PubMed Central

Jaeger, John M.; Mix, Alan C.; Asahi, Hirofumi; Bahlburg, Heinrich; Belanger, Christina L.; Berbel, Glaucia B. B.; Childress, Laurel; Cowan, Ellen; Drab, Laureen; Forwick, Matthias; Fukumura, Akemi; Ge, Shulan; Gupta, Shyam; Konno, Susumu; LeVay, Leah J.; März, Christian; McClymont, Erin L.; Moy, Chris; Müller, Juliane; Nakamura, Atsunori; Ojima, Takanori; Ribeiro, Fabiana R.; Ridgway, Kenneth D.; Romero, Oscar E.; Slagle, Angela L.; Stoner, Joseph S.; St-Onge, Guillaume; Suto, Itsuki; Walczak, Maureen D.; Worthington, Lindsay L.; Bailey, Ian; Enkelmann, Eva; Reece, Robert; Swartz, John M.

2015-01-01

Erosion, sediment production, and routing on a tectonically active continental margin reflect both tectonic and climatic processes; partitioning the relative importance of these processes remains controversial. Gulf of Alaska contains a preserved sedimentary record of the Yakutat Terrane collision with North America. Because tectonic convergence in the coastal St. Elias orogen has been roughly constant for 6 My, variations in its eroded sediments preserved in the offshore Surveyor Fan constrain a budget of tectonic material influx, erosion, and sediment output. Seismically imaged sediment volumes calibrated with chronologies derived from Integrated Ocean Drilling Program boreholes show that erosion accelerated in response to Northern Hemisphere glacial intensification (∼2.7 Ma) and that the 900-km-long Surveyor Channel inception appears to correlate with this event. However, tectonic influx exceeded integrated sediment efflux over the interval 2.8–1.2 Ma. Volumetric erosion accelerated following the onset of quasi-periodic (∼100-ky) glacial cycles in the mid-Pleistocene climate transition (1.2–0.7 Ma). Since then, erosion and transport of material out of the orogen has outpaced tectonic influx by 50–80%. Such a rapid net mass loss explains apparent increases in exhumation rates inferred onshore from exposure dates and mapped out-of-sequence fault patterns. The 1.2-My mass budget imbalance must relax back toward equilibrium in balance with tectonic influx over the timescale of orogenic wedge response (millions of years). The St. Elias Range provides a key example of how active orogenic systems respond to transient mass fluxes, and of the possible influence of climate-driven erosive processes that diverge from equilibrium on the million-year scale. PMID:26598689

2D and 3D Modeling of the Stratigraphic Sequences at the Adriatic and Rhone Continental Margins

DTIC Science & Technology

2005-09-30

Grenerczy, D. Medak, S. Stein, and J. C. Weber (Eds.). The Adria Microplate : GPS Geodesy, Tectonics , and Hazards. Kluwer Academic Publisher, pp. 93-116... tectonics , and their influences on sequence architecture. John Swenson, with assistance from Chris Paola, Juan Fedele, myself and others have jointly...exploration of the margin’s response to variations in sea level, sediment supply, tectonic subsidence, and wave climate over longer timescales. I am

Southern California landslides-an overview

USGS Publications Warehouse

,

2005-01-01

Southern California lies astride a major tectonic plate boundary defined by the San Andreas Fault and numerous related faults that are spread across a broad region. This dynamic tectonic environment has created a spectacular landscape of rugged mountains and steep-walled valleys that compose much of the region’s scenic beauty. Unfortunately, this extraordinary landscape also presents serious geologic hazards. Just as tectonic forces are steadily pushing the landscape upward, gravity is relentlessly tugging it downward. When gravity prevails, landslides can occur.

Measurement of tectonic surface uplift rate in a young collisional mountain belt

USGS Publications Warehouse

Abbott, L.D.; Silver, E.A.; Anderson, R. Scott; Smith, R.; Ingle, J.C.; Kling, S.A.; Haig, D.; Small, E.; Galewsky, J.; Sliter, W.

1997-01-01

Measurement of the rate of tectonically driven surface uplift is crucial to a complete understanding of mountain building dynamics. The lack of a suitable rock record typically prevents determination of this quantity, but the unusual geology of Papua New Guinea's Finisterre mountains makes measurement of this rate possible. The tectonic surface uplift rate at the Finisterre range is 0.8-2.1 mm yr-1, approximately that expected to arise from crustal thickening.

A Review of Tectonic Models and Analytical Data from Almora-Dadeldhura Klippe, Northwest India and Far Western Nepal.

NASA Astrophysics Data System (ADS)

Bosu, S.; Robinson, D.; Saha, A.

2017-12-01

Tectonic models developed from the Himalayan thrust belt constitute three models- critical taper, channel flow and wedge extrusion. Their differences are manifested in predicted minimum shortening, deformation propagation style and tectonic architecture across the thrust belt. Recent studies from isolated synformal klippen composed of Greater and Tethyan Himalayan rock within the Himalayan thrust belt disagree over the tectonic history, especially in the Almora-Dadeldhura klippe, which is the largest klippe in the thrust belt. These recent studies are limited to one transect each, and two or fewer types of analytical data to justify their models. Due to the limited spatial coverage, these studies often reflect a narrow perspective in their tectonic models; thus, combining the data from these studies provides a holistic view of the regional tectonic history. This study compiled the available data across the 350 km wide Almora-Dadeldhura klippe, using petrology, stratigraphy, metamorphic history, microstructure, U-Pb ages of intrusive granite, monazite and muscovite ages of the shear zones, and exhumation ages from apatite fission track, along with original field observations, microstructure and microtexture data from 5 different transects in northwest India and far western Nepal. The review of the compiled data suggests that the Himalayan thrust belt in northwest India and far western Nepal is a forward propagating thrust system, and that the analytical data support the critical taper model.

Morphotectonic analysis and GNSS observations for assessment of relative tectonic activity in Alaknanda basin of Garhwal Himalaya, India

NASA Astrophysics Data System (ADS)

Sharma, Gopal; Champati ray, P. K.; Mohanty, S.

2018-01-01

Alaknanda basin in the Garhwal Himalaya, India, is a tectonically active region owing to ongoing crustal deformation, erosion, and depositional processes active in the region. Active tectonics in this region have greatly affected the drainage system and geomorphic expression of topography and provide an ideal natural set up to investigate the influence of tectonic activity resulting from the India-Eurasia collision. We evaluated active tectonics by using high resolution digital elevation model (DEM) based on eight geomorphic indices (stream length gradient index, valley floor width-to-height ratio, hypsometric integral, drainage basin asymmetry, transverse topography symmetry factor, mountain front sinousity index, bifurcation ratio, and basin shape index) and seismicity in eight subbasins of Alaknanda basin. The integrated product, relative tectonic activity index (TAI) map, was classified into three classes such as: 'highly active' with values ranging up to 2.0; 'moderately active' with values ranging from 2.0 to 2.25; and 'less active' with values > 2.25. Further, the results were compared with relatively high crustal movement rate of 41.10 mm/y computed through high precession Global Navigation Satellite System (GNSS) based continuous operating reference station (CORS) data. Thus, we concluded that this new quantitative approach can be used for better characterization and assessment of active seismotectonic regions of the Himalaya and elsewhere.

Overview of the Education and Public Outreach (EPO) program of the Caltech Tectonics Observatory

NASA Astrophysics Data System (ADS)

Kovalenko, L.; Jain, K.; Maloney, J.

2009-12-01

The Caltech Tectonics Observatory (TO) is an interdisciplinary center, focused on geological processes occurring at the boundaries of Earth's tectonic plates (http://www.tectonics.caltech.edu). Over the past year, the TO has made a major effort to develop an Education and Public Outreach (EPO) program. Our goals are to (1) stimulate the interest of students and the general public in Earth Sciences, particularly in the study of tectonic processes, (2) inform and educate the general public about science in the context of TO discoveries and advancements, and (3) provide opportunities for graduate students, postdocs, and faculty to do outreach in the local K-12 schools. We have hosted local high school students and teachers to provide them with research experience (as part of Caltech’s “Summer Research Connection”); participated in teacher training workshops (organized by the local school district); hosted tours for local elementary school students; and brought hands-on activities into local elementary and middle school classrooms, science clubs, and science nights. We have also led local school students and teachers on geology field trips through nearby parks. In addition, we have developed education modules for undergraduate classes (as part of MARGINS program), and have written educational web articles on TO research (http://www.tectonics.caltech.edu/outreach). The presentation will give an overview of these activities and their impact on our educational program.

Tertiary fission-track ages from the Bagua syncline (northern Peru): Stratigraphic and tectonic implications

NASA Astrophysics Data System (ADS)

Naeser, C. W.; Crochet, J.-Y.; Jaillard, E.; Laubacher, G.; Mourier, T.; Sigé, B.

The results of five zircon fission-track ages of volcanic tuffs intercalated within the continental deposits of the Bagua syncline (northern Peru) are reported. These 2500-meter-thick deposits overlie mid-Campanian to lower Maastrichtian fine-grained red beds (Fundo El Triunfo Formation). The disconformable fluvial conglomerates of the Rentema Formation are associated with a 54 Ma tuff (upper Paleocene-lower Eocene?) and would reflect the Inca-1 tectonic phase. The Sambimera Formation (Eocene to mid-Miocene) is a coarsening-upward sequence (from lacustrine to fluvial) that contains three volcanic tuffs of 31, 29, and 12 Ma, respectively. A probable stratigraphic gap, upper Eocene-lower Oligocene, would be related to the late Eocene Inca-2 phase. Neither deformation nor sedimentary discontinuity has been recognized so far. However, the lacustrine to fluvial transition could relate to the late Oligocene Aymara tectonic phase. The unconformable fanglomerates and fluvial deposits of the San Antonio Formation contain in their upper part a 9 Ma tuff (mid-to upper Miocene), and thier base records a major tectonic event (Quechua-2 phase?). The unconformable fanglomerates of the Tambopara Formation date the folding of the Bagua syncline, which could be ascribed to the latest Miocene Quechua-3 tectonics. These formations are correlative with comparable deposits in the sub-Andean basins, suggesting that these eastern areas underwent strong tectonic subsidence of the foreland basin type since mid-Miocene times.

Tertiary fission-track ages from the Bagua syncline (northern Peru): Stratigraphic and tectonic implications

USGS Publications Warehouse

Naeser, C.W.; Crochet, J.-Y.; Jaillard, E.; Laubacher, G.; Mourier, T.; Sige, B.

1991-01-01

The results of five zircon fission-track ages of volcanic tuffs intercalated within the continental deposits of the Bagua syncline (northern Peru) are reported. These 2500-meter-thick deposits overlie mid-Campanian to lower Maastrichtian fine-grained red beds (Fundo El Triunfo Formation). The disconformable fluvial conglomerates of the Rentema Formation are associated with a 54 Ma tuff (upper Paleocene-lower Eocene?) and would reflect the Inca-1 tectonic phase. The Sambimera Formation (Eocene to mid-Miocene) is a coarsening-upward sequence (from lacustrine to fluvial) that contains three volcanic tuffs of 31, 29, and 12 Ma, respectively. A probable stratigraphic gap, upper Eocene-lower Oligocene, would be related to the late Eocene Inca-2 phase. Neither deformation nor sedimentary discontinuity has been recognized so far. However, the lacustrine to fluvial transition could relate to the late Oligocene Aymara tectonic phase. The unconformable fanglomerates and fluvial deposits of the San Antonio Formation contain in their upper part a 9 Ma tuff (mid-to upper Miocene), and thier base records a major tectonic event (Quechua-2 phase?). The unconformable fanglomerates of the Tambopara Formation date the folding of the Bagua syncline, which could be ascribed to the latest Miocene Quechua-3 tectonics. These formations are correlative with comparable deposits in the sub-Andean basins, suggesting that these eastern areas underwent strong tectonic subsidence of the foreland basin type since mid-Miocene times. ?? 1991.

Tectonic Terminology: Some Proposed Changes

ERIC Educational Resources Information Center

Hill, Mason L.

1978-01-01

Plate tectonics concepts require a definition of fault, a new term to compliment epeirogeny, and a clarification of transform fault characteristics. This article makes proposals for these changes. (Author/MA)

Seafloor Tectonic Fabric from Satellite Altimetry

NASA Astrophysics Data System (ADS)

Smith, Walter H. F.

Ocean floor structures with horizontal scales of 10 to a few hundred kilometers and vertical scales of 100 m or more generate sea surface gravity anomalies observable with satellite altimetry. Prior to 1990, altimeter data resolved only tectonic lineaments, some seamounts, and some aspects of mid-ocean ridge structure. New altimeter data available since mid-1995 resolve 10-km--scale structures over nearly all the world's oceans. These data are the basis of new global bathymetric maps and have been interpreted as exhibiting complexities in the sea floor spreading process including ridge jumps, propagating rifts, and variations in magma supply. This chapter reviews the satellite altimetry technique and its resolution of tectonic structures, gives examples of intriguing tectonic phenomena, and shows that structures as small as abyssal hills are partially resolved. A new result obtained here is that the amplitude of the fine-scale (10--80 km) roughness of old ocean floor is spreading-rate dependent in the same that it is at mid-ocean ridges, suggesting that fine-scale tectonic fabric is generated nearly exclusively by ridge-axis processes.

Satellite Detection of the Convection Generated Stresses in Earth

NASA Technical Reports Server (NTRS)

Liu, Han-Shou; Kolenkiewicz, Ronald; Li, Jin-Ling; Chen, Jiz-Hong

2003-01-01

We review research developments on satellite detection of the convection generated stresses in the Earth for seismic hazard assessment and Earth resource survey. Particular emphasis is laid upon recent progress and results of stress calculations from which the origin and evolution of the tectonic features on Earth's surface can be scientifically addressed. An important aspect of the recent research development in tectonic stresses relative to earthquakes is the implications for earthquake forecasting and prediction. We have demonstrated that earthquakes occur on the ring of fire around the Pacific in response to the tectonic stresses induced by mantle convection. We propose a systematic global assessment of the seismic hazard based on variations of tectonic stresses in the Earth as observed by satellites. This space geodynamic approach for assessing the seismic hazard is unique in that it can pinpoint the triggering stresses for large earthquakes without ambiguities of geological structures, fault geometries, and other tectonic properties. Also, it is distinct from the probabilistic seismic hazard assessment models in the literature, which are based only on extrapolations of available earthquake data.

Analysis of tectonic features in US southwest from Skylab photographs

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator); Tubbesing, L.

1975-01-01

The author has identified the following significant results. Skylab photographs were utilized to study faults and tectonic lines in selected areas of the U.S. Southwest. Emphasis was on elements of the Texas Zone in the Mojave Desert and the tectonic intersection in southern Nevada. Transverse faults believed to represent the continuation of the Texas Zone were found to be anomalous in strike. This suggests that the Mojave Desert block was rotated counterclockwise as a unit with the Sierra Nevada. Left-lateral strike-slip faults in Lake Mead area are interpreted as elements of the Wasatch tectonic zone; their anomalous trend indicates that the Lake Mead area has rotated clockwise with the Colorado Plateau. A tectonic model relating major fault zones to fragmentation and rotation of crustal blocks was developed. Detailed correlation of the high resolution S190B metric camera photographs with U-2 photographs and geologic maps demonstrates the feasibility of utilizing S190B photographs for the identification of geomorphic features associated with recent and active faults and for the assessment of seismic hazards.

The contraction/expansion history of Charon with implications for its planetary-scale tectonic belt

NASA Astrophysics Data System (ADS)

Malamud, Uri; Perets, Hagai B.; Schubert, Gerald

2017-06-01

The New Horizons mission to the Kuiper belt has recently revealed intriguing features on the surface of Charon, including a network of chasmata, cutting across or around a series of high topography features, conjoining to form a belt. It is proposed that this tectonic belt is a consequence of contraction/expansion episodes in the moon's evolution associated particularly with compaction, differentiation and geochemical reactions of the interior. The proposed scenario involves no need for solidification of a vast subsurface ocean and/or a warm initial state. This scenario is based on a new, detailed thermo-physical evolution model of Charon that includes multiple processes. According to the model, Charon experiences two contraction/expansion episodes in its history that may provide the proper environment for the formation of the tectonic belt. This outcome remains qualitatively the same, for several different initial conditions and parameter variations. The precise orientation of Charon's tectonic belt, and the cryovolcanic features observed south of the tectonic belt may have involved a planetary-scale impact, that occurred only after the belt had already formed.

DELP Symposium: Tectonics of eastern Asia and western Pacific Continental Margin

NASA Astrophysics Data System (ADS)

Eastern Asia and the western Pacific make up a broad region of active plate tectonic interaction. The area is a natural laboratory for studying the processes involved in the origin and evolution of volcanic island arcs, marginal basins, accretionary prisims, oceanic trenches, accreted terranes, ophiolite emplacement, and intracontinental deformation. Many of our working concepts of plate tectonics and intraplate deformation were developed in this region, even though details of the geology and geophysics there must be considered of a reconnaissance nature.During the past few years researchers have accumulated a vast amount of new and detailed information and have developed a better understanding of the processes that have shaped the tectonic elements in this region. To bring together scientists from many disciplines and to present the wide range of new data and ideas that offer a broader perspective on the interrelations of geological, geochemical, geophysical and geodetic studies, the symposium Tectonics of Eastern Asia and Western Pacific Continental Margin was held December 13-16, 1988, at the Tokyo Institute of Technology in Japan, under the auspicies of DELP (Dynamics and Evolution of the Lithosphere Project).

Infodemiology of alcohol use in Hong Kong mentioned on blogs: infoveillance study.

PubMed

Chan, Kl; Ho, Sy; Lam, Th

2013-09-02

In 2007 and 2008, the beer and wine tax in Hong Kong was halved and then abolished, resulting in an increase of alcohol consumption. The prevalence of the Internet and a high blogging rate by adolescents and adults present a unique opportunity to study drinking patterns by infodemiology. To assess and explain the online use of alcohol-related Chinese keywords and to validate blog searching as an infoveillance method for surveying changes in drinking patterns (eg, alcohol type) in Hong Kong people (represented by bloggers on a Hong Kong-based Chinese blogging site) in 2005-2010. Blog searching was done using a blog search engine, Google Blog Search, in the archives of a Hong Kong-based blog service provider, MySinaBlog from 2005-2010. Three groups of Chinese keywords, each representing a specific alcohol-related concept, were used: (1) "alcohol" (ie, the control concept), (2) "beer or wine", and (3) "spirit". The resulting blog posts were analyzed quantitatively using infodemiological metrics and correlation coefficients, and qualitatively by manual effort. The infodemiological metrics were (1) apparent prevalence, (2) actual prevalence, (3) prevalence rate, and (4) prevalence ratio. Pearson and Spearman correlations were calculated for prevalence rates and ratios with respect to per capita alcohol consumption. Manual analysis focused on (1) blog author characteristics (ie, authorship, sex, and age), and (2) blog content (ie, frequency of keywords, description of a discrete episode of alcohol drinking, drinking amount, and genres). The online use of alcohol-related concepts increased noticeably for "alcohol" in 2008 and "spirit" in 2008-2009 but declined for "beer or wine" over the years. Correlation between infodemiological and epidemiological data was only significant for the "alcohol" prevalence rate. Most blogs were managed by single authors. Their sex distribution was even, and the majority were aged 18 and above. Not all Chinese keywords were found. Many of the blog posts did not describe a discrete episode of alcohol drinking and were classified as personal diary, opinion, or emotional outlets. The rest lacked information on drinking amount, which hindered assessment of binge drinking. The prevalence of alcohol-related Chinese keywords online was attributed to many different factors, including spam, and hence not a specific reflection of local drinking patterns. Correlation between infodemiological data (represented by prevalence rates and ratios of alcohol-related concepts) and epidemiological data (represented by per capita alcohol consumption) was poor. Many blog posts were affective rather than informative in nature. Semantic analysis of blog content was recommended given enough expertise and resources.

Standardization of Keyword Search Mode

ERIC Educational Resources Information Center

Su, Di

2010-01-01

In spite of its popularity, keyword search mode has not been standardized. Though information professionals are quick to adapt to various presentations of keyword search mode, novice end-users may find keyword search confusing. This article compares keyword search mode in some major reference databases and calls for standardization. (Contains 3…

The Interaction Network Ontology-supported modeling and mining of complex interactions represented with multiple keywords in biomedical literature.

PubMed

Özgür, Arzucan; Hur, Junguk; He, Yongqun

2016-01-01

The Interaction Network Ontology (INO) logically represents biological interactions, pathways, and networks. INO has been demonstrated to be valuable in providing a set of structured ontological terms and associated keywords to support literature mining of gene-gene interactions from biomedical literature. However, previous work using INO focused on single keyword matching, while many interactions are represented with two or more interaction keywords used in combination. This paper reports our extension of INO to include combinatory patterns of two or more literature mining keywords co-existing in one sentence to represent specific INO interaction classes. Such keyword combinations and related INO interaction type information could be automatically obtained via SPARQL queries, formatted in Excel format, and used in an INO-supported SciMiner, an in-house literature mining program. We studied the gene interaction sentences from the commonly used benchmark Learning Logic in Language (LLL) dataset and one internally generated vaccine-related dataset to identify and analyze interaction types containing multiple keywords. Patterns obtained from the dependency parse trees of the sentences were used to identify the interaction keywords that are related to each other and collectively represent an interaction type. The INO ontology currently has 575 terms including 202 terms under the interaction branch. The relations between the INO interaction types and associated keywords are represented using the INO annotation relations: 'has literature mining keywords' and 'has keyword dependency pattern'. The keyword dependency patterns were generated via running the Stanford Parser to obtain dependency relation types. Out of the 107 interactions in the LLL dataset represented with two-keyword interaction types, 86 were identified by using the direct dependency relations. The LLL dataset contained 34 gene regulation interaction types, each of which associated with multiple keywords. A hierarchical display of these 34 interaction types and their ancestor terms in INO resulted in the identification of specific gene-gene interaction patterns from the LLL dataset. The phenomenon of having multi-keyword interaction types was also frequently observed in the vaccine dataset. By modeling and representing multiple textual keywords for interaction types, the extended INO enabled the identification of complex biological gene-gene interactions represented with multiple keywords.

Tectonic Plate Movement.

ERIC Educational Resources Information Center

Landalf, Helen

1998-01-01

Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

Digital structural

USGS Publications Warehouse

Dohm, J.M.; Anderson, R.C.; Tanaka, K.L.

1998-01-01

Magmatic and tectonic activity have both contributed significantly to the surface geology of Mars. Digital structural mapping techniques have now been used to classify and date centers of tectonic activity in the western equatorial region. For example, our results show a center of tectonic activity at Valles Marineris, which may be associated with uplift caused by intrusion. Such evidence may help explain, in part, the development of the large troughs and associated outflow channels and chaotic terrain. We also find a local centre of tectonic activity near the source region of Warrego Valles. Here, we suggest that the valley system may have resulted largely from intrusive-related hydrothermal activity. We hope that this work, together with the current Mars Global Surveyor mission, will lead to a better understanding of the geological processes that shaped the Martian surface.

The tectonics of Venus: An overview

NASA Technical Reports Server (NTRS)

Solomon, Sean C.

1992-01-01

While the Pioneer Venus altimeter, Earth-based radar observatories, and the Venera 15-16 orbital imaging radars provided views of large-scale tectonic features on Venus at ever-increasing resolution, the radar images from Magellan constitute an improvement in resolution of at least an order of magnitude over the best previously available. A summary of early Magellan observations of tectonic features on Venus was published, but data available at that time were restricted to the first month of mapping and represented only about 15 percent of the surface of the planet. Magellan images and altimetry are now available for more than 95 percent of the Venus surface. Thus a more global perspective may be taken on the styles and distribution of lithospheric deformation on Venus and their implications for the tectonic history of the planet.

Tectonic Summaries for Web-served Earthquake Responses, Southeastern North America

USGS Publications Warehouse

Wheeler, Russell L.

2003-01-01

This report documents the rationale and strategy used to write short summaries of the seismicity and tectonic settings of domains in southeastern North America. The summaries are used in automated responses to notable earthquakes that occur anywhere east of the Rocky Mountains in the United States or Canada. Specifically, the report describes the geologic and tectonic information, data sources, criteria, and reasoning used to determine the content and format of the summaries, for the benefit of geologists or seismologists who may someday need to revise the summaries or write others. These tectonic summaries are designed to be automatically posted on the World Wide Web as soon as an earthquake?s epicenter is determined. The summaries are part of a larger collection of summaries that is planned to cover the world.

Topography, surface properties, and tectonic evolution. [of Venus and comparison with earth

NASA Technical Reports Server (NTRS)

Mcgill, G. E.; Warner, J. L.; Malin, M. C.; Arvidson, R. E.; Eliason, E.; Nozette, S.; Reasenberg, R. D.

1983-01-01

Differences in atmospheric composition, atmospheric and lithospheric temperature, and perhaps mantle composition, suggest that the rock cycle on Venus is not similar to the earth's. While radar data are not consistent with a thick, widespread and porous regolith like that of the moon, wind-transported regolith could be cemented into sedimentary rock that would be indistinguishable from other rocks in radar returns. The elevation spectrum of Venus is strongly unimodal, in contrast to the earth. Most topographic features of Venus remain enigmatic. Two types of tectonic model are proposed: a lithosphere too thick or buoyant to participate in convective flow, and a lithosphere which, in participating in convective flow, implies the existence of plate tectonics. Features consistent with earth-like plate tectonics have not been recognized.

Magnetic anomalies in East Antarctica: a window on major tectonic provinces and their boundaries

USGS Publications Warehouse

Golynsky, A.V.

2007-01-01

An analysis of aeromagnetic data compiled within the Antarctic Digital Magnetic Anomaly Project (ADMAP) yields significant new insight into major tectonic provinces of East Antarctica. Several previously unknown crustal blocks are imaged in the deep interior of the continent, which are interpreted as cratonic nuclei. These cratons are fringed by a large and continuous orogenic belt between Coats Land and Princess Elizabeth Land, with possible branches in the deeper interior of East Antarctica. Most of the crustal provinces and boundaries identified in this study are only in part exposed. More detailed analyses of these crustal provinces and their tectonic boundaries would require systematic acquisition of additional high-resolution magnetic data, because at present the ADMAP database is largely inadequate to address many remaining questions regarding Antarctica’s tectonic evolution.

Tectonics of Europa

NASA Astrophysics Data System (ADS)

Kattenhorn, S. A.; Hurford, T. A.

2007-12-01

This review of Europan tectonics previews a chapter of the forthcoming text "Europa". After the Voyager flyby of the icy moon Europa in 1979, models were developed that attributed pervasive surface fracturing to the effects of tidal forcing due to the gravitational pull of Jupiter. The late 1990s Galileo mission returned high resolution coverage of the surface, allowing a diverse range of tectonic features to be identified. Subsequent description, interpretation, and modeling of these features has resulted in significant developments in five key themes: (1) What drives the tectonics? (2) What are the formation mechanisms of the various types of tectonic features? (3) What are the implications for a subsurface ocean? (4) What is the nature and thickness of the ice shell? (5) Is Europa currently tectonically active? We highlight key developments pertaining to these fundamental issues, focusing on the following elements: (1) Many fracture patterns can be correlated with theoretical stress fields induced by diurnal tidal forcing and long-term effects of nonsynchronous rotation of the ice shell; however, these driving mechanisms alone cannot explain all fracturing. The tectonic fabric has likely been affected by additional contributing effects: tidal despinning, orbital evolution, interior differentiation, polar wander, finite obliquity, stresses due to shell thickening, endogenic forcing by convection and diapirism, and secondary effects driven by strike-slip faulting and plate flexure. (2) Due to the prevalence of global tension, a low lithostatic gradient, and the inherent weakness of ice, tectonic features likely have predominantly extensional primary formation mechanisms (e.g. surface fractures, ridges, and normal faults). There has been no categorical documentation of fracture development by compressive shearing. Even so, the constantly changing nature of the tidal stress field results in shearing reactivation of cracks being important for the morphologic and mechanical development of tectonic features. Hence, strike-slip faults are relatively common. Also, frictional shearing and heating has likely contributed to the construction of edifices along crack margins (i.e., ridges). If Europa has not recently expanded, crustal convergence (although elusive in Galileo images) is required to balance out new surface material created at spreading bands and may be accommodated locally along ridges or convergence bands. (3) Chains of concatenated curved cracks called cycloids provide convincing evidence of a subsurface ocean in that they must be the result of diurnal forcing of sufficient tidal amplitude to break the ice during a large portion of the Europan orbit, suggesting a tidally responding ocean beneath the ice shell. (4) Fracture mechanics reveals that the brittle portion of the ice shell is likely no more than a few km thick, but convection driven diapirism and crater morphologies necessitate a thicker shell overall (up to about 30 km). It is not known if fractures are able to penetrate this entire shell thickness. The brittle layer acts as a stagnant lid to plastic deformation in the ductile portion of the ice shell, resulting in localized brittle deformation. (5) Tectonic resurfacing has dominated the <70 my of visible geologic history. No evidence exists that Europa is currently tectonically active; however, this may be more a failing of the current state of the science rather than a lack of probability. A tectonically based answer to this question lies in a thorough analysis of geologically young surface fractures but would benefit from far more extensive coverage of the surface via a return mission to Europa.

Mineral-deposit models for northeast Asia, Chapter 3 in Metallogenesis and tectonics of northeast Asia

USGS Publications Warehouse

Obolenskiy, Alexander A.; Rodionov, Sergei M.; Ariunbileg, Sodov; Dejidmaa, Gunchin; Distanov, Elimir G.; Dorjgotov, Dangindorjiin; Gerel, Ochir; Hwang, Duk-Hwan; Sun, Fengyue; Gotovsuren, Ayurzana; Letunov, Sergei N.; Li, Xujun; Nokleberg, Warren J.; Ogasawara, Masatsugu; Seminsky, Zhan V.; Smelov, Akexander P.; Sotnikov, Vitaly I.; Spiridonov, Alexander A.; Zorina, Lydia V.; Yan, Hongquan

2010-01-01

The major purposes of this chapter are to provide (1) an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia for readers who are unfamiliar with the region, (2) a general scientific introduction to the succeeding chapters of this volume, and (3) an overview of the methodology of metallogenic and tectonic analysis used in this study. We also describe how a high-quality metallogenic and tectonic analysis, including construction of an associated metallogenic-tectonic model will greatly benefit other mineral resource studies, including synthesis of mineral-deposit models; improve prediction of undiscovered mineral deposit as part of a quantitative mineral-resource-assessment studies; assist land-use and mineral-exploration planning; improve interpretations of the origins of host rocks, mineral deposits, and metallogenic belts, and suggest new research. Research on the metallogenesis and tectonics of such major regions as Northeast Asia (eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (the Russian Far East, Alaska, and the Canadian Cordillera) requires a complex methodology including (1) definitions of key terms, (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions, (3) compilation of a mineral-deposit database that enables a determination of mineral-deposit models and clarification of the relations of deposits to host rocks and tectonic origins, (4) synthesis of a series of mineral-deposit models that characterize the known mineral deposits and inferred undiscovered deposits in the region, (5) compilation of a series of metallogenic-belt belts constructed on the regional geologic base map, and (6) construction of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis presented here is based on publications of the major international collaborative studies of the metallogenesis and tectonics of Northeast Asia that have been led by the U.S. Geological Survey (USGS). These studies have produced two broad types of publications (1) a series of regional geologic, mineral-deposit, and metallogenic-belt maps, with companion descriptions of the region, and (2) a suite of metallogenic and tectonic analyses of the same region. The study area consists of eastern Russia (most of eastern Siberia and the Russian Far East), Mongolia, northern China, South Korea, Japan, and adjacent offshore areas. The major cooperative agencies are the Russian Academy of Sciences; the Academy of Sciences of the Sakha Republic (Yakutia); VNIIOkeangeologia and Ministry of Natural Resources of the Russian Federation; the Mongolian Academy of Sciences; the Mongolian University of Science and Technology; the Mongolian National University; Jilin University, Changchun, People?s Republic of China, the China Geological Survey; the Korea Institute of Geosciences and Mineral Resources; the Geological Survey of Japan/AIST; the University of Texas, Arlington, and the U.S. Geological Survey (USGS). This study builds on and extends the data and interpretations from a previous project on the Major Mineral Deposits, Metallogenesis, and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera conducted by the USGS, the Russian Academy of Sciences, the Alaska Division of Geological and Geophysical Surveys, and the Geological Survey of Canada. The major products of this project were summarized by Naumova and others (2006) and are described in appendix A.

Introduction to Regional Geology, Tectonics, and Metallogenesis of Northeast Asia

USGS Publications Warehouse

Parfenov, Leonid M.; Badarch, Gombosuren; Berzin, Nikolai A.; Hwang, Duk-Hwan; Khanchuk, Alexander I.; Kuzmin, Mikhail I.; Nokleberg, Warren J.; Obolenskiy, Alexander O.; Ogasawara, Masatsugu; Prokopiev, Andrei V.; Rodionov, Sergey M.; Smelov, Alexander P.; Yan, Hongquan

2007-01-01

This introduction presents an overview of the regional geology, tectonics, and metallogenesis of Northeast Asia. The major purposes are to provide a relatively short summary of these features for readers who are unfamiliar with Northeast Asia; a general scientific introduction for the succeeding chapters of this volume; and an overview of the methodology of metallogenic and tectonic analysis employed for Northeast Asia. The introduction also describes how a high-quality metallogenic and tectonic analysis, including synthesis of an associated metallogenic-tectonic model will greatly benefit refinement of mineral deposit models and deposit genesis; improvement of assessments of undiscovered mineral resources as part of quantitative mineral resource assessment studies; land-use and mineral exploration planning; improvement of interpretations of the origins of host rocks, mineral deposits, and metallogenic belts; and suggestions for new research. The compilation, synthesis, description, and interpretation of metallogenesis and tectonics of major regions, such as Northeast Asia (Eastern Russia, Mongolia, northern China, South Korea, and Japan) and the Circum-North Pacific (Russian Far East, Alaska, and Canadian Cordillera) requires a complex methodology. The methodology includes: (1) definitions of key terms; (2) compilation of a regional geologic base map that can be interpreted according to modern tectonic concepts and definitions; (3) compilation of a mineral deposit database that enables the determination of mineral deposit models, and relations of deposits to host rocks and tectonic origins; (4) synthesis of a series of mineral deposit models that characterize the known mineral deposits and inferred undiscovered deposits of the region; (5) compilation of a series of maps of metallogenic belts constructed on the regional geologic base map; and (6) formulation of a unified metallogenic and tectonic model. The summary of regional geology and metallogenesis in this introduction is based on publications of the major international collaborative studies of the metallogenesis and tectonics of Northeast Asia that were led by the U.S. Geological Survey. These studies have produced two broad types of publications. One type is a series of regional geologic, mineral deposit, and metallogenic belt maps and companion descriptions for the regions. Examples of major publications of this type are Obolenskiy and others (2003a, b, 2004), Parfenov and others (2003, 2004a, b), Nokleberg and others (2004), Rodionov and others (2004), and Naumova and others (2006). The other type is a suite of metallogenic and tectonic analyses of these same regions. Examples of major publications of this type are Rodionov and others (2004), Nokleberg and others (2000, 2004, 2005), and Naumova and others (2006). The Northeast Asia project area consists of eastern Russia (most of Siberia and most of the Russian Far East), Mongolia, Northern China, South Korea, Japan, and adjacent offshore areas. This area is approximately bounded by 30 to 82? N. latitude and 75 to 144? E. longitude. The major participating agencies are the Russian Academy of Sciences, Academy of Sciences of the Sakha Republic (Yakutia), VNIIOkeangeologia and Ministry of Natural Resources of the Russian Federation, Mongolian Academy of Sciences, Mongolian University of Science and Technology, Mongolian National University, Jilin University, Changchun, China, the China Geological Survey, the Korea Institute of Geosciences and Mineral Resources, the Geological Survey of Japan/AIST, University of Texas Arlington, and the U.S. Geological Survey. The Northeast Asia project extends and build on data and interpretations from a previous project on the Major Mineral Deposits, Metallogenesis, and Tectonics of the Russian Far East, Alaska, and the Canadian Cordillera that was conducted by the USGS, the Russian Academy of Sciences, the Alaska Division of Geological and Geophysical Surveys,

From P-T-age to secular change and global tectonic regimes (or Essene in reverse - from granulites to blueschists and eclogites over time)

NASA Astrophysics Data System (ADS)

Brown, M.

2006-12-01

Essene's contributions began pre-plate tectonics more than 40 years ago; they range from mineralogy to tectonics, from experiments and thermobarometry to elements and isotopes, and from the Phanerozoic to the Precambrian. Eric is a true polymath! Assessing the P-T conditions and age distribution of crustal metamorphism is an important step in evaluating secular change in tectonic regimes and geodynamics. In general, Archean rocks exhibit moderate-P - moderate-to-high-T facies series metamorphism (greenstone belts and granulite terranes); neither blueschists nor any record of deep continental subduction and return are documented and only one example of granulite facies ultrahigh-temperature metamorphism is reported. Granulite facies ultrahigh temperature metamorphism (G-UHTM) is documented in the rock record predominantly from Neoarchean to Cambrian, although G-UHTM facies series rocks may be inferred at depth in younger orogenic systems. The first occurrence of G-UHTM in the rock record signifies a change in geodynamics that generated transient sites of very high heat flow. Many G-UHTM belts may have developed in settings analogous to modern continental backarcs. On a warmer Earth, the formation and breakup of supercontinents, particularly by extroversion, which involved destruction of ocean basins floored by thinner lithosphere, may have generated hotter continental backarcs than those around the modern Pacific rim. Medium-temperature eclogite - high-pressure granulite metamorphism (E-HPGM) also is first recognized in the Neoarchean rock record, and occurs at intervals throughout the Proterozoic and Paleozoic rock record. E- HPGM belts are complementary to G-UHTM belts, and are generally inferred to record subduction-to-collision orogenesis. Blueschists become evident in the Neoproterozoic rock record; lawsonite blueschists and eclogites (high-pressure metamorphism, HPM), and ultrahigh pressure metamorphism (UHPM) characterized by coesite or diamond are predominantly Phanerozoic phenomena. HPM-UHPM registers low thermal gradients and deep subduction of continental crust during the early stage of the collision process in Phanerozoic subduction-to-collision orogens. Although counterintuitive, many HPM-UHPM belts appear to have developed by closure of small ocean basins in the process of accretion of a continental terrane during a period of supercontinent introversion (Wilson cycle ocean basin opening and closing). A duality of metamorphic belts - reflecting a duality of thermal regimes - appears in the record only since the Neoarchean Era. A duality of thermal regimes is the hallmark of modern plate tectonics and the duality of metamorphic belts is the characteristic imprint of plate tectonics in the rock record. The occurrence of both G- UHTM and E-HPGM belts since the Neoarchean manifests the onset of a `Proterozoic plate tectonics regime', although the style of tectonics likely involved differences from modern Earth. Although the style of Proterozoic subduction remains cryptic, the change in tectonic regime whereby interactions between discrete lithospheric plates generated tectonic settings with contrasting thermal regimes was a landmark event in Earth history. The `Proterozoic plate tectonics regime' evolved during a Neoproterozoic transition to the `modern plate tectonics regime' characterized by colder subduction, and subduction of continental crust deep into the mantle and its (partial) return from depths of up to 300 km, as chronicled by the appearance of blueschists and HPM-UHPM in the rock record.

An Intracratonic Record of North American Tectonics

NASA Astrophysics Data System (ADS)

Lovell, Thomas Rudolph

Investigating how continents change throughout geologic time provides insight into the underlying plate tectonic process that shapes our world. Researchers aiming to understand plate tectonics typically investigate records exposed at plate margins, as these areas contain direct structural and stratigraphic information relating to tectonic plate interaction. However, these margins are also susceptible to destruction, as orogenic processes tend to punctuate records of plate tectonics. In contrast, intracratonic basins are long-lived depressions located inside cratons, shielded from the destructive forces associated with the plate tectonic process. The ability of cratonic basins to preserve sedimentological records for extended periods of geologic time makes them candidates for recording long term changes in continents driven by tectonics and eustacy. This research utilizes an intracratonic basin to better understand how the North American continent has changed throughout Phanerozoic time. This research resolves geochronologic, thermochronologic, and sedimentologic changes throughout Phanerozoic time (>500 Ma) within the intracratonic Illinois Basin detrital record. Core and outcrop sampling provide the bulk of material upon which detrital zircon geochronologic, detrital apatite thermochronologic, and thin section petrographic analyses were performed. Geochronologic evidence presented in Chapters 2 and 3 reveal the Precambrian - Cretaceous strata of the intracratonic Illinois Basin yield three detrital zircon U-Pb age assemblages. Lower Paleozoic strata yield ages corresponding to predominantly cratonic sources (Archean - Mesoproterozoic). In contrast, Middle - Upper Paleozoic strata have a dominant Appalachian orogen (Neoproterozoic - Paleozoic) signal. Cretaceous strata yield similar ages to underlying Upper Paleozoic strata. We conclude that changes in the provenance of Illinois Basin strata result from eustatic events and tectonic forcings. This evidence demonstrates that changes in the detrital record of the Illinois Basin coincide with well-documented, major tectonic and eustatic events that altered and shaped North American plate margins. Chapter 4 presents 24 apatite (U-Th)/He (AHe) ages (3 - 423 Ma) taken from subsurface Cambrian and Pennsylvanian sandstones in the Illinois Basin. Time-temperature simulations used to reproduce these ages predict a basin thermal history with a maximum temperature of 170°C in post-Pennsylvanian time followed by Mesozoic cooling at 0.3°C/Myr. These thermal simulations suggest 3 km of additional post-Pennsylvanian burial (assuming 30°C/km geotherm) followed by subsequent Mesozoic - Cenozoic removal. This burial-exhumation history is concurrent with Late Mesozoic tectoniceustatic fluctuations, including Atlantic and Gulf of Mexico opening, rejuvenation of the Appalachian region, and Gulf of Mexico sediment influx, and the Cretaceous high sea level stand. The Geochronologic and thermochronologic evidence presented in the following chapters suggests the Illinois Basin potentially contains a more robust record of North American tectonics than previously thought. These observations provide a new perspective on the utility of intracratonic basins in understanding long term changes to continental bodies.

Imaging different components of a tectonic tremor sequence in southwestern Japan using an automatic statistical detection and location method

NASA Astrophysics Data System (ADS)

Poiata, Natalia; Vilotte, Jean-Pierre; Bernard, Pascal; Satriano, Claudio; Obara, Kazushige

2018-06-01

In this study, we demonstrate the capability of an automatic network-based detection and location method to extract and analyse different components of tectonic tremor activity by analysing a 9-day energetic tectonic tremor sequence occurring at the downdip extension of the subducting slab in southwestern Japan. The applied method exploits the coherency of multiscale, frequency-selective characteristics of non-stationary signals recorded across the seismic network. Use of different characteristic functions, in the signal processing step of the method, allows to extract and locate the sources of short-duration impulsive signal transients associated with low-frequency earthquakes and of longer-duration energy transients during the tectonic tremor sequence. Frequency-dependent characteristic functions, based on higher-order statistics' properties of the seismic signals, are used for the detection and location of low-frequency earthquakes. This allows extracting a more complete (˜6.5 times more events) and time-resolved catalogue of low-frequency earthquakes than the routine catalogue provided by the Japan Meteorological Agency. As such, this catalogue allows resolving the space-time evolution of the low-frequency earthquakes activity in great detail, unravelling spatial and temporal clustering, modulation in response to tide, and different scales of space-time migration patterns. In the second part of the study, the detection and source location of longer-duration signal energy transients within the tectonic tremor sequence is performed using characteristic functions built from smoothed frequency-dependent energy envelopes. This leads to a catalogue of longer-duration energy sources during the tectonic tremor sequence, characterized by their durations and 3-D spatial likelihood maps of the energy-release source regions. The summary 3-D likelihood map for the 9-day tectonic tremor sequence, built from this catalogue, exhibits an along-strike spatial segmentation of the long-duration energy-release regions, matching the large-scale clustering features evidenced from the low-frequency earthquake's activity analysis. Further examination of the two catalogues showed that the extracted short-duration low-frequency earthquakes activity coincides in space, within about 10-15 km distance, with the longer-duration energy sources during the tectonic tremor sequence. This observation provides a potential constraint on the size of the longer-duration energy-radiating source region in relation with the clustering of low-frequency earthquakes activity during the analysed tectonic tremor sequence. We show that advanced statistical network-based methods offer new capabilities for automatic high-resolution detection, location and monitoring of different scale-components of tectonic tremor activity, enriching existing slow earthquakes catalogues. Systematic application of such methods to large continuous data sets will allow imaging the slow transient seismic energy-release activity at higher resolution, and therefore, provide new insights into the underlying multiscale mechanisms of slow earthquakes generation.

Imaging different components of a tectonic tremor sequence in southwestern Japan using an automatic statistical detection and location method

NASA Astrophysics Data System (ADS)

Poiata, Natalia; Vilotte, Jean-Pierre; Bernard, Pascal; Satriano, Claudio; Obara, Kazushige

2018-02-01

In this study, we demonstrate the capability of an automatic network-based detection and location method to extract and analyse different components of tectonic tremor activity by analysing a 9-day energetic tectonic tremor sequence occurring at the down-dip extension of the subducting slab in southwestern Japan. The applied method exploits the coherency of multi-scale, frequency-selective characteristics of non-stationary signals recorded across the seismic network. Use of different characteristic functions, in the signal processing step of the method, allows to extract and locate the sources of short-duration impulsive signal transients associated with low-frequency earthquakes and of longer-duration energy transients during the tectonic tremor sequence. Frequency-dependent characteristic functions, based on higher-order statistics' properties of the seismic signals, are used for the detection and location of low-frequency earthquakes. This allows extracting a more complete (˜6.5 times more events) and time-resolved catalogue of low-frequency earthquakes than the routine catalogue provided by the Japan Meteorological Agency. As such, this catalogue allows resolving the space-time evolution of the low-frequency earthquakes activity in great detail, unravelling spatial and temporal clustering, modulation in response to tide, and different scales of space-time migration patterns. In the second part of the study, the detection and source location of longer-duration signal energy transients within the tectonic tremor sequence is performed using characteristic functions built from smoothed frequency-dependent energy envelopes. This leads to a catalogue of longer-duration energy sources during the tectonic tremor sequence, characterized by their durations and 3-D spatial likelihood maps of the energy-release source regions. The summary 3-D likelihood map for the 9-day tectonic tremor sequence, built from this catalogue, exhibits an along-strike spatial segmentation of the long-duration energy-release regions, matching the large-scale clustering features evidenced from the low-frequency earthquake's activity analysis. Further examination of the two catalogues showed that the extracted short-duration low-frequency earthquakes activity coincides in space, within about 10-15 km distance, with the longer-duration energy sources during the tectonic tremor sequence. This observation provides a potential constraint on the size of the longer-duration energy-radiating source region in relation with the clustering of low-frequency earthquakes activity during the analysed tectonic tremor sequence. We show that advanced statistical network-based methods offer new capabilities for automatic high-resolution detection, location and monitoring of different scale-components of tectonic tremor activity, enriching existing slow earthquakes catalogues. Systematic application of such methods to large continuous data sets will allow imaging the slow transient seismic energy-release activity at higher resolution, and therefore, provide new insights into the underlying multi-scale mechanisms of slow earthquakes generation.

Global views of Venus from Magellan

NASA Technical Reports Server (NTRS)

Arvidson, R. E.; Phillips, R. J.; Izenberg, N.

1992-01-01

Magellan data for Venus reveal a planet with a great diversity of volcanic and tectonic landforms, with good evidence of continuing volcanism and tectonism. Weathering, mass wasting and wind erosion and deposition have modified the surface only to the extent of a few meters, thereby preserving an excellent record of tectonic and volcanic processes on a terrestrial-size planet. All cycle 1 mosaics, radiometry, and altimeter data will be made available through the Planetary Data System and the National Space Science Data Center.

Tectonics and Volcanism of East Africa as Seen Using Remote Sensing Imagery

NASA Technical Reports Server (NTRS)

Hutt, Duncan John

1996-01-01

The East African Rift is the largest area of active continental geology. The tectonics of this area has been studied with remote sensing data, including AVHRR, Landsat MSS and TM, SPOT, and electronic still camera from Shuttle. Lineation trends have been compared to centers of volcanic and earthquake activity as well as the trends shown on existing geologic maps. Remote sensing data can be used effectively to reveal and analyze significant tectonic features in this area.

New evidence for global tectonic zones on Venus

NASA Technical Reports Server (NTRS)

Kozak, Richard C.; Schaber, Gerald G.

1989-01-01

Venera 15 and 16 spacecraft images show clear evidence of major crustal disruptions on Venus which have been interpreted to indicate crustal divergence. Complementary to the divergent zones are mountain belts that border the continent-like high terrains. The requisite transcurrent motions appear to be manifested as diffuse shear zones. The rift zones form an interconnected transpolar system which ties in with previously recognized equatorial disruption zones, suggesting a global tectonic network. Several independent lines of evidence suggest that the tectonism may be geologically young.

Lithospheric Models of the Middle East to Improve Seismic Source Parameter Determination/Event Location Accuracy

DTIC Science & Technology

2012-09-01

State Award Nos. DE-AC52-07NA27344/24.2.3.2 and DOS_SIAA-11-AVC/NMA-1 ABSTRACT The Middle East is a tectonically complex and seismically...active region. The ability to accurately locate earthquakes and other seismic events in this region is complicated by tectonics , the uneven...and seismic source parameters show that this activity comes from tectonic events. This work is informed by continuous or event-based regional

The Keck keyword layer

NASA Technical Reports Server (NTRS)

Conrad, A. R.; Lupton, W. F.

1992-01-01

Each Keck instrument presents a consistent software view to the user interface programmer. The view consists of a small library of functions, which are identical for all instruments, and a large set of keywords, that vary from instrument to instrument. All knowledge of the underlying task structure is hidden from the application programmer by the keyword layer. Image capture software uses the same function library to collect data for the image header. Because the image capture software and the instrument control software are built on top of the same keyword layer, a given observation can be 'replayed' by extracting keyword-value pairs from the image header and passing them back to the control system. The keyword layer features non-blocking as well as blocking I/O. A non-blocking keyword write operation (such as setting a filter position) specifies a callback to be invoked when the operation is complete. A non-blocking keyword read operation specifies a callback to be invoked whenever the keyword changes state. The keyword-callback style meshes well with the widget-callback style commonly used in X window programs. The first keyword library was built for the two Keck optical instruments. More recently, keyword libraries have been developed for the infrared instruments and for telescope control. Although the underlying mechanisms used for inter-process communication by each of these systems vary widely (Lick MUSIC, Sun RPC, and direct socket I/O, respectively), a basic user interface has been written that can be used with any of these systems. Since the keyword libraries are bound to user interface programs dynamically at run time, only a single set of user interface executables is needed. For example, the same program, 'xshow', can be used to display continuously the telescope's position, the time left in an instrument's exposure, or both values simultaneously. Less generic tools that operate on specific keywords, for example an X display that controls optical instrument exposures, have also been written using the keyword layer.

Maps, Plates, and Mount Saint Helens.

ERIC Educational Resources Information Center

Lary, Barbara E.; Krockover, Gerald H.

1987-01-01

Describes a laboratory activity on plate tectonics which focuses on the connection between plate tectonics and the different types of volcanoes. Provides questions for discussion and includes suggestions for extending the activity. (ML)

BioTCM-SE: a semantic search engine for the information retrieval of modern biology and traditional Chinese medicine.

PubMed

Chen, Xi; Chen, Huajun; Bi, Xuan; Gu, Peiqin; Chen, Jiaoyan; Wu, Zhaohui

2014-01-01

Understanding the functional mechanisms of the complex biological system as a whole is drawing more and more attention in global health care management. Traditional Chinese Medicine (TCM), essentially different from Western Medicine (WM), is gaining increasing attention due to its emphasis on individual wellness and natural herbal medicine, which satisfies the goal of integrative medicine. However, with the explosive growth of biomedical data on the Web, biomedical researchers are now confronted with the problem of large-scale data analysis and data query. Besides that, biomedical data also has a wide coverage which usually comes from multiple heterogeneous data sources and has different taxonomies, making it hard to integrate and query the big biomedical data. Embedded with domain knowledge from different disciplines all regarding human biological systems, the heterogeneous data repositories are implicitly connected by human expert knowledge. Traditional search engines cannot provide accurate and comprehensive search results for the semantically associated knowledge since they only support keywords-based searches. In this paper, we present BioTCM-SE, a semantic search engine for the information retrieval of modern biology and TCM, which provides biologists with a comprehensive and accurate associated knowledge query platform to greatly facilitate the implicit knowledge discovery between WM and TCM.

BioTCM-SE: A Semantic Search Engine for the Information Retrieval of Modern Biology and Traditional Chinese Medicine

PubMed Central

Chen, Xi; Chen, Huajun; Bi, Xuan; Gu, Peiqin; Chen, Jiaoyan; Wu, Zhaohui

2014-01-01

Understanding the functional mechanisms of the complex biological system as a whole is drawing more and more attention in global health care management. Traditional Chinese Medicine (TCM), essentially different from Western Medicine (WM), is gaining increasing attention due to its emphasis on individual wellness and natural herbal medicine, which satisfies the goal of integrative medicine. However, with the explosive growth of biomedical data on the Web, biomedical researchers are now confronted with the problem of large-scale data analysis and data query. Besides that, biomedical data also has a wide coverage which usually comes from multiple heterogeneous data sources and has different taxonomies, making it hard to integrate and query the big biomedical data. Embedded with domain knowledge from different disciplines all regarding human biological systems, the heterogeneous data repositories are implicitly connected by human expert knowledge. Traditional search engines cannot provide accurate and comprehensive search results for the semantically associated knowledge since they only support keywords-based searches. In this paper, we present BioTCM-SE, a semantic search engine for the information retrieval of modern biology and TCM, which provides biologists with a comprehensive and accurate associated knowledge query platform to greatly facilitate the implicit knowledge discovery between WM and TCM. PMID:24772189

A novel architecture for information retrieval system based on semantic web

NASA Astrophysics Data System (ADS)

Zhang, Hui

2011-12-01

Nowadays, the web has enabled an explosive growth of information sharing (there are currently over 4 billion pages covering most areas of human endeavor) so that the web has faced a new challenge of information overhead. The challenge that is now before us is not only to help people locating relevant information precisely but also to access and aggregate a variety of information from different resources automatically. Current web document are in human-oriented formats and they are suitable for the presentation, but machines cannot understand the meaning of document. To address this issue, Berners-Lee proposed a concept of semantic web. With semantic web technology, web information can be understood and processed by machine. It provides new possibilities for automatic web information processing. A main problem of semantic web information retrieval is that when these is not enough knowledge to such information retrieval system, the system will return to a large of no sense result to uses due to a huge amount of information results. In this paper, we present the architecture of information based on semantic web. In addiction, our systems employ the inference Engine to check whether the query should pose to Keyword-based Search Engine or should pose to the Semantic Search Engine.

Drug-device combination products in the twenty-first century: epinephrine auto-injector development using human factors engineering.

PubMed

Edwards, Eric S; Edwards, Evan T; Simons, F Estelle R; North, Robert

2015-05-01

The systematic application of human factors engineering (HFE) principles to the development of drug-device combination products, including epinephrine auto-injectors (EAIs), has the potential to improve the effectiveness and safety of drug administration. A PubMed search was performed to assess the role of HFE in the development of drug-device combination products. The following keywords were used in different combinations: 'human factors engineering,' 'human factors,' 'medical products,' 'epinephrine/adrenaline auto-injector,' 'healthcare' and 'patient safety.' This review provides a summary of HFE principles and their application to the development of drug-device combination products as advised by the US FDA. It also describes the HFE process that was applied to the development of Auvi-Q, a novel EAI, highlighting specific steps that occurred during the product-development program. For drug-device combination products, device labeling and usability are critical and have the potential to impact clinical outcomes. Application of HFE principles to the development of drug-delivery devices has the potential to improve product quality and reliability, reduce risk and improve patient safety when applied early in the development process. Additional clinical and real-world studies will confirm whether the application of HFE has helped to develop an EAI that better meets the needs of patients at risk of anaphylaxis.

Using the salt tectonics as a proxy to reveal post-rift active crustal tectonics: The example of the Eastern Sardinian margin

NASA Astrophysics Data System (ADS)

Lymer, Gaël; Vendeville, Bruno; Gaullier, Virginie; Chanier, Frank; Gaillard, Morgane

2017-04-01

The Western Tyrrhenian Basin, Mediterranean Sea, is a fascinating basin in terms of interactions between crustal tectonics, salt tectonics and sedimentation. The METYSS (Messinian Event in the Tyrrhenian from Seismic Study) project is based on 2100 km of HR seismic data acquired in 2009 and 2011 along the Eastern Sardinian margin. The main aim is to study the Messinian Salinity Crisis (MSC) in the Western Tyrrhenian Basin, but we also investigate the thinning processes of the continental crust and the timing of crustal vertical motions across this complex domain. Our first results allowed us to map the MSC seismic markers and to better constrain the timing of the rifting, which ended before the MSC across the upper and middle parts of the margin. We also evidenced that crustal activity persisted long after the end of rifting. This has been particularly observed on the upper margin, where several normal faults and a surprising compressional structure were recently active. In this study we investigate the middle margin, the Cornaglia Terrace, where the Mobile Unit (MU, mobile Messinian salt) accumulated during the MSC and acts as a décollement. Our goal is to ascertain whether or not crustal tectonics existed after the pre-MSC rift. This is a challenge where the MU is thick, because potential basement deformations could be first accommodated by the MU and therefore would not find any expression in the supra-salt layers (Upper Unit, UU and Plio-Quaternary, PQ). However our investigations clearly reveal interactions between crustal and salt tectonics along the margin. We thus evidence gravity gliding of the salt and its brittle sedimentary cover along basement slopes generated by the post-MSC tilting of some basement blocks bounded by crustal normal faults, formerly due to the rifting. Another intriguing structure also got our interest. It corresponds to a wedge-shaped of MU located in a narrow N-S half graben bounded to the west by a major, east-verging, crustal normal fault. Below the MU, the sediments thicken toward the fault. The top of the MU is sub-horizontal and the supra-salt layers are sub-horizontal. At a first glance this geometry would suggest that the pre-salt unit and the MU are syn-tectonic and that nothing happened after Messinian times. However some subtle evidence of deformations in the UU and PQ (an anticline to the west and a small west-verging normal fault in the east) imply that some crustal tectonics activity persisted after the end of the rifting. To understand why the salt unit is wedge-shaped, we considered several scenarii that we tested with physical modelling. We demonstrate that this structure is related to the post-rift activity of the major crustal normal fault, whose vertical motion has been cushioned by lateral flow of an initially tabular salt layer, which thinned upslope and inflated downslope, keeping the overlying sediments remained sub-horizontal. Such interactions between thin-skinned and thick-skinned tectonics highlight how the analysis of the salt tectonics is a powerful tool to reveal recent deep crustal tectonics in the Western Mediterranean Basin.

A review of the tectonic evolution of the Northern Pacific and adjacent Cordilleran Orogen

NASA Astrophysics Data System (ADS)

Jakob, Johannes; Gaina, Carmen; Johnston, Stephen T.

2014-05-01

Numerous plate kinematic models for the North Pacific realm have been developed since the advent of plate tectonics in the early seventies (e.g Atwater (1970), Mammerickx and Sharman (1988)). Although published kinematic models are consistent with the broad scale features of the North Pacific, the link between plate motions and the evolution of the North American Cordillera remains poorly understood. Part of the problem lies in conflicting interpretations of geological versus paleomagnetic data sets, with the result being a lack of consensus regarding: the paleolocation of key geological units; the paleogeography of terrane formation and amalgamation; the motion, boundaries and even existence of oceanic plates; and the character (e.g. trend of subduction) and position of plate boundaries within the northern Pacific basin. Remnants of the Farallon and Kula plates, and some short-lived microplates, demonstrate the complicated tectonic evolution of the oceanic realm west of the North American margin (e.g. Rea and Dixon (1983); McCrory and Wilson (2013); Shephard et al. (2013)). The creation and destruction of major tectonic plates and microplates has presumably left a record in the Cordilleran orogen of western North America. However, working backward from the geological relationships to plate reconstructions remains difficult. Here we investigate the relationship between the plate motions of the Pacific Ocean and the terrane movements in the North American Cordillera by revising the marine magnetic and gravity anomalies of the northern Pacific. In particular, we reevaluate plate boundaries at times of major changes in plate geometry of the Pacific, Kula, Chinook and Farallon plates from C34n onward. Our focus is also on the plate geometries of the Resurrection, Eshamy and Siletz-Crescent plates during the time between anomaly C26 and C12, and the links between plate interactions and on-shore tectonic events recorded in the geological record of Vancouver Island, including the accretion of the Pacific Rim and Crescent terranes to Wrangellia between C25 and C18. References: Atwater, T. (1970). Implications of plate tectonics for the Cenozoic tectonic evolution of western North America. Geological Society of America Bulletin, 81, 3513-3536. McCrory, P. a., & Wilson, D. S. (2013). A kinematic model for the formation of the Siletz-Crescent forearc terrane by capture of coherent fragments of the Farallon and Resurrection plates. Tectonics, 32, 1-19. doi:10.1002/tect.20045 Rea, D. K., & Dixon, J. M. (1983). Late Cretaceous and Paleogene tectonic evolution of the North Pacific Ocean. Earth and Planetary Science Letters, 65, 145-166. Shephard, G. E., Müller, R. D., & Seton, M. (2013). The tectonic evolution of the Arctic since Pangea breakup: Integrating constraints from surface geology and geophysics with mantle structure. Earth-Science Reviews, 124, 148-183. doi:10.1016/j.earscirev.2013.05.012 Mammerickx, J., & Sharman, G. F. (1988). Tectonic evolution of the North Pacific during the Cretaceous quiet period. Journal of Geophysical Research, 93(B4), 3009-3024. doi:10.1029/JB093iB04p03009

Towards An Engineering Discipline of Computational Security

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mili, Ali; Sheldon, Frederick T; Jilani, Lamia Labed

2007-01-01

George Boole ushered the era of modern logic by arguing that logical reasoning does not fall in the realm of philosophy, as it was considered up to his time, but in the realm of mathematics. As such, logical propositions and logical arguments are modeled using algebraic structures. Likewise, we submit that security attributes must be modeled as formal mathematical propositions that are subject to mathematical analysis. In this paper, we approach this problem by attempting to model security attributes in a refinement-like framework that has traditionally been used to represent reliability and safety claims. Keywords: Computable security attributes, survivability, integrity,more » dependability, reliability, safety, security, verification, testing, fault tolerance.« less

How to write a research proposal?

PubMed Central

Sudheesh, K; Duggappa, Devika Rani; Nethra, SS

2016-01-01

Writing the proposal of a research work in the present era is a challenging task due to the constantly evolving trends in the qualitative research design and the need to incorporate medical advances into the methodology. The proposal is a detailed plan or ‘blueprint’ for the intended study, and once it is completed, the research project should flow smoothly. Even today, many of the proposals at post-graduate evaluation committees and application proposals for funding are substandard. A search was conducted with keywords such as research proposal, writing proposal and qualitative using search engines, namely, PubMed and Google Scholar, and an attempt has been made to provide broad guidelines for writing a scientifically appropriate research proposal. PMID:27729688

The Outer Space as an Educational Motivation

NASA Astrophysics Data System (ADS)

Pérez-Pérez, Melquíades; Hernández-López, Montserrat

2017-06-01

STEAM is an educational approach to learning that uses Science, Technology, Engineering, the Arts and Mathematics as access points for guiding student inquiry, dialogue, and critical thinking. The end results are students who take thoughtful risks, engage in experiential learning, persist in problem-solving, embrace collaboration, and work through the creative process. The Outer Space is a window to the past and the future of our travel around the history of the Universe and can be used as a educational tool in primary and secondary education. This paper talks about the integration of the resources of European Space Agency, Space Awareness, Nuclio, Scientix and Schoolnet as motivation to integrate STEAM methodology in secondary education. Keywords: STEAM, outer space, motivation, methodology

Extracting Inter-business Relationship from World Wide Web

NASA Astrophysics Data System (ADS)

Jin, Yingzi; Matsuo, Yutaka; Ishizuka, Mitsuru

Social relation plays an important role in a real community. Interaction patterns reveal relations among actors (such as persons, groups, companies), which can be merged into valuable information as a network structure. In this paper, we propose a new approach to extract inter-business relationship from the Web. Extraction of relation between a pair of companies is realized by using a search engine and text processing. Since names of companies co-appear coincidentaly on the Web, we propose an advanced algorithm which is characterized by addition of keywords (or we call relation words) to a query. The relation words are obtained from either an annotated corpus or the Web. We show some examples and comprehensive evaluations on our approach.

Fissure near Cerberus Fossae with Tectonic Morphologies

NASA Image and Video Library

2014-01-15

The linearity of the volcanic vent shown in this image observed by NASA Mars Reconnaissance Orbiter, in conjunction with evidence of lava flow from the vent, suggests control by combined volcano-tectonic processes.

Workshop on the Tectonic Evolution of Greenstone Belts (supplement containing abstracts of invited talks and late abstracts)

NASA Technical Reports Server (NTRS)

1986-01-01

Topics addressed include: greenstone belt tectonics, thermal constaints, geological structure, rock components, crustal accretion model, geological evolution, synsedimentary deformation, Archean structures and geological faults.

Escape tectonics and the extrusion of Alaska: Past, present, and future

USGS Publications Warehouse

Redfield, T.F.; Scholl, D. W.; Fitzgerald, P.G.; Beck, M.E.

2007-01-01

The North Pacific Rim is a tectonically active plate boundary zone parts of which may be characterized as a laterally moving orogenic stream. Crustal blocks are transported along large-magnitude strike-slip faults in western Canada and central Alaska toward the Aleutian-Bering Sea subduction zones. Throughout much of the Cenozoic, at and west of its Alaskan nexus, the North Pacific Rim orogenic Stream (NPRS) has undergone tectonic escape. During transport, relatively rigid blocks acquired paleomagnetic rotations and fault-juxtaposed boundaries while flowing differentially through the system, from their original point of accretion and entrainment toward the free face defined by the Aleutian-Bering Sea subduction zones. Built upon classical terrane tectonics, the NPRS model provides a new framework with which to view the mobilistic nature of the western North American plate boundary zone. ?? 2007 The Geological Society of America.

Rheological decoupling at the Moho and implication to Venusian tectonics.

PubMed

Azuma, Shintaro; Katayama, Ikuo; Nakakuki, Tomoeki

2014-03-18

Plate tectonics is largely responsible for material and heat circulation in Earth, but for unknown reasons it does not exist on Venus. The strength of planetary materials is a key control on plate tectonics because physical properties, such as temperature, pressure, stress, and chemical composition, result in strong rheological layering and convection in planetary interiors. Our deformation experiments show that crustal plagioclase is much weaker than mantle olivine at conditions corresponding to the Moho in Venus. Consequently, this strength contrast may produce a mechanical decoupling between the Venusian crust and interior mantle convection. One-dimensional numerical modeling using our experimental data confirms that this large strength contrast at the Moho impedes the surface motion of the Venusian crust and, as such, is an important factor in explaining the absence of plate tectonics on Venus.

Dreaming of Graben in the Labyrinth of the Night

NASA Image and Video Library

2016-06-29

Noctis Labyrinthus is a highly tectonized region immediately to the west of Valles Marineris. It formed when Mars' crust stretched itself apart. In this region, the crust first stretched in a north-south direction (as evidenced by the east-west trending scarp) and then in an east-west direction (as evidenced by the north-south trending smaller scarps). This sort of tectonic stretching creates faults in the crust (cracks along with masses of rock slide. This process is totally unrelated to Earth's plate tectonics.). The lower portions between faults are called "grabens" and the interspersed higher portions are called "horsts." The Basin and Range tectonic province of the western United States is a close Earth analog to Noctis Labyrinthus, which is Latin for "labyrinth of the night." http://photojournal.jpl.nasa.gov/catalog/PIA20740

Rheological decoupling at the Moho and implication to Venusian tectonics

PubMed Central

Azuma, Shintaro; Katayama, Ikuo; Nakakuki, Tomoeki

2014-01-01

Plate tectonics is largely responsible for material and heat circulation in Earth, but for unknown reasons it does not exist on Venus. The strength of planetary materials is a key control on plate tectonics because physical properties, such as temperature, pressure, stress, and chemical composition, result in strong rheological layering and convection in planetary interiors. Our deformation experiments show that crustal plagioclase is much weaker than mantle olivine at conditions corresponding to the Moho in Venus. Consequently, this strength contrast may produce a mechanical decoupling between the Venusian crust and interior mantle convection. One-dimensional numerical modeling using our experimental data confirms that this large strength contrast at the Moho impedes the surface motion of the Venusian crust and, as such, is an important factor in explaining the absence of plate tectonics on Venus. PMID:24638113

Impacts and tectonism in Earth and moon history of the past 3800 million years

NASA Technical Reports Server (NTRS)

Stothers, Richard B.

1992-01-01

The moon's surface, unlike the Earth's, displays a comparatively clear record of its past bombardment history for the last 3800 Myr, the time since active lunar tectonism under the massive premare bombardment ended. From Baldwin's (1987) tabulation of estimated ages for a representative sample of large lunar craters younger than 3800 Ma, six major cratering episodes can be discerned. These six bombardment episodes, which must have affected the Earth too, appear to match in time the six major episodes of orogenic tectonism on Earth, despite typical resolution errors of +/- 100 Myr and the great uncertainties of the two chronologies. Since more highly resolved events during the Cenozoic and Mesozoic Eras suggest the same correlation, it is possible that large impacts have influenced plate tectonics and other aspects of geologic history, perhaps by triggering flood basalt eruptions.

The mantle lithosphere and the Wilson Cycle

NASA Astrophysics Data System (ADS)

Heron, Philip; Pysklywec, Russell; Stephenson, Randell

2017-04-01

In the view of the conventional theory of plate tectonics (e.g., the Wilson Cycle), crustal inheritance is often considered important in tectonic evolution. However, the role of the mantle lithosphere is usually overlooked due to its difficulty to image and uncertainty in rheological makeup. Deep seismic imaging has shown potential scarring in continental mantle lithosphere to be ubiquitous. Recent studies have interpreted mantle lithosphere heterogeneities to be pre-existing structures, and as such linked to the Wilson Cycle and inheritance. In our study, we analyze intraplate deformation driven by mantle lithosphere heterogeneities from ancient Wilson Cycle processes and compare this to crustal inheritance deformation. We present 2-D numerical experiments of continental convergence to generate intraplate deformation, exploring the limits of continental rheology to understand the dominant lithosphere layer across a broad range of geological settings. By implementing a "jelly sandwich" rheology, characteristic of stable continental lithosphere, we find that during compression the strength of the mantle lithosphere is integral in controlling deformation from a structural anomaly. We posit that if the continental mantle is the strongest layer within the lithosphere, then such inheritance may have important implications for the Wilson Cycle. Furthermore, our models show that deformation driven by mantle lithosphere scarring can produce tectonic patterns related to intraplate orogenesis originating from crustal sources, highlighting the need for a more formal discussion of the role of the mantle lithosphere in plate tectonics. We outline the difficulty in unravelling the causes of tectonic deformation, alongside discussing the role of deep lithosphere processes in plate tectonics.

Stratigraphic and structural distribution of reservoirs in Romania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stefanescu, M.O.

1991-08-01

In Romania, there are reservoirs at different levels of the whole Cambrian-Pliocene interval, but only some of these levels have the favorable structural conditions to accumulate hydrocarbons in commercial quantities. These levels are the Devonian, Triassic, Middle Jurassic, Lower Cretaceous (locally including the uppermost Jurassic), Eocene, Oligocene-lower Miocene, middle and upper Miocene, and Pliocene. The productive reservoirs are represented either by carbonate rocks (in Devonian, Middle Triassic and uppermost Jurassic-Lower Cretaceous) or by detrital rocks (in Lower and Upper Triassic, Middle Jurassic, Eocene, Oligocene, Miocene, and Pliocene). From the structural point of view, the Romanian territory is characterized by themore » coexistence both of platforms (East European, Scythian, and Moesian platforms) and of the strongly tectonized orogenes (North Dobrogea and Carpathian orogenes). Each importance crust shortening was followed by the accumulation of post-tectonic covers, some of them being folded during subsequently tectonic movements. The youngest post-tectonic cover is common both for the platforms (foreland) and Carpathian orogene, representing the Carpathian foredeep. Producing reservoirs are present in the East European and Moesian platforms, in the outer Carpathian units (Tarcau and Marginal folds nappes) and in certain post-tectonic covers which fill the Carpathian foredeep and the Transylvanian and Pannonian basins. In the platforms, hydrocarbons accumulated both in calcareous and detrital reservoirs, whereas in the Carpathian units and in their reservoirs, whereas in the Carpathian units and in their post-tectonic covers, hydrocarbons accumulated only in detrital reservoirs.« less

Whole planet coupling between climate, mantle, and core: Implications for rocky planet evolution

NASA Astrophysics Data System (ADS)

Foley, Bradford J.; Driscoll, Peter E.

2016-05-01

Earth's climate, mantle, and core interact over geologic time scales. Climate influences whether plate tectonics can take place on a planet, with cool climates being favorable for plate tectonics because they enhance stresses in the lithosphere, suppress plate boundary annealing, and promote hydration and weakening of the lithosphere. Plate tectonics plays a vital role in the long-term carbon cycle, which helps to maintain a temperate climate. Plate tectonics provides long-term cooling of the core, which is vital for generating a magnetic field, and the magnetic field is capable of shielding atmospheric volatiles from the solar wind. Coupling between climate, mantle, and core can potentially explain the divergent evolution of Earth and Venus. As Venus lies too close to the sun for liquid water to exist, there is no long-term carbon cycle and thus an extremely hot climate. Therefore, plate tectonics cannot operate and a long-lived core dynamo cannot be sustained due to insufficient core cooling. On planets within the habitable zone where liquid water is possible, a wide range of evolutionary scenarios can take place depending on initial atmospheric composition, bulk volatile content, or the timing of when plate tectonics initiates, among other factors. Many of these evolutionary trajectories would render the planet uninhabitable. However, there is still significant uncertainty over the nature of the coupling between climate, mantle, and core. Future work is needed to constrain potential evolutionary scenarios and the likelihood of an Earth-like evolution.

Neotectonics and geomorphic evolution of the northwestern arm of the Yellowstone Tectonic Parabola: Controls on intra-cratonic extensional regimes, southwest Montana

USGS Publications Warehouse

Ruleman, Chester A.; Larsen, Mort; Stickney, Michael C.

2014-01-01

The catastrophic Hebgen Lake earthquake of 18 August 1959 (MW 7.3) led many geoscientists to develop new methods to better understand active tectonics in extensional tectonic regimes that address seismic hazards. The Madison Range fault system and adjacent Hebgen Lake–Red Canyon fault system provide an intermountain active tectonic analog for regional analyses of extensional crustal deformation. The Madison Range fault system comprises fault zones (~100 km in length) that have multiple salients and embayments marked by preexisting structures exposed in the footwall. Quaternary tectonic activity rates differ along the length of the fault system, with less displacement to the north. Within the Hebgen Lake basin, the 1959 earthquake is the latest slip event in the Hebgen Lake–Red Canyon fault system and southern Madison Range fault system. Geomorphic and paleoseismic investigations indicate previous faulting events on both fault systems. Surficial geologic mapping and historic seismicity support a coseismic structural linkage between the Madison Range and Hebgen Lake–Red Canyon fault systems. On this trip, we will look at Quaternary surface ruptures that characterize prehistoric earthquake magnitudes. The one-day field trip begins and ends in Bozeman, and includes an overview of the active tectonics within the Madison Valley and Hebgen Lake basin, southwestern Montana. We will also review geologic evidence, which includes new geologic maps and geomorphic analyses that demonstrate preexisting structural controls on surface rupture patterns along the Madison Range and Hebgen Lake–Red Canyon fault systems.

How did Earth not End up like Venus?

NASA Astrophysics Data System (ADS)

Jellinek, M.; Lenardic, A.; Weller, M. B.

2017-12-01

Recent geodynamic calculations show that terrestrial planets forming with a chondritic initial bulk composition at order 1 AU can evolve to be either "Earth-like" or "Venus-like": Both mobile- and stagnant-lid tectonic regimes are permitted, neither solution is an explicitly stronger attractor and effects related to differences in Sun-Earth distance are irrelevant. What factors might then cause the thermal evolutionary paths of Earth and Venus to diverge dynamically at early times? At what point in Earth's evolution did plate tectonics emerge and when and how did this tectonic mode gain sufficient resilience to persist over much of Earth's evolution? What is the role of volatile cycling and climate: To what extent have the stable climate of Earth and the greenhouse runaway climate of Venus enforced their distinct tectonic regimes over time? In this talk I will explore some of the mechanisms potentially governing the evolutionary divergence of Earth and Venus. I will first review observational constraints that suggest that Earth's entry into the current stable plate tectonic mode was far from assured by 2 Ga. Next I will discuss how models have been used to build understanding of some key dynamical controls. In particular, the probability of "Earth-like" solutions is affected by: 1) small differences in the initial concentrations of heat producing elements (i.e., planetary initial conditions); 2) long-term climate change; and 3) the character of a planet's early evolutionary path (i.e., tectonic hysteresis).

Tectonic evolution of the northern African margin in Tunisia from paleostress data and sedimentary record

NASA Astrophysics Data System (ADS)

Bouaziz, Samir; Barrier, Eric; Soussi, Mohamed; Turki, Mohamed M.; Zouari, Hédi

2002-11-01

A reconstruction of the tectonic evolution of the northern African margin in Tunisia since the Late Permian combining paleostress, tectonic stratigraphic and sedimentary approaches allows the characterization of several major periods corresponding to consistent stress patterns. The extension lasting from the Late Permian to the Middle Triassic is contemporaneous of the rifting related to the break up of Pangea. During Liassic times, regional extensional tectonics originated the dislocation of the initial continental platform. In northern Tunisia, the evolution of the Liassic NE-SW rifting led during Dogger times to the North African passive continental margin, whereas in southern Tunisia, a N-S extension, associated with E-W trending subsiding basins, lasted from the Jurassic until the Early Cretaceous. After an Upper Aptian-Early Albian transpressional event, NE-SW to ENE-WSW trending extensions prevailed during Late Cretaceous in relationship with the general tectonic evolution of the northeastern African plate. The inversions started in the Late Maastrichtian-Paleocene in northern Tunisia, probably as a consequence of the Africa-Eurasia convergence. Two major NW-SE trending compressions occurred in the Late Eocene and in the Middle-Late Miocene alternating with extensional periods in the Eocene, Oligocene, Early-Middle Miocene and Pliocene. The latter compressional event led to the complete inversion of the basins of the northwestern African plate, originating the Maghrebide chain. Such a study, supported by a high density of paleostress data and including complementary structural and stratigraphic approaches, provides a reliable way of determining the regional tectonic evolution.

Integrating EarthScope Data to Constrain the Long-Term Effects of Tectonism on Continental Lithosphere

NASA Astrophysics Data System (ADS)

Porter, R. C.; van der Lee, S.

2017-12-01

One of the most significant products of the EarthScope experiment has been the development of new seismic tomography models that take advantage of the consistent station design, regular 70-km station spacing, and wide aperture of the EarthScope Transportable Array (TA) network. These models have led to the discovery and interpretation of additional compositional, thermal, and density anomalies throughout the continental US, especially within tectonically stable regions. The goal of this work is use data from the EarthScope experiment to better elucidate the temporal relationship between tectonic activity and seismic velocities. To accomplish this, we compile several upper-mantle seismic velocity models from the Incorporated Research Institute for Seismology (IRIS) Earth Model Collaboration (EMC) and compare these to a tectonic age model we compiled using geochemical ages from the Interdisciplinary Earth Data Alliance: EarthChem Database. Results from this work confirms quantitatively that the time elapsed since the most recent tectonic event is a dominant influence on seismic velocities within the upper mantle across North America. To further understand this relationship, we apply mineral-physics models for peridotite to estimate upper-mantle temperatures for the continental US from tomographically imaged shear velocities. This work shows that the relationship between the estimated temperatures and the time elapsed since the most recent tectonic event is broadly consistent with plate cooling models, yet shows intriguing scatter. Ultimately, this work constrains the long-term thermal evolution of continental mantle lithosphere.

Using Grand Challenges For Innovative Teaching in Structural Geology, Geophysics, and Tectonics

NASA Astrophysics Data System (ADS)

McDaris, J. R.; Tewksbury, B. J.; Wysession, M. E.

2012-12-01

An innovative approach to teaching involves using the "Big Ideas" or "Grand Challenges" of a field, as determined by the research community in that area, as the basis for classroom activities. There have been several recent efforts in the areas of structural geology, tectonics, and geophysics to determine these Grand Challenges, including the areas of seismology ("Seismological Grand Challenges in Understanding Earth's Dynamic Systems"), mineral physics ("Unlocking the Building Blocks of the Planet"), EarthScope-related science ("Unlocking the Secrets of the North American Continent: An EarthScope Science Plan for 2010-2020"), and structural geology and tectonics (at the Structural Geology and Tectonics Forum held at Williams College in June, 2012). These research community efforts produced frameworks of the essential information for their fields with the aim of guiding future research. An integral part of this, however, is training the next generation of scientists, and using these Big Ideas as the basis for course structures and activities is a powerful way to make this happen. When activities, labs, and homeworks are drawn from relevant and cutting-edge research topics, students can find the material more fascinating and engaging, and can develop a better sense of the dynamic process of scientific discovery. Many creative ideas for incorporating the Grand Challenges of structural geology, tectonics, and geophysics in the classroom were developed at a Cutting Edge workshop on "Teaching Structural Geology, Geophysics, and Tectonics in the 21st Century" held at the University of Tennessee in July, 2012.

Facilitation of receptive and productive foreign vocabulary learning using the keyword method: the role of image quality.

PubMed

Beaton, Alan A; Gruneberg, Michael M; Hyde, Christopher; Shufflebottom, Alex; Sykes, Robert N

2005-07-01

Ellis and Beaton (1993a) reported that the keyword method of learning enhanced memory of foreign vocabulary items when receptive learning was measured. However, for productive learning, rote repetition was superior to the keyword method. The first two experiments reported here show that, in comparison with rote repetition, both receptive and productive learning can be enhanced by the keyword method, provided that the quality of the keyword images is adequate. In a third experiment using a subset of words from Ellis and Beaton (1993a), the finding they reported, that for productive learning rote repetition was superior to the keyword method, was reversed. The quality of keyword images will vary from study to study and any generalisation regarding the efficacy of the keyword method must take this into account.

Visualization and Analysis of Geology Word Vectors for Efficient Information Extraction

NASA Astrophysics Data System (ADS)

Floyd, J. S.

2016-12-01

When a scientist begins studying a new geographic region of the Earth, they frequently begin by gathering relevant scientific literature in order to understand what is known, for example, about the region's geologic setting, structure, stratigraphy, and tectonic and environmental history. Experienced scientists typically know what keywords to seek and understand that if a document contains one important keyword, then other words in the document may be important as well. Word relationships in a document give rise to what is known in linguistics as the context-dependent nature of meaning. For example, the meaning of the word `strike' in geology, as in the strike of a fault, is quite different from its popular meaning in baseball. In addition, word order, such as in the phrase `Cretaceous-Tertiary boundary,' often corresponds to the order of sequences in time or space. The context of words and the relevance of words to each other can be derived quantitatively by machine learning vector representations of words. Here we show the results of training a neural network to create word vectors from scientific research papers from selected rift basins and mid-ocean ridges: the Woodlark Basin of Papua New Guinea, the Hess Deep rift, and the Gulf of Mexico basin. The word vectors are statistically defined by surrounding words within a given window, limited by the length of each sentence. The word vectors are analyzed by their cosine distance to related words (e.g., `axial' and `magma'), classified by high dimensional clustering, and visualized by reducing the vector dimensions and plotting the vectors on a two- or three-dimensional graph. Similarity analysis of `Triassic' and `Cretaceous' returns `Jurassic' as the nearest word vector, suggesting that the model is capable of learning the geologic time scale. Similarity analysis of `basalt' and `minerals' automatically returns mineral names such as `chlorite', `plagioclase,' and `olivine.' Word vector analysis and visualization allow one to extract information from hundreds of papers or more and find relationships in less time than it would take to read all of the papers. As machine learning tools become more commonly available, more and more scientists will be able to use and refine these tools for their individual needs.

[Quality of health information about epilepsy on the Internet: Evaluation of French websites].

PubMed

Auvin, S; Dupont, S

2013-03-01

The Internet is now the single largest source of health information and is used by many patients who are affected by epilepsy and their families. To assess the quality of information provided by French website on the different forms of epilepsy and their treatment, we used search engines (French pages from Bing, Google and Yahoo) to look for information using the French equivalent of three keywords epilepsy (Épilepsie); epilepsy treatment (Épilepsie traitement) and seizure (Convulsions). The websites were evaluated for content quality by using an adaptation of the validated DISCERN rating instrument. Each website was evaluated by three investigators (a naive observer, a pediatric neurologist and a neurologist). Most of the information on epilepsy and its treatment were from community websites. We found six French websites which were scored higher than half of the maximal value of our scoring system (≥27.5/55): www.passeportsante.net; fr.wikipedia.org; www.fondation-epilepsie.fr; www.epilepsie-france.fr; www.doctissimo.fr; www.caducee.net. This study provides a list of French websites that have been evaluated for the quality of their information. We did not observe any correlation between the quality of the information and priority on search engine listings. Websites sponsored by patients associations and by institutions should update their content more frequently or work on their search engine indexation to appear higher on search engine listings. Copyright © 2012. Published by Elsevier Masson SAS.

Research pilot Mark Pestana

NASA Image and Video Library

2001-04-16

Mark Pestana is a research pilot and project manager at the NASA Dryden Flight Research Center, Edwards, Calif. He is a pilot for the Beech B200 King Air, the T-34C and the Predator B. He flies the F-18 Hornet as a co-pilot and flight test engineer. Pestana has accumulated more than 4,000 hours of military and civilian flight experience. He was also a flight engineer on the NASA DC-8 flying laboratory. Pestana was the project manager and pilot for the Hi–rate Wireless Airborne Network Demonstration flown on the NASA B200 research aircraft. He flew B200 research missions for the X-38 Space Integrated Inertial Navigation Global Positioning System experiment. Pestana also participated in several deployments of the DC-8, including Earth science expeditions ranging from hurricane research over the Caribbean Sea to ozone studies over the North Pole, atmospheric chemistry over the South Pacific, rain forest health in Central America, Rocky Mountain ice pack assessment, and volcanic and tectonic activity around the Pacific Rim. He came to Dryden as a DC-8 mission manager in June 1998 from NASA Johnson Space Center, Houston, where he served as the Earth and Space Science discipline manager for the International Space Station Program at Johnson. Pestana also served as a flight crew operations engineer in the Astronaut Office, developing the controls, displays, tools, crew accommodations and procedures for on-orbit assembly, test, and checkout of the International Space Station. He led the analysis and technical negotiations for modification of the Russian Soyuz spacecraft as an emergency crew return vehicle for space station crews. He joined the U.S. Air Force Reserve in 1991 and held various positions as a research and development engineer, intelligence analyst, and Delta II launch vehicle systems engineer. He retired from the U.S. Air Force Reserve with the rank of colonel in 2005. Prior to 1990, Pestana was on active duty with the U.S. Air Force as the director of mi

Parallel Extension Tectonics (PET): Early Cretaceous tectonic extension of the Eastern Eurasian continent

NASA Astrophysics Data System (ADS)

Liu, Junlai; Ji, Mo; Ni, Jinlong; Guan, Huimei; Shen, Liang

2017-04-01

The present study reports progress of our recent studies on the extensional structures in eastern North China craton and contiguous areas. We focus on characterizing and timing the formation/exhumation of the extensional structures, the Liaonan metamorphic core complex (mcc) and the Dayingzi basin from the Liaodong peninsula, the Queshan mcc, the Wulian mcc and the Zhucheng basin from the Jiaodong peninsula, and the Dashan magmatic dome within the Sulu orogenic belt. Magmatic rocks (either volcanic or plutonic) are ubiquitous in association with the tectonic extension (both syn- and post-kinematic). Evidence for crustal-mantle magma mixing are popular in many syn-kinematic intrusions. Geochemical analysis reveals that basaltic, andesitic to rhyolitic magmas were generated during the tectonic extension. Sr-Nd isotopes of the syn-kinematic magmatic rocks suggest that they were dominantly originated from ancient or juvenile crust partly with mantle signatures. Post-kinematic mafic intrusions with ages from ca. 121 Ma to Cenozoic, however, are of characteristic oceanic island basalts (OIB)-like trace element distribution patterns and relatively depleted radiogenic Sr-Nd isotope compositions. Integrated studies on the extensional structures, geochemical signatures of syn-kinematic magmatic rocks (mostly of granitic) and the tectono-magmatic relationships suggest that extension of the crust and the mantle lithosphere triggered the magmatisms from both the crust and the mantle. The Early Cretaceous tectono-magmatic evolution of the eastern Eurasian continent is governed by the PET in which the tectonic processes is subdivided into two stages, i.e. an early stage of tectonic extension, and a late stage of collapse of the extended lithosphere and transformation of lithospheric mantle. During the early stage, tectonic extension of the lithosphere led to detachment faulting in both the crust and mantle, resulted in the loss of some of the subcontinental roots, gave rise to the exhumation of the mccs, and triggered plutonic emplacement and volcanic eruptions of hybrid magmas. During the late stage, the nature of mantle lithosphere in North China was changed from the ancient SCLM to the juvenile SCLM. Extensional structures in eastern Eurasian continent provide a general architecture of the extensional tectonics of a rifted continent. Progressive extension resulted a sudden collaps of the crust (lithosphere) at ca. 130 to 120 Ma, associated with exhumation of mcc's and giant syn-kinematic magmatism, and post-kinematic magmatism. Parallel extension of both the crust and the mantle resulted in detachment faulting and magmatism, and also contributed to inhomogeneous thinning of the NCC lithosphere. Paleo-Pacific plate subduction and roll-back of the subducting oceanic plate contributed to the PET tectonic processes.

Automated semantic indexing of figure captions to improve radiology image retrieval.

PubMed

Kahn, Charles E; Rubin, Daniel L

2009-01-01

We explored automated concept-based indexing of unstructured figure captions to improve retrieval of images from radiology journals. The MetaMap Transfer program (MMTx) was used to map the text of 84,846 figure captions from 9,004 peer-reviewed, English-language articles to concepts in three controlled vocabularies from the UMLS Metathesaurus, version 2006AA. Sampling procedures were used to estimate the standard information-retrieval metrics of precision and recall, and to evaluate the degree to which concept-based retrieval improved image retrieval. Precision was estimated based on a sample of 250 concepts. Recall was estimated based on a sample of 40 concepts. The authors measured the impact of concept-based retrieval to improve upon keyword-based retrieval in a random sample of 10,000 search queries issued by users of a radiology image search engine. Estimated precision was 0.897 (95% confidence interval, 0.857-0.937). Estimated recall was 0.930 (95% confidence interval, 0.838-1.000). In 5,535 of 10,000 search queries (55%), concept-based retrieval found results not identified by simple keyword matching; in 2,086 searches (21%), more than 75% of the results were found by concept-based search alone. Concept-based indexing of radiology journal figure captions achieved very high precision and recall, and significantly improved image retrieval.

Radio Frequency Identification (RFID) technology and patient safety

PubMed Central

Ajami, Sima; Rajabzadeh, Ahmad

2013-01-01

Background: Radio frequency identification (RFID) systems have been successfully applied in areas of manufacturing, supply chain, agriculture, transportation, healthcare, and services to name a few. However, the different advantages and disadvantages expressed in various studies of the challenges facing the technology of the use of the RFID technology have been met with skepticism by managers of healthcare organizations. The aim of this study was to express and display the role of RFID technology in improving patient safety and increasing the impact of it in healthcare. Materials and Methods: This study was non-systematical review, which the literature search was conducted with the help of libraries, books, conference proceedings, PubMed databases and also search engines available at Google, Google scholar in which published between 2004 and 2013 during Febuary 2013. We employed the following keywords and their combinations; RFID, healthcare, patient safety, medical errors, and medication errors in the searching areas of title, keywords, abstract, and full text. Results: The preliminary search resulted in 68 articles. After a careful analysis of the content of each paper, a total of 33 papers was selected based on their relevancy. Conclusion: We should integrate RFID with hospital information systems (HIS) and electronic health records (EHRs) and support it by clinical decision support systems (CDSS), it facilitates processes and reduce medical, medication and diagnosis errors. PMID:24381626

Radio Frequency Identification (RFID) technology and patient safety.

PubMed

Ajami, Sima; Rajabzadeh, Ahmad

2013-09-01

Radio frequency identification (RFID) systems have been successfully applied in areas of manufacturing, supply chain, agriculture, transportation, healthcare, and services to name a few. However, the different advantages and disadvantages expressed in various studies of the challenges facing the technology of the use of the RFID technology have been met with skepticism by managers of healthcare organizations. The aim of this study was to express and display the role of RFID technology in improving patient safety and increasing the impact of it in healthcare. This study was non-systematical review, which the literature search was conducted with the help of libraries, books, conference proceedings, PubMed databases and also search engines available at Google, Google scholar in which published between 2004 and 2013 during Febuary 2013. We employed the following keywords and their combinations; RFID, healthcare, patient safety, medical errors, and medication errors in the searching areas of title, keywords, abstract, and full text. The preliminary search resulted in 68 articles. After a careful analysis of the content of each paper, a total of 33 papers was selected based on their relevancy. We should integrate RFID with hospital information systems (HIS) and electronic health records (EHRs) and support it by clinical decision support systems (CDSS), it facilitates processes and reduce medical, medication and diagnosis errors.

Information about epilepsy on the internet: An exploratory study of Arabic websites.

PubMed

Alkhateeb, Jamal M; Alhadidi, Muna S

2018-01-01

The aim of this study was to explore information about epilepsy found on Arabic websites. The researchers collected information from the internet between November 2016 and January 2017. Information was obtained using Google and Yahoo search engines. Keywords used were the Arabic equivalent of the following two keywords: epilepsy (Al-saraa) and convulsion (Tashanoj). A total of 144 web pages addressing epilepsy in Arabic were reviewed. The majority of web pages were websites of medical institutions and general health websites, followed by informational and educational websites, others, blogs and websites of individuals, and news and media sites. Topics most commonly addressed were medical treatments for epilepsy (50% of all pages) followed by epilepsy definition (41%) and epilepsy etiology (34.7%). The results also revealed that the vast majority of web pages did not mention the source of information. Many web pages also did not provide author information. Only a small proportion of the web pages provided adequate information. Relatively few web pages provided inaccurate information or made sweeping generalizations. As a result, it is concluded that the findings of the present study suggest that development of more credible Arabic websites on epilepsy is needed. These websites need to go beyond basic information, offering more evidence-based and updated information about epilepsy. Copyright © 2017 Elsevier Inc. All rights reserved.

Evolutionary features of academic articles co-keyword network and keywords co-occurrence network: Based on two-mode affiliation network

NASA Astrophysics Data System (ADS)

Li, Huajiao; An, Haizhong; Wang, Yue; Huang, Jiachen; Gao, Xiangyun

2016-05-01

Keeping abreast of trends in the articles and rapidly grasping a body of article's key points and relationship from a holistic perspective is a new challenge in both literature research and text mining. As the important component, keywords can present the core idea of the academic article. Usually, articles on a single theme or area could share one or some same keywords, and we can analyze topological features and evolution of the articles co-keyword networks and keywords co-occurrence networks to realize the in-depth analysis of the articles. This paper seeks to integrate statistics, text mining, complex networks and visualization to analyze all of the academic articles on one given theme, complex network(s). All 5944 ;complex networks; articles that were published between 1990 and 2013 and are available on the Web of Science are extracted. Based on the two-mode affiliation network theory, a new frontier of complex networks, we constructed two different networks, one taking the articles as nodes, the co-keyword relationships as edges and the quantity of co-keywords as the weight to construct articles co-keyword network, and another taking the articles' keywords as nodes, the co-occurrence relationships as edges and the quantity of simultaneous co-occurrences as the weight to construct keyword co-occurrence network. An integrated method for analyzing the topological features and evolution of the articles co-keyword network and keywords co-occurrence networks is proposed, and we also defined a new function to measure the innovation coefficient of the articles in annual level. This paper provides a useful tool and process for successfully achieving in-depth analysis and rapid understanding of the trends and relationships of articles in a holistic perspective.

Challenges to Progress in Studies of Climate-Tectonic-Erosion Interactions

NASA Astrophysics Data System (ADS)

Burbank, D. W.

2016-12-01

Attempts to unravel the relative importance of climate and tectonics in modulating topography and erosion should compare relevant data sets at comparable temporal and spatial scales. Given that such data are uncommonly available, how can we compare diverse data sets in a robust fashion? Many erosion-rate studies rely on detrital cosmogenic nuclides. What time scales can such data address, and what landscape conditions do they require to provide accurate representations of long-term erosion rates? To what extent do large-scale, but infrequent erosional events impact long-term rates? Commonly, long-term erosion rates are deduced from thermochronologic data. What types of data are needed to test for consistency of rates across a given interval or change in rates through time? Similarly, spatial and temporal variability in precipitation or tectonics requires averaging across appropriate scales. How are such data obtained in deforming mountain belts, and how do we assess their reliability? This study describes the character and temporal duration of key variables that are needed to examine climate-tectonic-erosion interactions, explores the strengths and weaknesses of several study areas, and suggests the types of data requirements that will underpin enlightening "tests" of hypotheses related to the mutual impacts of climate, tectonics, and erosion.

Lateral variations in geologic structure and tectonic setting from remote sensing data

NASA Astrophysics Data System (ADS)

Alexander, S. S.

1983-05-01

The principal objective of this study was: (1) to assess the usefulness of remote sensing digital imagery, principally LANDSAT multispectral scanning (MSS) data, for inferring lateral variations in geologic structure and tectonic setting; and (2) to determine the extent to which these inferred variations correlate with observed variations in seismic excitation from underground nuclear explosion test sites in the Soviet Union. Soviet, French and U.S. test sites have been investigated to compare their geologic and tectonic responses as seen by LANDSAT. The characteristics of "granite' intrusive bodies exposed at Semipalatinsk (Degelen), North Africa (Hoggar), NTS (Climax stock), and an analog site in Maine (Mt. Katahdin), have been studied in detail. The tectonic stress field inferred from the tectonic release portion of seismic signatures of explosions in these three areas is compared with local and regional fracture patterns discernable from imagery. The usefulness of satellite synthetic aperture radar (SAR) to determine geologic conditions and delineate fault (fracture) patterns is demonstrated by the analysis of SEASAT data for an area in the eastern United States. Algorithms to enhance structural boundaries and to use textures to identify rock types were developed and applied to several test sites.

Probabilistic landslide susceptibility mapping in the Lai Chau province of Vietnam: focus on the relationship between tectonic fractures and landslides

NASA Astrophysics Data System (ADS)

Lee, Saro; Dan, Nguyen Tu

2005-09-01

This study evaluates the susceptibility of landslides in the Lai Chau province of Vietnam using Geographic Information System (GIS) and remote sensing data to focus on the relationship between tectonic fractures and landslides. Landslide locations were identified from aerial photographs and field surveys. Topographic, geological data and satellite images were collected, processed, and constructed into a spatial database using GIS data and image-processing techniques. A scheme of the tectonic fracturing of crust in the Lai Chau region was established. Lai Chau was identified as a region with many crustal fractures, where the grade of tectonic fracture is closely related to landslide occurrence. The influencing factors of landslide occurrence were: distance from a tectonic fracture, slope, aspect, curvature, soil, and vegetative land cover. Landslide prone areas were analyzed and mapped using the landslide occurrence factors employing the probability-frequency ratio model. The results of the analysis were verified using landslide location data and showed 83.47% prediction accuracy. That emphasized a strong relationship between the susceptibility map and the existing landslide location data. The results of this study can form a basis stable development and land use planning for the region.

Diversity dynamics of Miocene mammals in relation to the history of tectonism and climate

PubMed Central

Finarelli, John A.; Badgley, Catherine

2010-01-01

Continental biodiversity gradients result not only from ecological processes, but also from evolutionary and geohistorical processes involving biotic turnover in landscape and climatic history over millions of years. Here, we investigate the evolutionary and historical contributions to the gradient of increasing species richness with topographic complexity. We analysed a dataset of 418 fossil rodent species from western North America spanning 25 to 5 Ma. We compared diversification histories between tectonically active (Intermontane West) and quiescent (Great Plains) regions. Although diversification histories differed between the two regions, species richness, origination rate and extinction rate per million years were not systematically different over the 20 Myr interval. In the tectonically active region, the greatest increase in originations coincided with a Middle Miocene episode of intensified tectonic activity and global warming. During subsequent global cooling, species richness declined in the montane region and increased on the Great Plains. These results suggest that interactions between tectonic activity and climate change stimulate diversification in mammals. The elevational diversity gradient characteristic of modern mammalian faunas was not a persistent feature over geologic time. Rather, the Miocene rodent record suggests that the elevational diversity gradient is a transient feature arising during particular episodes of Earth's history. PMID:20427339

Understanding Magnetic Anomalies and Their Significance.

ERIC Educational Resources Information Center

Shea, James H.

1988-01-01

Describes a laboratory exercise testing the Vine-Matthews-Morley hypothesis of plate tectonics. Includes 14 questions with explanations using graphs and charts. Provides a historical account of the current plate tectonic and magnetic anomaly theory. (MVL)

Collapse Features

NASA Image and Video Library

2010-09-15

The depressions in this image from NASA Mars Odyssey likely formed due to both volcanic and tectonic forces. Tectonic forces likely account for some of the depressions, while collapse into lava tubes and lava flow erosion account for the remainder.

The importance of the keyword-generation method in keyword mnemonics.

PubMed

Campos, Alfredo; Amor, Angeles; González, María Angeles

2004-01-01

Keyword mnemonics is under certain conditions an effective approach for learning foreign-language vocabulary. It appears to be effective for words with high image vividness but not for words with low image vividness. In this study, two experiments were performed to assess the efficacy of a new keyword-generation procedure (peer generation). In Experiment 1, a sample of 363 high-school students was randomly into four groups. The subjects were required to learn L1 equivalents of a list of 16 Latin words (8 with high image vividness, 8 with low image vividness), using a) the rote method, or the keyword method with b) keywords and images generated and supplied by the experimenter, c) keywords and images generated by themselves, or d) keywords and images previously generated by peers (i.e., subjects with similar sociodemographic characteristics). Recall was tested immediately and one week later. For high-vivideness words, recall was significantly better in the keyword groups than the rote method group. For low-vividness words, learning method had no significant effect. Experiment 2 was basically identical, except that the word lists comprised 32 words (16 high-vividness, 16 low-vividness). In this experiment, the peer-generated-keyword group showed significantly better recall of high-vividness words than the rote method groups and the subject generated keyword group; again, however, learning method had no significant effect on recall of low-vividness words.

A novel word spotting method based on recurrent neural networks.

PubMed

Frinken, Volkmar; Fischer, Andreas; Manmatha, R; Bunke, Horst

2012-02-01

Keyword spotting refers to the process of retrieving all instances of a given keyword from a document. In the present paper, a novel keyword spotting method for handwritten documents is described. It is derived from a neural network-based system for unconstrained handwriting recognition. As such it performs template-free spotting, i.e., it is not necessary for a keyword to appear in the training set. The keyword spotting is done using a modification of the CTC Token Passing algorithm in conjunction with a recurrent neural network. We demonstrate that the proposed systems outperform not only a classical dynamic time warping-based approach but also a modern keyword spotting system, based on hidden Markov models. Furthermore, we analyze the performance of the underlying neural networks when using them in a recognition task followed by keyword spotting on the produced transcription. We point out the advantages of keyword spotting when compared to classic text line recognition.

Tectonic evolution of Western Ishtar Terra, Venus

NASA Astrophysics Data System (ADS)

Marinangeli, Lucia

1997-03-01

A detailed geological mapping based on Magellan data has been done in Western Ishtar Terra from 300-330 deg W to 65-75 deg N. The area studied comprises three main phisiografic provinces, Atropos Tessera, Akna Montes and North-Western Lakshmi Planum. The purposes of this study are (1) to recognize the tectonism of this area and investigate its type, direction, intensity, distribution and age relationships, (2) to define the link between the formation of the Akna mountain belt and the tectonic deformation in adjacent Tessera and Lakshmi Planum.

Tectonic control of Middle Devonian reef building in the Mechra ben Abbou (northern Rehamna, Morocco)Contrôle tectonique de l'édification des récifs Dévonien moyen de Mechra ben Abbou (Rehamna, Maroc)

NASA Astrophysics Data System (ADS)

El Kamel, Fouad; El Hassani, Ahmed; Mohsine, Assia; Remmal, Toufik

2000-01-01

In the carbonated platform of Upper Emsian to Givetian age, the reef edification is previous to, and contemporaneous with, a tilted block tectonic that has favoured the bioconstruction in its upper part. The tectonic expression is illustrated by several instability marks, such as tension faults, progressive unconformity and the resulting landslide, observed in both the reef development zone and the external platform.

A global tectonic activity map with orbital photographic supplement

NASA Technical Reports Server (NTRS)

Lowman, P. D., Jr.

1981-01-01

A three part map showing equatorial and polar regions was compiled showing tectonic and volcanic activity of the past one million years, including the present. Features shown include actively spreading ridges, spreading rates, major active faults, subduction zones, well defined plates, and volcanic areas active within the past one million years. Activity within this period was inferred from seismicity (instrumental and historic), physiography, and published literature. The tectonic activity map was used for planning global geodetic programs of satellite laser ranging and very long base line interferometry and for geologic education.

Gravity anomalies, plate tectonics and the lateral growth of Precambrian North America

NASA Technical Reports Server (NTRS)

Thomas, M. D.; Grieve, R. A. F.; Sharpton, V. L.

1988-01-01

The widespread gravity coverage of North America provides a picture of the gross structural fabric of the continent via the trends of gravity anomalies. The structural picture so obtained reveals a mosaic of gravity trend domains, many of which correlate closely with structural provinces and orogenic terranes. The gravity trend map, interpreted in the light of plate-tectonic theory, thus provides a new perspective for examining the mode of assembly and growth of North America. Suture zones, palaeosubduction directions, and perhaps, contrasting tectonic histories may be identified using gravity patterns.

Developing Regionalized Models of Lithospheric Thickness and Velocity Structure Across Eurasia and the Middle East from Jointly Inverting P-Wave and S-Wave Receiver Functions with Rayleigh Wave Group and Phase Velocities

DTIC Science & Technology

2010-09-01

lithospheric velocity structure for a wide variety of tectonic regions throughout Eurasia and the Middle East. We expect the regionalized models will improve...constructed by combining the 1D joint inversion models within each tectonic region and validated through regional waveform modeling. The velocity models thus...important differences in lithospheric structure between the cratonic regions of Eastern Europe and the tectonic regions of Western Europe and the

Analysis of the Tectonic Lineaments in the Ganiki Planitia (V14) Quadrangle, Venus

NASA Technical Reports Server (NTRS)

Venechuk, E. M.; Hurwitz, D. M.; Drury, D. E.; Long, S. M.; Grosfils, E. B.

2005-01-01

The Ganiki Planitia quadrangle, located between the Atla Regio highland to the south and the Atalanta Planitia lowland to the north, is deformed by many tectonic lineaments which have been mapped previously but have not yet been assessed in detail. As a result, neither the characteristics of these lineaments nor their relationship to material unit stratigraphy is well constrained. In this study we analyze the orientation of extensional and compressional lineaments in all non-tessera areas in order to begin characterizing the dominant tectonic stresses that have affected the region.

Text analysis of MEDLINE for discovering functional relationships among genes: evaluation of keyword extraction weighting schemes.

PubMed

Liu, Ying; Navathe, Shamkant B; Pivoshenko, Alex; Dasigi, Venu G; Dingledine, Ray; Ciliax, Brian J

2006-01-01

One of the key challenges of microarray studies is to derive biological insights from the gene-expression patterns. Clustering genes by functional keyword association can provide direct information about the functional links among genes. However, the quality of the keyword lists significantly affects the clustering results. We compared two keyword weighting schemes: normalised z-score and term frequency-inverse document frequency (TFIDF). Two gene sets were tested to evaluate the effectiveness of the weighting schemes for keyword extraction for gene clustering. Using established measures of cluster quality, the results produced from TFIDF-weighted keywords outperformed those produced from normalised z-score weighted keywords. The optimised algorithms should be useful for partitioning genes from microarray lists into functionally discrete clusters.

The alternative concept of global tectonics

NASA Astrophysics Data System (ADS)

Anokhin, Vladimir; Kholmyansky, Mikhael

2016-04-01

The existing plate tectonic paradigm becomes more questionable in relation to the new facts of the Earth. The most complete to date criticism of plate tectonics provisions contained in the article (Pratt, 2000). Authors can recall a few facts that contradict the idea of long-range movement of plates: - The absence of convection cells in the mantle, detected by seismic tomography; - The presence of long-lived deep regmatic network in the crust, not distorted by the movement of plates; - The inability of linking the global geometry of the of mutual long-distance movement of plates. All this gives reason to believe that correct, or at least a satisfactory concept of global tectonics are not exist now. After overcoming the usual inertia of thinking the plate paradigm in the foreseeable future will replace by different concept, more relevant as the observable facts of the Earth and the well-known physical laws. The authors suggest that currently accumulated sufficient volume of facts and theoretical ideas for the synthesis of a new general hypothesis of the structure and dynamics of the Earth. Analysis of the existing tectonic theory suggests that most of their provisions are mutually compatible. Obviously, plume tectonics perfectly compatible with any of classical models. It contradicts the only plate tectonics (movement of hot spots in principle not linked either with each other or with the general picture of the plate movements, the presence of mantle convection and mantle streams are mutually exclusive, and so on). The probable transfer of the heated material down up within the Earth may occur in various forms, the simplest of which (and, consequently, the most probable) are presented plumes. The existence in the mantle numerous large volumes of decompressed substances (detected seismic tomography), can be correlated with the bodies of plumes at different stages of uplift. Plumes who raise to the bottom of the lithosphere, to spread out to the sides and form a set of lenses partially molten mantle material - asthenolithes previously mistaken for ubiquitous asthenosphere. Interaction between a plumes and their impact on the crust gives rise to all of the observed tectonic processes, including geosynclinal. This scheme is well complemented by some of the elements of plate tectonics, such as the separation of the crust for large plates across the present seismic belts, regional tension along the "divergence" borders, regional compression and collisions along the "convergence" borders. It is necessary to reject the dogmatic, contrary to the facts and unnecessary assumptions about the far moving plates, terraines, "hidden" boundaries, etc. The proposed scheme is contained not so much a new idea as a synthesis of already known ideas. The authors believe that in this way it is possible to construct a general geotectonic concept that would match the best of our knowledge in the earth sciences. Reference: David Pratt, Plate Tectonics: A Paradigm Under Threat - Journal of Scientific Exploration, vol. 14, no. 3, pp. 307-352, 2000.

The Lord Howe Rise continental ribbon: a fragment of eastern Gondwana that reveals the drivers of continental rifting and plate tectonics

NASA Astrophysics Data System (ADS)

Saito, S.; Hackney, R. I.; Bryan, S. E.; Kimura, J. I.; Müller, D.; Arculus, R. J.; Mortimer, N. N.; Collot, J.; Tamura, Y.; Yamada, Y.

2016-12-01

Plate tectonics and resulting changes in crustal architecture profoundly influence global climate, oceanic circulation, and the origin, distribution and sustainability of life. Ribbons of continental crust rifted from continental margins are one product of plate tectonics that can influence the Earth system. Yet we have been unable to fully resolve the tectonic setting and evolution of huge, thinned, submerged, and relatively inaccessible continental ribbons like the Lord Howe Rise (LHR), which formed during Cretaceous fragmentation of eastern Gondwana. Thinned continental ribbons like the LHR are not easily explained or predicted by plate-tectonic theory. However, because Cretaceous rift basins on the LHR preserve the stratigraphy of an un-accreted and intact continental ribbon, they can help to determine whether plate motion is self-organised—passively driven by the pull of negatively-buoyant subducting slabs—or actively driven by convective flow in the mantle. In a self-organising scenario, the LHR formed in response to ocean-ward retreat of the long-lived eastern Gondwana subduction zone and linked upper-plate extension. In the mantle-driven scenario, the LHR resulted from rifting near the eastern edge of Gondwana that was triggered by processes linked to emplacement of a silicic Large Igneous Province. These scenarios can be distinguished using the ribbon's extensional history and the composition and tectonic affinity of igneous rocks within rift basins. However, current knowledge of LHR rift basins is based on widely-distributed marine and satellite geophysical data, limited dredge samples, and sparse shallow drilling (<600 m below-seafloor). This limits our ability to understand the evolution of extended continental ribbons, but a recent deep crustal seismic survey across the LHR and a proposed IODP deep stratigraphic well through a LHR rift basin provide new opportunities to explore the drivers behind rifting, continental ribboning and plate tectonics.