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Sample records for earthquake related phenomena

  1. Luminous phenomena and electromagnetic VHF wave emission originated from earthquake-related radon exhalation

    NASA Astrophysics Data System (ADS)

    Seki, A.; Tobo, I.; Omori, Y.; Muto, J.; Nagahama, H.

    2013-12-01

    Anomalous luminous phenomena and electromagnetic wave emission before or during earthquakes have been reported (e.g., the 1965 Matsushiro earthquake swarm). However, their mechanism is still unsolved, in spite of many models for these phenomena. Here, we propose a new model about luminous phenomena and electromagnetic wave emission during earthquake by focusing on atmospheric radon (Rn-222) and its daughter nuclides (Po-218 and Po-214). Rn-222, Po-218 and Po-214 are alpha emitters, and these alpha particles ionize atmospheric molecules. A light emission phenomenon, called 'the air luminescence', is caused by de-excitation of the ionized molecules of atmospheric nitrogen due to electron impact ionization from alpha particles. The de-excitation is from the second positive system of neutral nitrogen molecules and the first negative system of nitrogen molecule ion. Wavelengths of lights by these transitions include the visible light wavelength. So based on this mechanism, we proposed a new luminous phenomenon model before or during earthquake: 1. The concentration of atmospheric radon and its daughter nuclides increase anomalously before or during earthquakes, 2. Nitrogen molecules and their ions are excited by alpha particles emitted from Rn-222, Po-218 and Po-214, and air luminescence is generated by their de-excitation. Similarly, electromagnetic VHF wave emission can be explained by ionizing effect of radon and its daughter nuclides. Boyarchuk et al. (2005) proposed a model that electromagnetic VHF wave emission is originated when excited state of neutral clusters changes. Radon gas ionizes atmosphere and forms positively and negatively charged heavy particles. The process of ion hydration in ordinary air can be determined by the formation of complex chemically active structures of the various types of ion radicals. As a result of the association of such hydration radical ions, a neutral cluster, which is dipole quasi-molecules, is formed. A neutral cluster

  2. Structural variation along the southwestern Nankai seismogenic zone related to various earthquake phenomena

    NASA Astrophysics Data System (ADS)

    Nakanishi, A.; Shimomura, N.; Kodaira, S.; Obana, K.; Takahashi, T.; Yamamoto, Y.; Sato, T.; Kashiwase, K.; Fujimori, H.; Kaneda, Y.; Mochizuki, K.; Kato, A.; Iidaka, T.; Kurashimo, E.; Shinohara, M.; Takeda, T.; Shiomi, K.

    2011-12-01

    In the Nankai Trough subduction seismogenic zone, the Nankai and Tonankai earthquakes had often occurred simultaneously, and caused a great event. In order to reduce a great deal of damage to coastal area from both strong ground motion and tsunami generation, it is necessary to understand rupture synchronization and segmentation of the Nankai megathrust earthquake. For a precise estimate of the rupture area of the Nankai megathrust event, it is important to know the geometry of the subducting Philippine Sea plate and deep subduction structure along the Nankai Trough. To obtain the deep subduction structure of the coseismic rupture area of the Nankai earthquake in 1946 off Shikoku area, the large-scale high-resolution wide-angle seismic study was conducted in 2009 and 2010. In this study, 201 and 200 ocean bottom seismographs were deployed off the Shikoku Island and the Kii channel respectively. A tuned airgun system (7800 cu. in.) shot every 200m along 13 profiles. Airgun shots were also recorded along an onshore seismic profile (prepared by ERI, univ. of Tokyo and NIED) prolonged from the offshore profile off the Kii Peninsula. Long-term observation was conducted for ~9 months by 21 OBSs off the Shikoku area and 20 OBSs off the Kii channel.This research is part of 'Research concerning Interaction Between the Tokai, Tonankai and Nankai Earthquakes' funded by Ministry of Education, Culture, Sports, Science and Technology, Japan. Structural images of the overriding plate indicate the old accreted sediments (the Cretaceous-Tertiary accretionary prism) with the velocity greater than 6km/s extend seaward from off the Shikoku to the Hyuga-nada. Moreover, the young accreted sediments become relatively thinner eastward from off the cape Ashizuri to Muroto. These structural variations might be related to the different rupture pattern of the Nankai event. Structural image of the deep low frequency earthquakes and tremors is shown by using the airgun shots recorded at onshore

  3. Earthquake prediction with electromagnetic phenomena

    SciT

    Hayakawa, Masashi, E-mail: hayakawa@hi-seismo-em.jp; Advanced Wireless & Communications Research Center, UEC, Chofu Tokyo; Earthquake Analysis Laboratory, Information Systems Inc., 4-8-15, Minami-aoyama, Minato-ku, Tokyo, 107-0062

    Short-term earthquake (EQ) prediction is defined as prospective prediction with the time scale of about one week, which is considered to be one of the most important and urgent topics for the human beings. If this short-term prediction is realized, casualty will be drastically reduced. Unlike the conventional seismic measurement, we proposed the use of electromagnetic phenomena as precursors to EQs in the prediction, and an extensive amount of progress has been achieved in the field of seismo-electromagnetics during the last two decades. This paper deals with the review on this short-term EQ prediction, including the impossibility myth of EQsmore » prediction by seismometers, the reason why we are interested in electromagnetics, the history of seismo-electromagnetics, the ionospheric perturbation as the most promising candidate of EQ prediction, then the future of EQ predictology from two standpoints of a practical science and a pure science, and finally a brief summary.« less

  4. Gas and Dust Phenomena of Mega-earthquakes and the Cause

    NASA Astrophysics Data System (ADS)

    Yue, Z.

    2013-12-01

    A mega-earthquake suddenly releases a large to extremely large amount of kinetic energy within a few tens to two hundreds seconds and over ten to hundreds kilometer distances in the Earth's crust and on ground surface. It also generates seismic waves that can be received globally and co-seismic ground damages such co-seismic ruptures and landslides. However, such vast, dramatic and devastating kinetic actions in the Earth's crustal rocks and on the ground soils cannot be known or predicted by people at few weeks, days, hours, or minutes before they are happening. Although seismologists can develop and use seismometers to report the locations and magnitudes of earthquakes within minutes of their occurrence, they cannot predict earthquakes at present. Therefore, damage earthquakes have caused and would continue to cause huge disasters, fatalities and injuries to our human beings. This problem may indicate that it is necessary to re-examine the cause of mega-earthquakes in addition to the conventional cause of active fault elastic rebounding. In the last ten years, many mega-earthquakes occurred in China and around the Pacific Ocean and caused many casualties to human beings and devastating disasters to environments. The author will give a brief review on the impacts of the mega-earthquakes happened in recent years. He will then present many gas and dust related phenomena associated with the sudden occurrences of these mega earthquakes. They include the 2001 Kunlunshan Earthquake M8.1, 2008 Wenchuan Earthquake M8.0 and the 2010 Yushu Earthquake M7.1 in China, the 2010 Haiti Earthquake M7.0, the 2010 Mexicali Earthquake M7.2, the 2010 Chile Earthquake M8.8, the 2011 Christchurch earthquake M6.3 and the 2011 Japan Earthquake M9.0 around the Pacific Ocean. He will discuss the cause of these gas and dust related phenomena. He will use these phenomena and their common cause to show that the earthquakes were caused the rapid migration and expansion of highly compressed and

  5. Earthquake Scaling Relations

    NASA Astrophysics Data System (ADS)

    Jordan, T. H.; Boettcher, M.; Richardson, E.

    2002-12-01

    Using scaling relations to understand nonlinear geosystems has been an enduring theme of Don Turcotte's research. In particular, his studies of scaling in active fault systems have led to a series of insights about the underlying physics of earthquakes. This presentation will review some recent progress in developing scaling relations for several key aspects of earthquake behavior, including the inner and outer scales of dynamic fault rupture and the energetics of the rupture process. The proximate observations of mining-induced, friction-controlled events obtained from in-mine seismic networks have revealed a lower seismicity cutoff at a seismic moment Mmin near 109 Nm and a corresponding upper frequency cutoff near 200 Hz, which we interpret in terms of a critical slip distance for frictional drop of about 10-4 m. Above this cutoff, the apparent stress scales as M1/6 up to magnitudes of 4-5, consistent with other near-source studies in this magnitude range (see special session S07, this meeting). Such a relationship suggests a damage model in which apparent fracture energy scales with the stress intensity factor at the crack tip. Under the assumption of constant stress drop, this model implies an increase in rupture velocity with seismic moment, which successfully predicts the observed variation in corner frequency and maximum particle velocity. Global observations of oceanic transform faults (OTFs) allow us to investigate a situation where the outer scale of earthquake size may be controlled by dynamics (as opposed to geologic heterogeneity). The seismicity data imply that the effective area for OTF moment release, AE, depends on the thermal state of the fault but is otherwise independent of fault's average slip rate; i.e., AE ~ AT, where AT is the area above a reference isotherm. The data are consistent with β = 1/2 below an upper cutoff moment Mmax that increases with AT and yield the interesting scaling relation Amax ~ AT1/2. Taken together, the OTF

  6. An integrated perspective of the continuum between earthquakes and slow-slip phenomena

    Peng, Zhigang; Gomberg, Joan

    2010-01-01

    The discovery of slow-slip phenomena has revolutionized our understanding of how faults accommodate relative plate motions. Faults were previously thought to relieve stress either through continuous aseismic sliding, or as earthquakes resulting from instantaneous failure of locked faults. In contrast, slow-slip events proceed so slowly that slip is limited and only low-frequency (or no) seismic waves radiate. We find that slow-slip phenomena are not unique to the depths (tens of kilometres) of subduction zone plate interfaces. They occur on faults in many settings, at numerous scales and owing to various loading processes, including landslides and glaciers. Taken together, the observations indicate that slowly slipping fault surfaces relax most of the accrued stresses through aseismic slip. Aseismic motion can trigger more rapid slip elsewhere on the fault that is sufficiently fast to generate seismic waves. The resulting radiation has characteristics ranging from those indicative of slow but seismic slip, to those typical of earthquakes. The mode of seismic slip depends on the inherent characteristics of the fault, such as the frictional properties. Slow-slip events have previously been classified as a distinct mode of fault slip compared with that seen in earthquakes. We conclude that instead, slip modes span a continuum and are of common occurrence.

  7. Nonlinear phenomena in general relativity

    NASA Astrophysics Data System (ADS)

    Allahyari, Alireza; Firouzjaee, Javad T.; Mansouri, Reza

    2018-04-01

    The perturbation theory plays an important role in studying structure formation in cosmology and post-Newtonian physics, but not all phenomena can be described by the linear perturbation theory. Thus, it is necessary to study exact solutions or higher-order perturbations. Specifically, we study black hole (apparent) horizons and the cosmological event horizon formation in the perturbation theory. We emphasize that in the perturbative regime of the gravitational potential these horizons cannot form in the lower order. Studying the infinite plane metric, we show that, to capture the cosmological constant effect, we need at least a second-order expansion.

  8. Electromagnetic earthquake triggering phenomena: State-of-the-art research and future developments

    NASA Astrophysics Data System (ADS)

    Zeigarnik, Vladimir; Novikov, Victor

    2014-05-01

    of geoacoustic emission recorded in the wells at a distance of 7-12 km from the emitting dipole to the ERGU-600 pulses confirmed the effects of an influence of electromagnetic field on the deformation processes in the Earth crust and the real existence of electromagnetic triggering phenomena. For verification of results of field observations laboratory studies of behavior of rock samples under critical stress-strain state and external electric actions were carried out at the spring and lever presses, as well as at the stick-slip models simulated the seismic cycle (stress accumulation and discharge) in the seismogenic geological fault. Various possible mechanisms of weak electrical stimulation (electric current density 10-7-10-8 mA/cm2 at a depth of earthquake epicenters of 5 to10 km) of deformation processes in the Earth crust, including increased fluid pore pressure, electrokinetic phenomena, magnetostriction, electrical stimulation of fluid migration into the fault area are considered. However, the mechanism of electromagnetic earthquake triggering phenomena is still open. Based on the field observations of electromagnetic triggering of weak seismicity resulting in a partial safe release of stresses in the Earth crust a possibility of control of seismic process is considered for risk reduction of catastrophic earthquakes. The results obtained from field and laboratory experiments on electromagnetic initiation of seismic events allow to consider a problem of lithosphere-ionosphere relations from another point of view. Keeping in mind that the current density generated in the Earth crust by artificial electric source is comparable with the density of telluric currents induced during severe ionospheric disturbances (e.g., magnetic storms) it may be possible under certain favorable conditions in lithosphere to initiate earthquakes by electromagnetic disturbances in ionosphere. A possibility of application of these triggering phenomena for short-term earthquake

  9. Slow-Slip Phenomena Represented by the One-Dimensional Burridge-Knopoff Model of Earthquakes

    NASA Astrophysics Data System (ADS)

    Kawamura, Hikaru; Yamamoto, Maho; Ueda, Yushi

    2018-05-01

    Slow-slip phenomena, including afterslips and silent earthquakes, are studied using a one-dimensional Burridge-Knopoff model that obeys the rate-and-state dependent friction law. By varying only a few model parameters, this simple model allows reproducing a variety of seismic slips within a single framework, including main shocks, precursory nucleation processes, afterslips, and silent earthquakes.

  10. Discrete Scaling in Earthquake Precursory Phenomena: Evidence in the Kobe Earthquake, Japan

    NASA Astrophysics Data System (ADS)

    Johansen, Anders; Sornette, Didier; Wakita, Hiroshi; Tsunogai, Urumu; Newman, William I.; Saleur, Hubert

    1996-10-01

    We analyze the ion concentration of groundwater issuing from deep wells located near the epicenter of the recent earthquake of magnitude 6.9 near Kobe, Japan, on January 17, 1995. These concentrations are well fitted by log-periodic modulations around a leading power law. The exponent (real and imaginary parts) is very close to those already found for the fits of precursory seismic activity for Loma Prieta and the Aleutian Islands. This brings further support for the general hypothesis that complex critical exponents are a general phenomenon in irreversible self-organizing systems and particularly in rupture and earthquake phenomena. Nous analysons les fluctuations de concentrations ioniques de l'eau issue de puits profonds situés à proximité de l'épicentre du récent tremblement de terre de magnitude 6.9 proche de Kobe au Japon, le 17 janvier 1995. Ces fluctuations sont bien reproduites par des modulations log-périodiques autour d'une loi de puissance. Les parties réelle et imaginaire de l'exposant sont très proches de celles trouvées précédemment pour les tremblements de terre de Loma Prieta et des Iles Aléoutiennes. Ces résultats renforcent l'hypothèse que des exposants critiques complexes sont une propriété générale des phénomènes de croissance irréversible, et en particulier des problèmes de rupture et des tremblements de terre.

  11. The Seminole Serpent Warrior At Miramar, FL, Shows Settlement Locations Enabled Environmental Monitoring Reminiscent Of the Four-corners Kokopelli-like EMF Phenomena, and Related to Earthquakes, Tornados and Hurricanes.

    NASA Astrophysics Data System (ADS)

    Balam Matagamon, Chan; Pawa Matagamon, Sagamo

    2004-03-01

    Certain Native Americans of the past seem to have correctly deduced that significant survival information for their tradition-respecting cultures resided in EMF-based phenomena that they were monitoring. This is based upon their myths and the place or cult-hero names they bequeathed us. The sites we have located in FL have been detectable by us visually, usually by faint blue light, or by the elicitation of pin-like prickings, by somewhat intense nervous-system response, by EMF interactions with aural electrochemical systems that can elicit tinitus, and other ways. In the northeast, Cautantowit served as a harbinger of Indian summer, and appears to be another alter ego of the EMF. The Miami, FL Tequesta site along the river clearly correlates with tornado, earthquake and hurricane locations. Sites like the Mohave Deserts giant man may have had similar significance.

  12. Period doubling and other nonlinear phenomena in volcanic earthquakes and tremor

    Julian, B.R.

    2000-01-01

    Evidence of subharmonic period-doubling cascades has recently been recognized in seismograms of volcanic tremor from several volcanoes. This phenomenon occurs only in nonlinear systems, and is the commonest route by which such systems change from periodic to chaotic behavior. It is predicted to occur in a model of volcanic tremor excitation by flow-induced vibration, and it might well also occur in other volcano-seismic source process. If the possibility of period doubling is not taken into account in interpreting spectra of tremor and long-period earthquakes, then low-frequency "sub-harmonic" oscillations may be mis-identified as normal modes of a linear acoustic resonator, leading to errors of an order of magnitude or more in inferred magma-body dimensions. This example illustrates the importance of nonlinear phenomena in attempts to understand volcano-seismic phenomena physically. Linear systems are fundamentally incapable of causing earthquakes or exciting tremor, so nonlinearity is essential to any theory of volcano-seismic phenomena. Nonlinear processes are in many respects qualitatively different from linear ones. A few of their characteristics that might be relevant in volcanoes include the possibility: (1) that damping might increase, rather than decrease, oscillation frequencies; and (2) that these frequencies might be functions of the amplitude of oscillation, so that temporal variations in spectral peak frequencies might not be manifestations of changes of conditions within the magmatic system.

  13. Near Space Tracking of the EM Phenomena Associated with the Main Earthquakes

    NASA Technical Reports Server (NTRS)

    Ouzounov, Dimitar; Taylor, Patrick; Bryant, Nevin; Pulinets, Sergey; Liu, Jann-Yenq; Yang, Kwang-Su

    2004-01-01

    Searching for electromagnetic (EM) phenomena originating in the Earth's crust prior to major earthquakes (M>5) are the object of this exploratory study. We present the idea of a possible relationship between: (1) electro-chemical and thermodynamic processes in the Earth's crust and (2) ionic enhancement of the atmosphere/ionosphere with tectonic stress and earthquake activity. The major source of these signals are proposed to originate from electromagnetic phenomenon which are responsible for these observed pre-seismic processes, such as, enhanced IR emission, also born as thermal anomalies, generation of long wave radiation, light emission caused by ground-to-air electric discharges, Total Electron Content (TEC) ionospheric anomalies and ionospheric plasma variations. The source of these data will include: (i) ionospheric plasma perturbations data from the recently launched DEMETER mission and currently available TEC/GPS network data; (ii) geomagnetic data from ORSTED and CHAMP; (iii) Thermal infra-red (TIR) transients mapped by the polar orbiting (NOAA/AVHRR, MODIS) and (iv) geosynchronous weather satellites measurements of GOES, METEOSAT. This approach requires continues observations and data collecting, in addition to both ground and space based monitoring over selected regions in order to investigate the various techniques for recording possible anomalies. During the space campaign emphasis will be on IR emission, obtained from TIR (thermal infrared) satellites, that records land/sea surface temperature anomalies and changes in the plasma and total electron content (TEC) of the ionosphere that occur over areas of potential earthquake activity.

  14. Causal mechanisms of seismo-EM phenomena during the 1965-1967 Matsushiro earthquake swarm.

    PubMed

    Enomoto, Yuji; Yamabe, Tsuneaki; Okumura, Nobuo

    2017-03-21

    The 1965-1967 Matsushiro earthquake swarm in central Japan exhibited two unique characteristics. The first was a hydro-mechanical crust rupture resulting from degassing, volume expansion of CO 2 /water, and a crack opening within the critically stressed crust under a strike-slip stress. The other was, despite the lower total seismic energy, the occurrence of complexed seismo-electromagnetic (seismo-EM) phenomena of the geomagnetic intensity increase, unusual earthquake lights (EQLs) and atmospheric electric field (AEF) variations. Although the basic rupture process of this swarm of earthquakes is reasonably understood in terms of hydro-mechanical crust rupture, the associated seismo-EM processes remain largely unexplained. Here, we describe a series of seismo-EM mechanisms involved in the hydro-mechanical rupture process, as observed by coupling the electric interaction of rock rupture with CO 2 gas and the dielectric-barrier discharge of the modelled fields in laboratory experiments. We found that CO 2 gases passing through the newly created fracture surface of the rock were electrified to generate pressure-impressed current/electric dipoles, which could induce a magnetic field following Biot-Savart's law, decrease the atmospheric electric field and generate dielectric-barrier discharge lightning affected by the coupling effect between the seismic and meteorological activities.

  15. Causal mechanisms of seismo-EM phenomena during the 1965–1967 Matsushiro earthquake swarm

    PubMed Central

    Enomoto, Yuji; Yamabe, Tsuneaki; Okumura, Nobuo

    2017-01-01

    The 1965–1967 Matsushiro earthquake swarm in central Japan exhibited two unique characteristics. The first was a hydro-mechanical crust rupture resulting from degassing, volume expansion of CO2/water, and a crack opening within the critically stressed crust under a strike-slip stress. The other was, despite the lower total seismic energy, the occurrence of complexed seismo-electromagnetic (seismo-EM) phenomena of the geomagnetic intensity increase, unusual earthquake lights (EQLs) and atmospheric electric field (AEF) variations. Although the basic rupture process of this swarm of earthquakes is reasonably understood in terms of hydro-mechanical crust rupture, the associated seismo-EM processes remain largely unexplained. Here, we describe a series of seismo-EM mechanisms involved in the hydro-mechanical rupture process, as observed by coupling the electric interaction of rock rupture with CO2 gas and the dielectric-barrier discharge of the modelled fields in laboratory experiments. We found that CO2 gases passing through the newly created fracture surface of the rock were electrified to generate pressure-impressed current/electric dipoles, which could induce a magnetic field following Biot-Savart’s law, decrease the atmospheric electric field and generate dielectric-barrier discharge lightning affected by the coupling effect between the seismic and meteorological activities. PMID:28322263

  16. Causal mechanisms of seismo-EM phenomena during the 1965-1967 Matsushiro earthquake swarm

    NASA Astrophysics Data System (ADS)

    Enomoto, Yuji; Yamabe, Tsuneaki; Okumura, Nobuo

    2017-03-01

    The 1965-1967 Matsushiro earthquake swarm in central Japan exhibited two unique characteristics. The first was a hydro-mechanical crust rupture resulting from degassing, volume expansion of CO2/water, and a crack opening within the critically stressed crust under a strike-slip stress. The other was, despite the lower total seismic energy, the occurrence of complexed seismo-electromagnetic (seismo-EM) phenomena of the geomagnetic intensity increase, unusual earthquake lights (EQLs) and atmospheric electric field (AEF) variations. Although the basic rupture process of this swarm of earthquakes is reasonably understood in terms of hydro-mechanical crust rupture, the associated seismo-EM processes remain largely unexplained. Here, we describe a series of seismo-EM mechanisms involved in the hydro-mechanical rupture process, as observed by coupling the electric interaction of rock rupture with CO2 gas and the dielectric-barrier discharge of the modelled fields in laboratory experiments. We found that CO2 gases passing through the newly created fracture surface of the rock were electrified to generate pressure-impressed current/electric dipoles, which could induce a magnetic field following Biot-Savart’s law, decrease the atmospheric electric field and generate dielectric-barrier discharge lightning affected by the coupling effect between the seismic and meteorological activities.

  17. The 1980 Irpinia-Basilicata earthquake: the environmental phenomena and the choices of reconstruction.

    NASA Astrophysics Data System (ADS)

    Porfido, Sabina; Alessio, Giuliana; Avallone, Paola; Gaudiosi, Germana; Lombardi, Giovanni; Nappi, Rosa; Salvemini, Raffaella; Spiga, Efisio

    2016-04-01

    This paper, by means of a multidisciplinary approach, deals with changes of the urban and territorial setting in many localities of the epicentral area of the 23 November 1980 Irpinia earthquake. The 23 November 1980 earthquake, known as the "Irpinia-Basilicata earthquake" was the strongest seismic event of the last 80 years in the Southern Apennines of Italy (Mw 6.9, I0=X MCS). It was felt nearly everywhere in Italy, from Sicily in the South, to Emilia Romagna and Liguria in the North. This earthquake was characterized by a complex main rupture, composed of three major sub-events, interpreted as a succession of normal faulting events. Many localities in the Avellino, Salerno and Potenza provinces were nearly completely destroyed (I=IX-X MSK, Postpischl et al., 1985); among them Castelnuovo di Conza, Conza della Campania, Lioni, Santomenna, San Mango sul Calore, San Michele di Serino and Sant'Angelo dei Lombardi. About 800 localities suffered serious damage (Balvano, Bisaccia, Calitri, etc); 75,000 houses collapsed totally and 275,000 were badly damaged. Casualties were 3000, and 10,000 people were wounded. A large amount of information on primary and secondary environmental effects, over all slope movements, was available on the basis of several geological surveys of the area affected by this earthquake. The amount of surface faulting was about 40 km in length and the maximum displacement about 100 cm, while the total area interested by slope movements was estimated in 7400 km2 (Porfido et al., 2002, 2007; Serva et al.2009). In this study we aim to describe trends and specific effects that have taken place in the 35 years following the 1980 earthquake: how the urban and territorial setting have changed, especially in the villages located in the epicentral area; the consequences of the environmental effects on the choices of reconstruction, both in situ, and far from the original historical centre. Therefore, some case histories as San Mango sul Calore and Calitri

  18. Precise Relative Earthquake Magnitudes from Cross Correlation

    DOE PAGES

    Cleveland, K. Michael; Ammon, Charles J.

    2015-04-21

    We present a method to estimate precise relative magnitudes using cross correlation of seismic waveforms. Our method incorporates the intercorrelation of all events in a group of earthquakes, as opposed to individual event pairings relative to a reference event. This method works well when a reliable reference event does not exist. We illustrate the method using vertical strike-slip earthquakes located in the northeast Pacific and Panama fracture zone regions. Our results are generally consistent with the Global Centroid Moment Tensor catalog, which we use to establish a baseline for the relative event sizes.

  19. Astrophysical phenomena related to supermassive black holes

    NASA Astrophysics Data System (ADS)

    Pott, Jörg-Uwe

    2006-12-01

    reactions in stars. In the most active galaxies known, the radiating accretion disc of the central SMBH engine easily outshines the stellar light of the entire galaxy (Blandford 1995). In addition to the light, plasma streams can emerge from the innermost regions at relativistic velocities, returning energy to the host galaxy (host) and creating jets and lobes with strong observational signatures, especially at radio and X-ray wavelengths (Wilson 2003). New insights in the wide field of SMBH/host interaction are often related to the development of new, more sensitive instruments and telescopes. For example the idea, that a high luminosity AGN may result from a merger event between two galaxies, could only develop with the upcoming high resolution and sensitive imaging capabilities needed to detect the highly distorted host galaxy morphologies of (post-)merger galaxies (Heckman et al. 1986). Furthermore multi-wavelength approaches, which combine the results of measurements at different wavelengths, often lead to new conclusions or confirm unsecured hypotheses. Thus developing a new instrument can be as valuable as combining different datasets. I follow both approaches and developed projects which (i) deal with new instrumentation and telescope technology, (ii) combine datasets from different wavelengths and resolutions, and (iii) incorporate recent theoretical models and predictions, which can be verified empirically. While some projects are more focused on investigating the power of new observational techniques, others incorporate acknowledged instruments to probe predictions based on previous observations and models and trace special phenomena of SMBH/host interaction. But in most cases aspects of all three items appear. The SMBH/host interaction results in phenomena at all linear size scales of the system, from the direct accretion of matter onto the central black hole up to radio jets crossing the entire galaxy. Thus interaction effects do not simply concentrate on the

  20. Statistical validation of earthquake related observations

    NASA Astrophysics Data System (ADS)

    Kossobokov, V. G.

    2011-12-01

    optional "antipodal strategy", one can make the predictions efficient, so that the wins will systematically outscore the losses. Sounds easy, however, many precursor phenomena are lacking info on a rigorous control and, in many cases, even the necessary precondition of any scientific study, i.e., an unambiguous definition of "precursor/signal". On the other hand, understanding the complexity of seismic process along with its non-stationary hierarchically organized behaviors, has led already to reproducible intermediate-term middle-range earthquake prediction technique that has passed control test in forward real-time applications during at least the last two decades. In particular, place and time of each of the mega earthquakes of 27 February 2010 in Chile and 11 March 2011 in Japan were recognized as in state of increased probability of such events in advance their occurrences in the ongoing since 1992 Global Test of the algorithms M8 and MSc. These evidences, in conjunction with a retrospective analysis of seismic activity preceding 26 December 2004 in the Indian Ocean and other mega earthquakes of the 20th century, give grounds for assuming that the algorithms of validated effectiveness in magnitude ranges M7.5+ and M8.0+ are applicable to predict the mega-earthquakes as well.

  1. Investigation of ionospheric precursors related to deep and intermediate earthquakes based on spectral and statistical analysis

    NASA Astrophysics Data System (ADS)

    Oikonomou, Christina; Haralambous, Haris; Muslim, Buldan

    2017-01-01

    Ionospheric TEC (Total Electron Content) variations prior to the deep (≈600 km) earthquake doublet close to magnetic equator in Peru (M = 7.6) and to the intermediate (≈200 km) earthquake in Afghanistan (M = 7.5) during 2015 were investigated using measurements from Global Navigation Satellite System (GNSS) network with the aim to detect possible ionospheric precursors of these events. For this we applied both statistical and spectral analysis. Ionospheric anomalies related to both earthquakes were observed few hours and few days prior to the earthquakes during daytime localized mainly near the epicenter. These were large-scale positive TEC anomalies and small-scale TEC oscillations with periods of 20 min and duration around 2-4 h appearing at the same local time each day. Several days prior to the earthquake in Peru a significant phenomenon was observed during afternoon time related to the modification of the Equatorial Ionization Anomaly (EIA) structure. During nighttime, however, it was not possible to identify any ionospheric earthquake precursor due to the concurrence of various phenomena, such as Equatorial Plasma Bubbles and pre- and post-midnight TEC peaks prior to Peru earthquake, and solar terminator transition prior to both earthquakes which could induce resembling ionospheric anomalies.

  2. The surface latent heat flux anomalies related to major earthquake

    NASA Astrophysics Data System (ADS)

    Jing, Feng; Shen, Xuhui; Kang, Chunli; Xiong, Pan; Hong, Shunying

    2011-12-01

    SLHF (Surface Latent Heat Flux) is an atmospheric parameter, which can describe the heat released by phase changes and dependent on meteorological parameters such as surface temperature, relative humidity, wind speed etc. There is a sharp difference between the ocean surface and the land surface. Recently, many studies related to the SLHF anomalies prior to earthquakes have been developed. It has been shown that the energy exchange enhanced between coastal surface and atmosphere prior to earthquakes can increase the rate of the water-heat exchange, which will lead to an obviously increases in SLHF. In this paper, two earthquakes in 2010 (Haiti earthquake and southwest of Sumatra in Indonesia earthquake) have been analyzed using SLHF data by STD (standard deviation) threshold method. It is shows that the SLHF anomaly may occur in interpolate earthquakes or intraplate earthquakes and coastal earthquakes or island earthquakes. And the SLHF anomalies usually appear 5-6 days prior to an earthquake, then disappear quickly after the event. The process of anomaly evolution to a certain extent reflects a dynamic energy change process about earthquake preparation, that is, weak-strong-weak-disappeared.

  3. One research from turkey on groundwater- level changes related earthquake

    NASA Astrophysics Data System (ADS)

    Kirmizitas, H.; Göktepe, G.

    2003-04-01

    Groundwater levels are recorded by limnigraphs in drilling wells in order to determine groundwater potential accurately and reliable under hydrogeological studies in Turkey State Haydraulic Works (DSI) set the limnigraphs to estimate mainly groundwater potential. Any well is drilled to determine and to obtain data on water level changes related earthquake up today. The main purpose of these studies are based on groundwater potential and to expose the hydrodynamic structure of an aquifer. In this study, abnormal oscillations, water rising and water drops were observed on graphs which is related with water level changes in groundwater. These observations showed that, some earthquakes has been effective on water level changes. There is a distance ranging to 2000 km between this epicentral and water wells. Water level changes occur in groundwater bearing layers that could be consisting of grained materials such as, alluvium or consolidated rocks such as, limestones. The biggest water level change is ranging to 1,48 m on diagrams and it is recorded as oscillation movement. Water level changes related earthquake are observed in different types of movements below in this research. 1-Rise-drop oscillation changes on same point. 2-Water level drop in certain periods or permanent periods after earthquakes. 3-Water level rise in certain periods or permanent periods after earthquakes. (For example, during Gölcük Earthquake with magnitude of 7.8 on August, 17, 1999 one artesian occured in DSI well ( 49160 numbered ) in Adapazari, Dernekkiri Village. Groundwater level changes might easily be changed because of atmosferic pressure that comes in first range, precipitation, irrigation or water pumping. Owing to relate groundwater level changes with earthquake on any time, such changes should be observed accurately, carefully and at right time. Thus, first of all, the real reason of this water level changes must be determined From 1970 to 2001 many earthquakes occured in Turkey

  4. Earthquakes

    MedlinePlus

    ... Search Term(s): Main Content Home Be Informed Earthquakes Earthquakes An earthquake is the sudden, rapid shaking of the earth, ... by the breaking and shifting of underground rock. Earthquakes can cause buildings to collapse and cause heavy ...

  5. Seasonality of alcohol-related phenomena in Estonia.

    PubMed

    Silm, Siiri; Ahas, Rein

    2005-03-01

    We studied alcohol consumption and its consequences as a seasonal phenomenon in Estonia and analysed the social and environmental factors that may cause its seasonal rhythm. There are two important questions when researching the seasonality of human activities: (1) whether it is caused by natural or social factors, and (2) whether the impact of the factors is direct or indirect. Often the seasonality of social phenomena is caused by social factors, but the triggering mechanisms are related to environmental factors like temperature, precipitation, and radiation via the circannual calendar. The indicators of alcohol consumption in the current paper are grouped as: (1) pre-consumption phenomena, i.e. production, tax and excise, sales (beer, wine and vodka are analysed separately), and (2) post-consumption phenomena, i.e. alcohol-related crime and traffic accidents and the number of people detained in lockups and admitted to alcohol treatment clinics. In addition, seasonal variability in the amount of alcohol advertising has been studied, and a survey has been carried out among 87 students of Tartu University. The analysis shows that different phenomena related to alcohol have a clear seasonal rhythm in Estonia. The peak period of phenomena related to beer is in the summer, from June to August and the low point is during the first months of the year. Beer consumption correlates well with air temperature. The consumption of vodka increases sharply at the end of the year and in June; the production of vodka does not have a significant correlation with negative temperatures. The consumption of wine increases during summer and in December. The consequences of alcohol consumption, expressed as the rate of traffic accidents or the frequency of medical treatment, also show seasonal variability. Seasonal variability of alcohol consumption in Estonia is influenced by natural factors (temperature, humidity, etc.) and by social factors (celebrations, vacations, etc.). However

  6. Seasonality of alcohol-related phenomena in Estonia

    NASA Astrophysics Data System (ADS)

    Silm, Siiri; Ahas, Rein

    2005-03-01

    We studied alcohol consumption and its consequences as a seasonal phenomenon in Estonia and analysed the social and environmental factors that may cause its seasonal rhythm. There are two important questions when researching the seasonality of human activities: (1) whether it is caused by natural or social factors, and (2) whether the impact of the factors is direct or indirect. Often the seasonality of social phenomena is caused by social factors, but the triggering mechanisms are related to environmental factors like temperature, precipitation, and radiation via the circannual calendar. The indicators of alcohol consumption in the current paper are grouped as: (1) pre-consumption phenomena, i.e. production, tax and excise, sales (beer, wine and vodka are analysed separately), and (2) post-consumption phenomena, i.e. alcohol-related crime and traffic accidents and the number of people detained in lockups and admitted to alcohol treatment clinics. In addition, seasonal variability in the amount of alcohol advertising has been studied, and a survey has been carried out among 87 students of Tartu University. The analysis shows that different phenomena related to alcohol have a clear seasonal rhythm in Estonia. The peak period of phenomena related to beer is in the summer, from June to August and the low point is during the first months of the year. Beer consumption correlates well with air temperature. The consumption of vodka increases sharply at the end of the year and in June; the production of vodka does not have a significant correlation with negative temperatures. The consumption of wine increases during summer and in December. The consequences of alcohol consumption, expressed as the rate of traffic accidents or the frequency of medical treatment, also show seasonal variability. Seasonal variability of alcohol consumption in Estonia is influenced by natural factors (temperature, humidity, etc.) and by social factors (celebrations, vacations, etc.). However

  7. Analysis on Two Typical Landslide Hazard Phenomena in The Wenchuan Earthquake by Field Investigations and Shaking Table Tests.

    PubMed

    Yang, Changwei; Zhang, Jianjing; Liu, Feicheng; Bi, Junwei; Jun, Zhang

    2015-08-06

    Based on our field investigations of landslide hazards in the Wenchuan earthquake, some findings can be reported: (1) the multi-aspect terrain facing empty isolated mountains and thin ridges reacted intensely to the earthquake and was seriously damaged; (2) the slope angles of most landslides was larger than 45°. Considering the above disaster phenomena, the reasons are analyzed based on shaking table tests of one-sided, two-sided and four-sided slopes. The analysis results show that: (1) the amplifications of the peak accelerations of four-sided slopes is stronger than that of the two-sided slopes, while that of the one-sided slope is the weakest, which can indirectly explain the phenomena that the damage is most serious; (2) the amplifications of the peak accelerations gradually increase as the slope angles increase, and there are two inflection points which are the point where the slope angle is 45° and where the slope angle is 50°, respectively, which can explain the seismic phenomenon whereby landslide hazards mainly occur on the slopes whose slope angle is bigger than 45°. The amplification along the slope strike direction is basically consistent, and the step is smooth.

  8. Analysis on Two Typical Landslide Hazard Phenomena in The Wenchuan Earthquake by Field Investigations and Shaking Table Tests

    PubMed Central

    Yang, Changwei; Zhang, Jianjing; Liu, Feicheng; Bi, Junwei; Jun, Zhang

    2015-01-01

    Based on our field investigations of landslide hazards in the Wenchuan earthquake, some findings can be reported: (1) the multi-aspect terrain facing empty isolated mountains and thin ridges reacted intensely to the earthquake and was seriously damaged; (2) the slope angles of most landslides was larger than 45°. Considering the above disaster phenomena, the reasons are analyzed based on shaking table tests of one-sided, two-sided and four-sided slopes. The analysis results show that: (1) the amplifications of the peak accelerations of four-sided slopes is stronger than that of the two-sided slopes, while that of the one-sided slope is the weakest, which can indirectly explain the phenomena that the damage is most serious; (2) the amplifications of the peak accelerations gradually increase as the slope angles increase, and there are two inflection points which are the point where the slope angle is 45° and where the slope angle is 50°, respectively, which can explain the seismic phenomenon whereby landslide hazards mainly occur on the slopes whose slope angle is bigger than 45°. The amplification along the slope strike direction is basically consistent, and the step is smooth. PMID:26258785

  9. Comparison of the sand liquefaction estimated based on codes and practical earthquake damage phenomena

    NASA Astrophysics Data System (ADS)

    Fang, Yi; Huang, Yahong

    2017-12-01

    Conducting sand liquefaction estimated based on codes is the important content of the geotechnical design. However, the result, sometimes, fails to conform to the practical earthquake damages. Based on the damage of Tangshan earthquake and engineering geological conditions, three typical sites are chosen. Moreover, the sand liquefaction probability was evaluated on the three sites by using the method in the Code for Seismic Design of Buildings and the results were compared with the sand liquefaction phenomenon in the earthquake. The result shows that the difference between sand liquefaction estimated based on codes and the practical earthquake damage is mainly attributed to the following two aspects: The primary reasons include disparity between seismic fortification intensity and practical seismic oscillation, changes of groundwater level, thickness of overlying non-liquefied soil layer, local site effect and personal error. Meanwhile, although the judgment methods in the codes exhibit certain universality, they are another reason causing the above difference due to the limitation of basic data and the qualitative anomaly of the judgment formulas.

  10. PEER - January 12, 2010 Haiti Earthquake - Related Events

    Related Events Related Events Preliminary Reconnaissance Presentation about Chile Earthquake Tuesday Topic: Chile EERI/PEER Reconnaissance Briefing Date: Tuesday, March 30, 2010 Time: 3:00 PM to 5PM

  11. A Review of Low Frequency Electromagnetic Wave Phenomena Related to Tropospheric-Ionospheric Coupling Mechanisms

    NASA Technical Reports Server (NTRS)

    Simoes, Fernando; Pfaff, Robert; Berthelier, Jean-Jacques; Klenzing, Jeffrey

    2012-01-01

    Investigation of coupling mechanisms between the troposphere and the ionosphere requires a multidisciplinary approach involving several branches of atmospheric sciences, from meteorology, atmospheric chemistry, and fulminology to aeronomy, plasma physics, and space weather. In this work, we review low frequency electromagnetic wave propagation in the Earth-ionosphere cavity from a troposphere-ionosphere coupling perspective. We discuss electromagnetic wave generation, propagation, and resonance phenomena, considering atmospheric, ionospheric and magnetospheric sources, from lightning and transient luminous events at low altitude to Alfven waves and particle precipitation related to solar and magnetospheric processes. We review in situ ionospheric processes as well as surface and space weather phenomena that drive troposphere-ionosphere dynamics. Effects of aerosols, water vapor distribution, thermodynamic parameters, and cloud charge separation and electrification processes on atmospheric electricity and electromagnetic waves are reviewed. We also briefly revisit ionospheric irregularities such as spread-F and explosive spread-F, sporadic-E, traveling ionospheric disturbances, Trimpi effect, and hiss and plasma turbulence. Regarding the role of the lower boundary of the cavity, we review transient surface phenomena, including seismic activity, earthquakes, volcanic processes and dust electrification. The role of surface and atmospheric gravity waves in ionospheric dynamics is also briefly addressed. We summarize analytical and numerical tools and techniques to model low frequency electromagnetic wave propagation and solving inverse problems and summarize in a final section a few challenging subjects that are important for a better understanding of tropospheric-ionospheric coupling mechanisms.

  12. Earthquakes

    MedlinePlus

    An earthquake happens when two blocks of the earth suddenly slip past one another. Earthquakes strike suddenly, violently, and without warning at any time of the day or night. If an earthquake occurs in a populated area, it may cause ...

  13. Earthquake-related versus non-earthquake-related injuries in spinal injury patients: differentiation with multidetector computed tomography

    PubMed Central

    2010-01-01

    Introduction In recent years, several massive earthquakes have occurred across the globe. Multidetector computed tomography (MDCT) is reliable in detecting spinal injuries. The purpose of this study was to compare the features of spinal injuries resulting from the Sichuan earthquake with those of non-earthquake-related spinal trauma using MDCT. Methods Features of spinal injuries of 223 Sichuan earthquake-exposed patients and 223 non-earthquake-related spinal injury patients were retrospectively compared using MDCT. The date of non-earthquake-related spinal injury patients was collected from 1 May 2009 to 22 July 2009 to avoid the confounding effects of seasonal activity and clothing. We focused on anatomic sites, injury types and neurologic deficits related to spinal injuries. Major injuries were classified according to the grid 3-3-3 scheme of the Magerl (AO) classification system. Results A total of 185 patients (82.96%) in the earthquake-exposed cohort experienced crush injuries. In the earthquake and control groups, 65 and 92 patients, respectively, had neurologic deficits. The anatomic distribution of these two cohorts was significantly different (P < 0.001). Cervical spinal injuries were more common in the control group (risk ratio (RR) = 2.12, P < 0.001), whereas lumbar spinal injuries were more common in the earthquake-related spinal injuries group (277 of 501 injured vertebrae; 55.29%). The major types of injuries were significantly different between these cohorts (P = 0.002). Magerl AO type A lesions composed most of the lesions seen in both of these cohorts. Type B lesions were more frequently seen in earthquake-related spinal injuries (RR = 1.27), while we observed type C lesions more frequently in subjects with non-earthquake-related spinal injuries (RR = 1.98, P = 0.0029). Conclusions Spinal injuries sustained in the Sichuan earthquake were located mainly in the lumbar spine, with a peak prevalence of type A lesions and a high occurrence of

  14. Intermediate-depth earthquakes facilitated by eclogitization-related stresses

    Nakajima, Junichi; Uchida, Naoki; Shiina, Takahiro; Hasegawa, Akira; Hacker, Bradley R.; Kirby, Stephen H.

    2013-01-01

    Eclogitization of the basaltic and gabbroic layer in the oceanic crust involves a volume reduction of 10%–15%. One consequence of the negative volume change is the formation of a paired stress field as a result of strain compatibility across the reaction front. Here we use waveform analysis of a tiny seismic cluster in the lower crust of the downgoing Pacific plate and reveal new evidence in favor of this mechanism: tensional earthquakes lying 1 km above compressional earthquakes, and earthquakes with highly similar waveforms lying on well-defined planes with complementary rupture areas. The tensional stress is interpreted to be caused by the dimensional mismatch between crust transformed to eclogite and underlying untransformed crust, and the earthquakes are probably facilitated by reactivation of fossil faults extant in the subducting plate. These observations provide seismic evidence for the role of volume change–related stresses and, possibly, fluid-related embrittlement as viable processes for nucleating earthquakes in downgoing oceanic lithosphere.

  15. Comparative study of earthquake-related and non-earthquake-related head traumas using multidetector computed tomography

    PubMed Central

    Chu, Zhi-gang; Yang, Zhi-gang; Dong, Zhi-hui; Chen, Tian-wu; Zhu, Zhi-yu; Shao, Heng

    2011-01-01

    OBJECTIVE: The features of earthquake-related head injuries may be different from those of injuries obtained in daily life because of differences in circumstances. We aim to compare the features of head traumas caused by the Sichuan earthquake with those of other common head traumas using multidetector computed tomography. METHODS: In total, 221 patients with earthquake-related head traumas (the earthquake group) and 221 patients with other common head traumas (the non-earthquake group) were enrolled in our study, and their computed tomographic findings were compared. We focused the differences between fractures and intracranial injuries and the relationships between extracranial and intracranial injuries. RESULTS: More earthquake-related cases had only extracranial soft tissue injuries (50.7% vs. 26.2%, RR = 1.9), and fewer cases had intracranial injuries (17.2% vs. 50.7%, RR = 0.3) compared with the non-earthquake group. For patients with fractures and intracranial injuries, there were fewer cases with craniocerebral injuries in the earthquake group (60.6% vs. 77.9%, RR = 0.8), and the earthquake-injured patients had fewer fractures and intracranial injuries overall (1.5±0.9 vs. 2.5±1.8; 1.3±0.5 vs. 2.1±1.1). Compared with the non-earthquake group, the incidences of soft tissue injuries and cranial fractures combined with intracranial injuries in the earthquake group were significantly lower (9.8% vs. 43.7%, RR = 0.2; 35.1% vs. 82.2%, RR = 0.4). CONCLUSION: As depicted with computed tomography, the severity of earthquake-related head traumas in survivors was milder, and isolated extracranial injuries were more common in earthquake-related head traumas than in non-earthquake-related injuries, which may have been the result of different injury causes, mechanisms and settings. PMID:22012045

  16. Surface Rupture Effects on Earthquake Moment-Area Scaling Relations

    NASA Astrophysics Data System (ADS)

    Luo, Yingdi; Ampuero, Jean-Paul; Miyakoshi, Ken; Irikura, Kojiro

    2017-09-01

    Empirical earthquake scaling relations play a central role in fundamental studies of earthquake physics and in current practice of earthquake hazard assessment, and are being refined by advances in earthquake source analysis. A scaling relation between seismic moment ( M 0) and rupture area ( A) currently in use for ground motion prediction in Japan features a transition regime of the form M 0- A 2, between the well-recognized small (self-similar) and very large (W-model) earthquake regimes, which has counter-intuitive attributes and uncertain theoretical underpinnings. Here, we investigate the mechanical origin of this transition regime via earthquake cycle simulations, analytical dislocation models and numerical crack models on strike-slip faults. We find that, even if stress drop is assumed constant, the properties of the transition regime are controlled by surface rupture effects, comprising an effective rupture elongation along-dip due to a mirror effect and systematic changes of the shape factor relating slip to stress drop. Based on this physical insight, we propose a simplified formula to account for these effects in M 0- A scaling relations for strike-slip earthquakes.

  17. Earthquakes.

    ERIC Educational Resources Information Center

    Pakiser, Louis C.

    One of a series of general interest publications on science topics, the booklet provides those interested in earthquakes with an introduction to the subject. Following a section presenting an historical look at the world's major earthquakes, the booklet discusses earthquake-prone geographic areas, the nature and workings of earthquakes, earthquake…

  18. Earthquakes.

    ERIC Educational Resources Information Center

    Walter, Edward J.

    1977-01-01

    Presents an analysis of the causes of earthquakes. Topics discussed include (1) geological and seismological factors that determine the effect of a particular earthquake on a given structure; (2) description of some large earthquakes such as the San Francisco quake; and (3) prediction of earthquakes. (HM)

  19. Transport-related impacts of the Northridge Earthquake

    DOT National Transportation Integrated Search

    1998-05-01

    This research estimates the transport-related business interruption impacts of the 1994 Northridge earthquake using a spatial allocation model, SCPM (the Southern California Planning Model) and surveys of businesses and individuals. Total business in...

  20. Causal relations among events and states in dynamic geographical phenomena

    NASA Astrophysics Data System (ADS)

    Huang, Zhaoqiang; Feng, Xuezhi; Xuan, Wenling; Chen, Xiuwan

    2007-06-01

    There is only a static state of the real world to be recorded in conventional geographical information systems. However, there is not only static information but also dynamic information in geographical phenomena. So that how to record the dynamic information and reveal the relations among dynamic information is an important issue in a spatio-temporal information system. From an ontological perspective, we can initially divide the spatio-temporal entities in the world into continuants and occurrents. Continuant entities endure through some extended (although possibly very short) interval of time (e.g., houses, roads, cities, and real-estate). Occurrent entities happen and are then gone (e.g., a house repair job, road construction project, urban expansion, real-estate transition). From an information system perspective, continuants and occurrents that have a unique identity in the system are referred to as objects and events, respectively. And the change is represented implicitly by static snapshots in current spatial temporal information systems. In the previous models, the objects can be considered as the fundamental components of the system, and the change is modeled by considering time-varying attributes of these objects. In the spatio-temporal database, the temporal information that is either interval or instant is involved and the underlying data structures and indexes for temporal are considerable investigated. However, there is the absence of explicit ways of considering events, which affect the attributes of objects or the state. So the research issue of this paper focuses on how to model events in conceptual models of dynamic geographical phenomena and how to represent the causal relations among events and the objects or states. Firstly, the paper reviews the conceptual modeling in a temporal GIS by researchers. Secondly, this paper discusses the spatio-temporal entities: objects and events. Thirdly, this paper investigates the causal relations amongst

  1. Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography.

    PubMed

    Dong, Zhi-Hui; Yang, Zhi-Gang; Chen, Tian-Wu; Chu, Zhi-Gang; Deng, Wen; Shao, Heng

    2011-01-01

    Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR=1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR=1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR= 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR= 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR=1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries.

  2. Thoracic Injuries in earthquake-related versus non-earthquake-related trauma patients: differentiation via Multi-detector Computed Tomography

    PubMed Central

    Dong, Zhi-hui; Yang, Zhi-gang; Chen, Tian-wu; Chu, Zhi-gang; Deng, Wen; Shao, Heng

    2011-01-01

    PURPOSE: Massive earthquakes are harmful to humankind. This study of a historical cohort aimed to investigate the difference between earthquake-related crush thoracic traumas and thoracic traumas unrelated to earthquakes using a multi-detector Computed Tomography (CT). METHODS: We retrospectively compared an earthquake-exposed cohort of 215 thoracic trauma crush victims of the Sichuan earthquake to a cohort of 215 non-earthquake-related thoracic trauma patients, focusing on the lesions and coexisting injuries to the thoracic cage and the pulmonary parenchyma and pleura using a multi-detector CT. RESULTS: The incidence of rib fracture was elevated in the earthquake-exposed cohort (143 vs. 66 patients in the non-earthquake-exposed cohort, Risk Ratio (RR) = 2.2; p<0.001). Among these patients, those with more than 3 fractured ribs (106/143 vs. 41/66 patients, RR = 1.2; p<0.05) or flail chest (45/143 vs. 11/66 patients, RR = 1.9; p<0.05) were more frequently seen in the earthquake cohort. Earthquake-related crush injuries more frequently resulted in bilateral rib fractures (66/143 vs. 18/66 patients, RR = 1.7; p<0.01). Additionally, the incidence of non-rib fracture was higher in the earthquake cohort (85 vs. 60 patients, RR = 1.4; p<0.01). Pulmonary parenchymal and pleural injuries were more frequently seen in earthquake-related crush injuries (117 vs. 80 patients, RR = 1.5 for parenchymal and 146 vs. 74 patients, RR = 2.0 for pleural injuries; p<0.001). Non-rib fractures, pulmonary parenchymal and pleural injuries had significant positive correlation with rib fractures in these two cohorts. CONCLUSIONS: Thoracic crush traumas resulting from the earthquake were life threatening with a high incidence of bony thoracic fractures. The ribs were frequently involved in bilateral and severe types of fractures, which were accompanied by non-rib fractures, pulmonary parenchymal and pleural injuries. PMID:21789386

  3. The escaping "pneuma" - gas of ancient earthquake concepts in relation to animal, atmospheric and thermal precursors

    NASA Astrophysics Data System (ADS)

    Helmut, Tributsch

    2013-04-01

    The escaping "pneuma" - gas of ancient earthquake concepts in relation to animal, atmospheric and thermal precursors Helmut Tributsch Present affiliation: Carinthian University for Applied Sciences, Bio-mimetics program, Europastrasse 4, 9524 Villach, Austria, helmut.tributsch@alice.it Retired from: Free University Berlin, Institute for physical and theoretical chemistry, Takustr. 3, 14195 Berlin, Germany. For two thousand years ancient European and medieval (including islamic) natural philosophers have considered a dry, warm gas, the "pneuma" ( breath, exhalation), escaping from the earth, as precursor and trigger of earthquakes. Also in China an escaping gas or breath (the qi) was considered the cause of earthquake, first in a document from 780 BC. We know today that escaping gas is not causing earthquakes. But it may be that natural phenomena that supported such a pneuma-concept have again and again been observed. The unpolluted environment and the largely absence of distracting artificial stimuli may have allowed the recognition of distinct earthquake precursors, such as described by ancient observers: (1) the sun becomes veiled and has a dim appearance, turns reddish or dark (2) a narrow long stretched cloud becomes visible, like a line drawn by a ruler, (3) earthquakes preceded by a thin streak of cloud stretching over a wide space. (4) earthquakes in the morning sometimes preceded by a still and a strong frost, (5) a surf - line of the air sea is forming (near the horizon). The described phenomena may be interpreted as a kind of smog forming above the ground prior to an earthquake, a smog exhaled from the ground, which is triggering water condensation, releasing latent heat, changing visibility, temperature, heat conduction and radiation properties. This could perfectly match the phenomenon, which is at the origin of satellite monitored temperature anomalies preceding earthquakes. Based on a few examples it will be shown that the time window of temperature

  4. Nature of Pre-Earthquake Phenomena and their Effects on Living Organisms

    PubMed Central

    Freund, Friedemann; Stolc, Viktor

    2013-01-01

    Simple Summary Earthquakes are invariably preceded by a period when stresses increase deep in the Earth. Animals appear to be able to sense impending seismic events. During build-up of stress, electronic charge carriers are activated deep below, called positive holes. Positive holes have unusual properties: they can travel fast and far into and through the surrounding rocks. As they flow, they generate ultralow frequency electromagnetic waves. When they arrive at the Earth surface, they can ionize the air. When they flow into water, they oxidize it to hydrogen peroxides. All these physical and chemical processes can have noticeable effects on animals. Abstract Earthquakes occur when tectonic stresses build up deep in the Earth before catastrophic rupture. During the build-up of stress, processes that occur in the crustal rocks lead to the activation of highly mobile electronic charge carriers. These charge carriers are able to flow out of the stressed rock volume into surrounding rocks. Such outflow constitutes an electric current, which generates electromagnetic (EM) signals. If the outflow occurs in bursts, it will lead to short EM pulses. If the outflow is continuous, the currents may fluctuate, generating EM emissions over a wide frequency range. Only ultralow and extremely low frequency (ULF/ELF) waves travel through rock and can reach the Earth surface. The outflowing charge carriers are (i) positively charged and (ii) highly oxidizing. When they arrive at the Earth surface from below, they build up microscopic electric fields, strong enough to field-ionize air molecules. As a result, the air above the epicentral region of an impending major earthquake often becomes laden with positive airborne ions. Medical research has long shown that positive airborne ions cause changes in stress hormone levels in animals and humans. In addition to the ULF/ELF emissions, positive airborne ions can cause unusual reactions among animals. When the charge carriers flow into

  5. Non-Seismic Pre-Earthquake Phenomena and their Effects on the Biosphere

    NASA Astrophysics Data System (ADS)

    Freund, Friedemann; Stolc, Viktor

    2013-04-01

    Earthquakes occur when tectonic stresses build up deep in the Earth and reach the threshold of catastrophic rupture. During the build-up of stress, long before rupture, processes occur in the Earth crust that lead to the activation of highly mobile electronic charge carriers. One remarkable property of these charge carriers is that they are able to flow out of the stressed rock volume into surrounding rocks. Such an outflow constitutes an electric current, which generates electromagnetic (EM) signals. If the outflow occurs in bursts, the EM signals will consist of short EM pulses. If the outflow is continuous, the currents are likely to fluctuate, generating EM emissions over a wide frequency range. Only the ultralow and extremely low frequency (ULF/ELF) waves can travel through kilometers of rock and reach the Earth surface. These ULF/ELF emissions can last for hours or days. In a companion poster we report on their effects on crucial biochemical reactions in living organisms. Another remarkable property of the outflowing charge carriers is that they are (i) positively charged and (ii) highly oxidizing. When they reach the Earth surface from below, they build up microscopic but very steep electric fields, strong enough to field-ionize air molecules, i.e. rip an electron off air molecules. As a result the air above the epicenter of an impending major earthquake often becomes heavily laden with positive airborne ions. Medical research has long shown that positive airborne ions cause changes in the stress hormone level in animals and humans. Therefore, positive airborne ions are a likely cause for unusual reactions among animals and humans. When the outflowing charge carriers cross from rocks into water, they oxidize the water to hydrogen peroxide. This process, plus oxidation reactions involving dissolved organic compounds in the ground water, are likely candidates for causing behavioral changes, even death, among aquatic animals.

  6. [Adhesive properties and related phenomena for powdered pharmaceuticals].

    PubMed

    Otsuka, A

    1998-04-01

    This report deals with adhesive properties and related phenomena of powdered materials including pharmaceuticals. The adhesive force between a powder particle and substrate as well as the tensile strength of a powder bed and tablet was measured. Various factors were found to affect powder adhesion. Physical properties such as the size, shape and surface roughness were examined. The adhesive force between a particle and substrate decreased remarkably in the presence of ultrafine particles, which is of interest since the addition of adequate amount of "glidant" causes an increase in powder fluidity. From a pharmaceutical point of view, temperature and humidity were essential to particle adhesion. For several organic substances, the adhesive force increased significantly at homologous temperatures more than ca. 0.7, suggesting the sintering mechanism to be operative. The adhsive force between polymer films and glass beads varied according to polymer and relative humidity. A close correlation of water sorbed by the polymer film with adhesive force was noted. In connection with powder fluidity, compaction properties were studied by the centrifugal and tapping methods. Apparent adhesion defined as the ratio of the adhesive force between two contacting particles to the external force acting on a particle was noted to be the primary determinant of the void fraction or the porosity of the powder bed, indicating that the probability of particle displacement essentially depended on apparent adhesion.

  7. Relating triggering processes in lab experiments with earthquakes.

    NASA Astrophysics Data System (ADS)

    Baro Urbea, J.; Davidsen, J.; Kwiatek, G.; Charalampidou, E. M.; Goebel, T.; Stanchits, S. A.; Vives, E.; Dresen, G.

    2016-12-01

    Statistical relations such as Gutenberg-Richter's, Omori-Utsu's and the productivity of aftershocks were first observed in seismology, but are also common to other physical phenomena exhibiting avalanche dynamics such as solar flares, rock fracture, structural phase transitions and even stock market transactions. All these examples exhibit spatio-temporal correlations that can be explained as triggering processes: Instead of being activated as a response to external driving or fluctuations, some events are consequence of previous activity. Although different plausible explanations have been suggested in each system, the ubiquity of such statistical laws remains unknown. However, the case of rock fracture may exhibit a physical connection with seismology. It has been suggested that some features of seismology have a microscopic origin and are reproducible over a vast range of scales. This hypothesis has motivated mechanical experiments to generate artificial catalogues of earthquakes at a laboratory scale -so called labquakes- and under controlled conditions. Microscopic fractures in lab tests release elastic waves that are recorded as ultrasonic (kHz-MHz) acoustic emission (AE) events by means of piezoelectric transducers. Here, we analyse the statistics of labquakes recorded during the failure of small samples of natural rocks and artificial porous materials under different controlled compression regimes. Temporal and spatio-temporal correlations are identified in certain cases. Specifically, we distinguish between the background and triggered events, revealing some differences in the statistical properties. We fit the data to statistical models of seismicity. As a particular case, we explore the branching process approach simplified in the Epidemic Type Aftershock Sequence (ETAS) model. We evaluate the empirical spatio-temporal kernel of the model and investigate the physical origins of triggering. Our analysis of the focal mechanisms implies that the occurrence

  8. Presenteeism and absenteeism: differentiated understanding of related phenomena.

    PubMed

    Gosselin, Eric; Lemyre, Louise; Corneil, Wayne

    2013-01-01

    In the past it was assumed that work attendance equated to performance. It now appears that health-related loss of productivity can be traced equally to workers showing up at work as well as to workers choosing not to. Presenteeism in the workplace, showing up for work while sick, seems now more prevalent than absenteeism. These findings are forcing organizations to reconsider their approaches regarding regular work attendance. Given this, and echoing recommendations in the literature, this study seeks to identify the main behavioral correlates of presenteeism and absenteeism in the workplace. Comparative analysis of the data from a representative sample of executives from the Public Service of Canada enables us to draw a unique picture of presenteeism and absenteeism with regards not only to the impacts of health disorders but also to the demographic, organizational, and individual factors involved. Results provide a better understanding of the similarities and differences between these phenomena, and more specifically, of the differentiated influence of certain variables. These findings provide food for thought and may pave the way to the development of new organizational measures designed to manage absenteeism without creating presenteeism.

  9. Recognition of earthquake-related damage in archaeological sites: Examples from the Dead Sea fault zone

    NASA Astrophysics Data System (ADS)

    Marco, Shmuel

    2008-06-01

    Archaeological structures that exhibit seismogenic damage expand our knowledge of temporal and spatial distribution of earthquakes, afford independent examination of historical accounts, provide information on local earthquake intensities and enable the delineation of macroseismic zones. They also illustrate what might happen in future earthquakes. In order to recover this information, we should be able to distinguish earthquake damage from anthropogenic damage and from other natural processes of wear and tear. The present paper reviews several types of damage that can be attributed with high certainty to earthquakes and discusses associated caveats. In the rare cases, where faults intersect with archaeological sites, offset structures enable precise determination of sense and size of slip, and constrain its time. Among the characteristic off-fault damage types, I consider horizontal shifting of large building blocks, downward sliding of one or several blocks from masonry arches, collapse of heavy, stably-built walls, chipping of corners of building blocks, and aligned falling of walls and columns. Other damage features are less conclusive and require additional evidence, e.g., fractures that cut across several structures, leaning walls and columns, warps and bulges in walls. Circumstantial evidence for catastrophic earthquake-related destruction includes contemporaneous damage in many sites in the same area, absence of weapons or other anthropogenic damage, stratigraphic data on collapse of walls and ceilings onto floors and other living horizons and burial of valuable artifacts, as well as associated geological palaeoseismic phenomena such as liquefaction, land- and rock-slides, and fault ruptures. Additional support may be found in reliable historical accounts. Special care must be taken in order to avoid circular reasoning by maintaining the independence of data acquisition methods.

  10. DEMETER Observations of Equatorial Plasma Depletions and Related Ionospheric Phenomena

    NASA Astrophysics Data System (ADS)

    Berthelier, J.; Malingre, M.; Pfaff, R.; Jasperse, J.; Parrot, M.

    2008-12-01

    DEMETER, the first micro-satellite of the CNES MYRIAD program, was launched from Baikonour on June 29, 2004 on a nearly circular, quasi helio-synchronous polar orbit at ~ 715 km altitude. The DEMETER mission focuses primarily on the search for a possible coupling between seismic activity and ionospheric disturbances as well as on the effects of natural phenomena such as tropospheric thunderstorms and man-made activities on the ionosphere. The scientific payload provides fairly complete measurements of the ionospheric plasma, energetic particles above ~ 70 keV, and plasma waves, up to 20 kHz for the magnetic and 3.3 MHz for the electric components. Several studies related to space weather and ionospheric physics have been conducted over the past years. Following a brief description of the payload and the satellite modes of operation, this presentation will focus on a set of results that provide a new insight into the physics of instabilities in the night-time equatorial ionosphere. The observations were performed during the major magnetic storm of November 2004. Deep plasma depletions were observed on several night-time passes at low latitudes characterized by the decrease of the plasma density by nearly 3 orders of magnitude relative to the undisturbed plasma, and a significant abundance of molecular ions. These features can be best interpreted as resulting from the rise of the F-layer above the satellite altitude over an extended region of the ionosphere. In one of the passes, DEMETER was operated in the Burst mode and the corresponding high resolution data allowed for the discovery of two unexpected phenomena. The first one is the existence of high intensity monochromatic wave packets at the LH frequency that develop during the decay phase of intense bursts of broadband LH turbulence. The broadband LH turbulence is triggered by whistlers emitted by lightning from atmospheric thunderstorms beneath the satellite. The second unexpected feature is the detection of a

  11. Earthquake!

    ERIC Educational Resources Information Center

    Hernandez, Hildo

    2000-01-01

    Examines the types of damage experienced by California State University at Northridge during the 1994 earthquake and what lessons were learned in handling this emergency are discussed. The problem of loose asbestos is addressed. (GR)

  12. Relating stick-slip friction experiments to earthquake source parameters

    McGarr, Arthur F.

    2012-01-01

    Analytical results for parameters, such as static stress drop, for stick-slip friction experiments, with arbitrary input parameters, can be determined by solving an energy-balance equation. These results can then be related to a given earthquake based on its seismic moment and the maximum slip within its rupture zone, assuming that the rupture process entails the same physics as stick-slip friction. This analysis yields overshoots and ratios of apparent stress to static stress drop of about 0.25. The inferred earthquake source parameters static stress drop, apparent stress, slip rate, and radiated energy are robust inasmuch as they are largely independent of the experimental parameters used in their estimation. Instead, these earthquake parameters depend on C, the ratio of maximum slip to the cube root of the seismic moment. C is controlled by the normal stress applied to the rupture plane and the difference between the static and dynamic coefficients of friction. Estimating yield stress and seismic efficiency using the same procedure is only possible when the actual static and dynamic coefficients of friction are known within the earthquake rupture zone.

  13. The 1868 Hayward fault, California, earthquake: Implications for earthquake scaling relations on partially creeping faults

    Hough, Susan E.; Martin, Stacey

    2015-01-01

    The 21 October 1868 Hayward, California, earthquake is among the best-characterized historical earthquakes in California. In contrast to many other moderate-to-large historical events, the causative fault is clearly established. Published magnitude estimates have been fairly consistent, ranging from 6.8 to 7.2, with 95% confidence limits including values as low as 6.5. The magnitude is of particular importance for assessment of seismic hazard associated with the Hayward fault and, more generally, to develop appropriate magnitude–rupture length scaling relations for partially creeping faults. The recent reevaluation of archival accounts by Boatwright and Bundock (2008), together with the growing volume of well-calibrated intensity data from the U.S. Geological Survey “Did You Feel It?” (DYFI) system, provide an opportunity to revisit and refine the magnitude estimate. In this study, we estimate the magnitude using two different methods that use DYFI data as calibration. Both approaches yield preferred magnitude estimates of 6.3–6.6, assuming an average stress drop. A consideration of data limitations associated with settlement patterns increases the range to 6.3–6.7, with a preferred estimate of 6.5. Although magnitude estimates for historical earthquakes are inevitably uncertain, we conclude that, at a minimum, a lower-magnitude estimate represents a credible alternative interpretation of available data. We further discuss implications of our results for probabilistic seismic-hazard assessment from partially creeping faults.

  14. EUV Dimmings as a Diagnostic of CMEs and Related Phenomena

    NASA Technical Reports Server (NTRS)

    Thompson, Barbara J.; Mays, M. Leila; Webb, David F.; West, Matthew J.

    2012-01-01

    Large-scale coronal EUV dimmings, developing on timescaJes of minutes to hours in association with a flare or filament eruption, are known to exhibit a high correlation with coronal mass ejections. While most observations indicate that the decrease in emission in a dimming is due, at least in part, to a density decrease, a complete understanding requires us to examine at least four mechanisms that have been observed to cause darkened regions in the corona: 1) mass loss, 2) cooling, 3) heating, and 4) absorption/obscuration. Recent advances in automatic detection, observations with improved cadence and resolution, multi-viewpoint imaging, and spectroscopic studies have continued to shed light on dimming formation, evolution, and recovery. However, there are still some outstanding questions, including 1) Why do some CMEs show dimming and some do not? 2) What determines the location of a dimming? 3) What determines the temporal evolution of a dimming? 4) How does the post-eruption dimming connect to the ICME? 5) What is the relationship between dimmings and other CME-associated phenomena? The talk will emphasize the different formation mechanisms of dimmings and their relationship to CMEs and CME-associated phenomena.

  15. Seismic, structural, and individual factors associated with earthquake related injury

    PubMed Central

    Peek-Asa, C; Ramirez, M; Seligson, H; Shoaf, K

    2003-01-01

    Background: Earthquakes cause thousands of deaths worldwide every year, and systematic study of the causes of these deaths can lead to their prevention. Few studies have examined how multiple types of risk factors are related to physical injury during an earthquake. Methods: A population based case-control study was conducted to examine how individual characteristics, building characteristics, and seismic features of the 1994 Northridge, California, earthquake contributed to physical injury. Cases included fatal and hospital-admitted injuries caused by the earthquake. Controls were drawn from a population based phone survey of county residents. Cases were individually matched to two sets of controls: one matched by age and gender and one matched by location at the time of the earthquake. Results: Individuals over age 65 had 2.9 times the risk of injury as younger people (95% confidence interval (CI) 1.2 to 7.4) and women had a 2.4 times greater risk than men (95% CI 1.2 to 5.1). Location in multiple unit residential and commercial structures each led to increased injury risk compared with single unit residential structures, but the exact estimate varied depending on the control group used. With every increase in ground motion of 10%g, injury risk increased 2.2 times (95% CI 1.6 to 3.3). Conclusions: Controlling for other factors, it was found that individual, building, and seismic characteristics were independently predictive of increased injury risk. Prevention and preparedness efforts should focus on each of these as potential points of intervention. PMID:12642562

  16. INVESTIGATIVE RESEARCH PROJECTS RELATED TO THE TOHOKU EARTHQUAKE (THE GREAT EAST JAPAN EARTHQUAKE) CONDUCTED IN FUKUSHIMA

    PubMed Central

    YAMAMOTO, TOSHIYUKI; HASHIMOTO, YASUHIRO; YOSHIDA, MASAYUKI; OHNO, KIKUO; OHTO, HITOSHI; ABE, MASAFUMI

    2015-01-01

    ABSTRACT Backgrounds: On March 11th 2011, the Tohoku region of Japan was struck by catastrophic disasters. Thousands of people were killed due to a magnitude 9.0 earthquake and its subsequent tsunami. Furthermore, a serious nuclear crisis occurred in Fukushima Prefecture as a result of the disasters, and an emergency evacuation was ordered to people living near the nuclear power plants. There was a lot of anxiety regarding lost families as well as the influences of radioactivity on the health of people and their children. Based on these urgent and uncertain situations, a number of research projects were developed at many institutes both inside and outside Fukushima. Methods: We herein report the investigative research projects related to the Tohoku Earthquake (The Great East Japan Earthquake) conducted after the disasters. The research projects were reviewed by the Institutional Review Board in Fukushima Medical University during the two years following the disasters. The research projects conducted in universities other than Fukushima Medical University were also examined using questionnaire analysis. Results: Among the research projects conducted in Fukushima Medical University (n=424), 7% (n=32) were disaster-related investigative research. The mean duration planned to pursue the projects was 25.5 months. Among these projects, those focusing on the health of Fukushima citizens were most common (n=9), followed by the influence of chronic exposure of radiation on chronic inflammatory disorders (n=6), and the mental health of Fukushima citizens (n=5). They were carefully reviewed for the purpose, suitability, and necessity from ethical as well as scientific viewpoints. The majority of the research projects focused on the effects of the Tohoku Earthquake and/or chronic exposure to low-dose radioactivity on the health of children and pregnant women, as well as on various disorders, such as mental health and chronic inflammatory diseases. On the other hand, among 58

  17. INVESTIGATIVE RESEARCH PROJECTS RELATED TO THE TOHOKU EARTHQUAKE (THE GREAT EAST JAPAN EARTHQUAKE) CONDUCTED IN FUKUSHIMA.

    PubMed

    Yamamoto, Toshiyuki; Hashimoto, Yasuhiro; Yoshida, Masayuki; Ohno, Kikuo; Ohto, Hitoshi; Abe, Masafumi

    2015-01-01

    On March 11(th) 2011, the Tohoku region of Japan was struck by catastrophic disasters. Thousands of people were killed due to a magnitude 9.0 earthquake and its subsequent tsunami. Furthermore, a serious nuclear crisis occurred in Fukushima Prefecture as a result of the disasters, and an emergency evacuation was ordered to people living near the nuclear power plants. There was a lot of anxiety regarding lost families as well as the influences of radioactivity on the health of people and their children. Based on these urgent and uncertain situations, a number of research projects were developed at many institutes both inside and outside Fukushima. We herein report the investigative research projects related to the Tohoku Earthquake (The Great East Japan Earthquake) conducted after the disasters. The research projects were reviewed by the Institutional Review Board in Fukushima Medical University during the two years following the disasters. The research projects conducted in universities other than Fukushima Medical University were also examined using questionnaire analysis. Among the research projects conducted in Fukushima Medical University (n=424), 7% (n=32) were disaster-related investigative research. The mean duration planned to pursue the projects was 25.5 months. Among these projects, those focusing on the health of Fukushima citizens were most common (n=9), followed by the influence of chronic exposure of radiation on chronic inflammatory disorders (n=6), and the mental health of Fukushima citizens (n=5). They were carefully reviewed for the purpose, suitability, and necessity from ethical as well as scientific viewpoints. The majority of the research projects focused on the effects of the Tohoku Earthquake and/or chronic exposure to low-dose radioactivity on the health of children and pregnant women, as well as on various disorders, such as mental health and chronic inflammatory diseases. On the other hand, among 58 projects we collected from 22

  18. The myth of interconnected plastids and related phenomena.

    PubMed

    Schattat, Martin H; Barton, Kiah A; Mathur, Jaideep

    2015-01-01

    Studies spread over nearly two and a half centuries have identified the primary plastid in autotrophic algae and plants as a pleomorphic, multifunctional organelle comprising of a double-membrane envelope enclosing an organization of internal membranes submerged in a watery stroma. All plastid units have been observed extending and retracting thin stroma-filled tubules named stromules sporadically. Observations on living plant cells often convey the impression that stromules connect two or more independent plastids with each other. When photo-bleaching techniques were used to suggest that macromolecules such as the green fluorescent protein could flow between already interconnected plastids, for many people this impression changed to conviction. However, it was noticed only recently that the concept of protein flow between plastids rests solely on the words "interconnected plastids" for which details have never been provided. We have critically reviewed botanical literature dating back to the 1880s for understanding this term and the phenomena that have become associated with it. We find that while meticulously detailed ontogenic studies spanning nearly 150 years have established the plastid as a singular unit organelle, there is no experimental support for the idea that interconnected plastids exist under normal conditions of growth and development. In this review, while we consider several possibilities that might allow a single elongated plastid to be misinterpreted as two or more interconnected plastids, our final conclusion is that the concept of direct protein flow between plastids is based on an unfounded assumption.

  19. Texture related unusual phenomena in electrodeposition and vapor deposition

    NASA Astrophysics Data System (ADS)

    Lee, D. N.; Han, H. N.

    2015-04-01

    The tensile strength of electrodeposits generally decreases with increasing bath temperature because the grain size increases and the dislocation density decreases with increasing bath temperature. Therefore, discontinuities observed in the tensile strength vs. bath temperature curves in electrodeposition of copper are unusual. The tensile strength of electrodeposits generally increases with increasing cathode current density because the rate of nucleation in electrodeposits increases with increasing current density, which in turn gives rise to a decrease in the grain size and in turn an increase in the strength. Therefore, a decrease in the tensile strength of copper electrodeposits at a high current density is unusual. The grain size of vapor deposits is expected to decrease with decreasing substrate temperature. However, rf sputtered Co-Cr deposits showed that deposits formed on water-cooled polyimide substrates had a larger grain size than deposits formed on polyimide substrates at 200 °C. These unusual phenomena can be explained by the preferred growth model for deposition texture evolution.

  20. Earthquake and tsunami forecasts: Relation of slow slip events to subsequent earthquake rupture

    PubMed Central

    Dixon, Timothy H.; Jiang, Yan; Malservisi, Rocco; McCaffrey, Robert; Voss, Nicholas; Protti, Marino; Gonzalez, Victor

    2014-01-01

    The 5 September 2012 Mw 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr–Coulomb failure stress were probably too small to trigger the earthquake. Because many SSEs have occurred without subsequent rupture, their individual predictive value is limited, but taken together they released a significant amount of accumulated interseismic strain before the earthquake, effectively defining the area of subsequent seismic rupture (rupture did not occur where slow slip was common). Because earthquake magnitude depends on rupture area, this has important implications for earthquake hazard assessment. Specifically, if this behavior is representative of future earthquake cycles and other subduction zones, it implies that monitoring SSEs, including shallow up-dip events that lie offshore, could lead to accurate forecasts of earthquake magnitude and tsunami potential. PMID:25404327

  1. Earthquake and tsunami forecasts: relation of slow slip events to subsequent earthquake rupture.

    PubMed

    Dixon, Timothy H; Jiang, Yan; Malservisi, Rocco; McCaffrey, Robert; Voss, Nicholas; Protti, Marino; Gonzalez, Victor

    2014-12-02

    The 5 September 2012 M(w) 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr-Coulomb failure stress were probably too small to trigger the earthquake. Because many SSEs have occurred without subsequent rupture, their individual predictive value is limited, but taken together they released a significant amount of accumulated interseismic strain before the earthquake, effectively defining the area of subsequent seismic rupture (rupture did not occur where slow slip was common). Because earthquake magnitude depends on rupture area, this has important implications for earthquake hazard assessment. Specifically, if this behavior is representative of future earthquake cycles and other subduction zones, it implies that monitoring SSEs, including shallow up-dip events that lie offshore, could lead to accurate forecasts of earthquake magnitude and tsunami potential.

  2. Electrocardiographic features of patients with earthquake related posttraumatic stress disorder

    PubMed Central

    İlhan, Erkan; Kaplan, Abdullah; Güvenç, Tolga Sinan; Biteker, Murat; Karabulut, Evindar; Işıklı, Serhan

    2013-01-01

    AIM: To analyze electrocardiographic features of patients diagnosed with posttraumatic stress disorder (PTSD) after the Van-Erciş earthquake, with a shock measuring 7.2 on the Richter scale that took place in Turkey in October 2011. METHODS: Surface electrocardiograms of 12 patients with PTSD admitted to Van Erciş State Hospital (Van, Turkey) from February 2012 to May 2012 were examined. Psychiatric interviews of the sex and age matched control subjects, who had experienced the earthquake, confirmed the absence of any known diagnosable psychiatric conditions in the control group. RESULTS: A wide range of electrocardiogram (ECG) parameters, such as P-wave dispersion, QT dispersion, QT interval, Tpeak to Tend interval, intrinsicoid deflection durations and other traditional parameters were similar in both groups. There was no one with an abnormal P wave axis, short or long PR interval, long or short QT interval, negative T wave in lateral leads, abnormal T wave axis, abnormal left or right intrinsicoid deflection duration, low voltage, left bundle branch block, right bundle branch block, left posterior hemiblock, left or right axis deviation, left ventricular hypertrophy, right or left atrial enlargement and pathological q(Q) wave in either group. CONCLUSION: The study showed no direct effect of earthquake related PTSD on surface ECG in young patients. So, we propose that PTSD has no direct effect on surface ECG but may cause electrocardiographic changes indirectly by triggering atherosclerosis and/or contributing to the ongoing atherosclerotic process. PMID:23538549

  3. Precise relative locations for earthquakes in the northeast Pacific region

    DOE PAGES

    Cleveland, K. Michael; VanDeMark, Thomas F.; Ammon, Charles J.

    2015-10-09

    We report that double-difference methods applied to cross-correlation measured Rayleigh wave time shifts are an effective tool to improve epicentroid locations and relative origin time shifts in remote regions. We apply these methods to seismicity offshore of southwestern Canada and the U.S. Pacific Northwest, occurring along the boundaries of the Pacific and Juan de Fuca (including the Explorer Plate and Gorda Block) Plates. The Blanco, Mendocino, Revere-Dellwood, Nootka, and Sovanco fracture zones host the majority of this seismicity, largely consisting of strike-slip earthquakes. The Explorer, Juan de Fuca, and Gorda spreading ridges join these fracture zones and host normal faultingmore » earthquakes. Our results show that at least the moderate-magnitude activity clusters along fault strike, supporting suggestions of large variations in seismic coupling along oceanic transform faults. Our improved relative locations corroborate earlier interpretations of the internal deformation in the Explorer and Gorda Plates. North of the Explorer Plate, improved locations support models that propose northern extension of the Revere-Dellwood fault. Relocations also support interpretations that favor multiple parallel active faults along the Blanco Transform Fault Zone. Seismicity of the western half of the Blanco appears more scattered and less collinear than the eastern half, possibly related to fault maturity. We use azimuthal variations in the Rayleigh wave cross-correlation amplitude to detect and model rupture directivity for a moderate size earthquake along the eastern Blanco Fault. Lastly, the observations constrain the seismogenic zone geometry and suggest a relatively narrow seismogenic zone width of 2 to 4 km.« less

  4. Physical phenomena related to crystal growth in the space environment

    NASA Technical Reports Server (NTRS)

    Chu, T. L.

    1973-01-01

    The mechanism of crystal growth which may be affected by the space environment was studied. Conclusions as to the relative technical and scientific advantages of crystal growth in space over earth bound growth, without regard to economic advantage, were deduced. It was concluded that the crucibleless technique will most directly demonstrate the unique effects of the greatly reduced gravity in the space environment. Several experiments, including crucibleless crystal growth using solar energy and determination of diffusion coefficients of common dopants in liquid silicon were recommended.

  5. Lightning and related phenomena in thunderstorms and squall lines

    NASA Technical Reports Server (NTRS)

    Rust, W. D.; Taylor, W. L.; Macgorman, D. R.; Brandes, E.; Mazur, V.; Arnold, R.; Marshall, T.; Christian, H.; Goodman, S. J.

    1984-01-01

    During the past few years, cooperative research on storm electricity has yielded the following results of both basic and applied interest: (1) the intracloud to cloud-to-ground flashing ratio can be as great as 40:1; (2) as storm cells in a squall line dissipate, longer flashes become predominant; (3) there are two centers of lightning activity maxima that are vertically separated, the lower maximum at about 5 km and the upper at about 12 km. In addition, (4) storms produce lightning in their upper regions at a high rate; (5) lightning appears to be related in time to convective motions; (6) positive cloud-to-ground flashes occur in the severe stage of storms and in the later, well-developed stage of squall line storms; (7) mesoscale convective complexes have been observed to have cloud-to-ground flashing rates of more than 48/min; and (8) the electric field in anvils well away from the main storm core (more than 60 km) can be very high, more than 94 kV/m.

  6. Earthquake prediction: the interaction of public policy and science.

    PubMed Central

    Jones, L M

    1996-01-01

    Earthquake prediction research has searched for both informational phenomena, those that provide information about earthquake hazards useful to the public, and causal phenomena, causally related to the physical processes governing failure on a fault, to improve our understanding of those processes. Neither informational nor causal phenomena are a subset of the other. I propose a classification of potential earthquake predictors of informational, causal, and predictive phenomena, where predictors are causal phenomena that provide more accurate assessments of the earthquake hazard than can be gotten from assuming a random distribution. Achieving higher, more accurate probabilities than a random distribution requires much more information about the precursor than just that it is causally related to the earthquake. PMID:11607656

  7. Sensory phenomena related to tics, obsessive-compulsive symptoms, and global functioning in Tourette syndrome.

    PubMed

    Kano, Yukiko; Matsuda, Natsumi; Nonaka, Maiko; Fujio, Miyuki; Kuwabara, Hitoshi; Kono, Toshiaki

    2015-10-01

    Sensory phenomena, including premonitory urges, are experienced by patients with Tourette syndrome (TS) and obsessive-compulsive disorder (OCD). The goal of the present study was to investigate such phenomena related to tics, obsessive-compulsive symptoms (OCS), and global functioning in Japanese patients with TS. Forty-one patients with TS were assessed using the University of São Paulo Sensory Phenomena Scale (USP-SPS), the Premonitory Urge for Tics Scale (PUTS), the Yale Global Tic Severity Scale (YGTSS), the Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS), and the Global Assessment of Functioning (GAF) Scale. USP-SPS and PUTS total scores were significantly correlated with YGTSS total and vocal tics scores. Additionally, both sensory phenomena severity scores were significantly correlated with DY-BOCS total OCS scores. Of the six dimensional OCS scores, the USP-SPS scores were significantly correlated with measures of aggression and sexual/religious dimensions. Finally, the PUTS total scores were significantly and negatively correlated with GAF scores. By assessing premonitory urges and broader sensory phenomena, and by viewing OCS from a dimensional approach, this study provides significant insight into sensory phenomena related to tics, OCS, and global functioning in patients with TS. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Study of the characteristics of seismic signals generated by natural and cultural phenomena. [such as earthquakes, sonic booms, and nuclear explosions

    NASA Technical Reports Server (NTRS)

    Goforth, T. T.; Rasmussen, R. K.

    1974-01-01

    Seismic data recorded at the Tonto Forest Seismological Observatory in Arizona and the Uinta Basin Seismological Observatory in Utah were used to compare the frequency of occurrence, severity, and spectral content of ground motions resulting from earthquakes, and other natural and man-made sources with the motions generated by sonic booms. A search of data recorded at the two observatories yielded a classification of over 180,000 earthquake phase arrivals on the basis of frequency of occurrence versus maximum ground velocity. The majority of the large ground velocities were produced by seismic surface waves from moderate to large earthquakes in the western United States, and particularly along the Pacific Coast of the United States and northern Mexico. A visual analysis of raw film seismogram data over a 3-year period indicates that local and regional seismic events, including quarry blasts, are frequent in occurrence, but do not produce ground motions at the observatories comparable to either the large western United States earthquakes or to sonic booms. Seismic data from the Nevada Test Site nuclear blasts were used to derive magnitude-distance-sonic boom overpressure relations.

  9. The continuous automatic monitoring network installed in Tuscany (Italy) since late 2002, to study earthquake precursory phenomena

    NASA Astrophysics Data System (ADS)

    Pierotti, Lisa; Cioni, Roberto

    2010-05-01

    Since late 2002, a continuous automatic monitoring network (CAMN) was designed, built and installed in Tuscany (Italy), in order to investigate and define the geochemical response of the aquifers to the local seismic activity. The purpose of the investigation was to identify eventual earthquake precursors. The CAMN is constituted by two groups of five measurement stations each. A first group has been installed in the Serchio and Magra graben (Garfagnana and Lunigiana Valleys, Northern Tuscany), while the second one, in the area of Mt. Amiata (Southern Tuscany), an extinct volcano. Garfagnana, Lunigiana and Mt. Amiata regions belong to the inner zone of the Northern Apennine fold-and-thrust belt. This zone has been involved in the post-collision extensional tectonics since the Upper Miocene-Pliocene. Such tectonic activity has produced horst and graben structures oriented from N-S to NW-SE that are transferred by NE-SW system. Both Garfagnana (Serchio graben) and Lunigiana (Magra graben) belong to the most inner sector of the belt where the seismic sources, responsible for the strongest earthquakes of the northern Apennine, are located (e.g. the M=6.5 earthquake of September 1920). The extensional processes in southern Tuscany have been accompanied by magmatic activity since the Upper Miocene, developing effusive and intrusive products traditionally attributed to the so-called Tuscan Magmatic Province. Mt. Amiata, whose magmatic activity ceased about 0.3 M.y. ago, belongs to the extensive Tyrrhenian sector that is characterized by high heat flow and crustal thinning. The whole zone is characterized by wide-spread but moderate seismicity (the maximum recorded magnitude has been 5.1 with epicentre in Piancastagnaio, 1919). The extensional regime in both the Garfagnana-Lunigiana and Mt. Amiata area is confirmed by the focal mechanisms of recent earthquakes. An essential phase of the monitoring activities has been the selection of suitable sites for the installation of

  10. Multi-Sensor Observations of Earthquake Related Atmospheric Signals over Major Geohazard Validation Sites

    NASA Technical Reports Server (NTRS)

    Ouzounov, D.; Pulinets, S.; Davindenko, D.; Hattori, K.; Kafatos, M.; Taylor, P.

    2012-01-01

    We are conducting a scientific validation study involving multi-sensor observations in our investigation of phenomena preceding major earthquakes. Our approach is based on a systematic analysis of several atmospheric and environmental parameters, which we found, are associated with the earthquakes, namely: thermal infrared radiation, outgoing long-wavelength radiation, ionospheric electron density, and atmospheric temperature and humidity. For first time we applied this approach to selected GEOSS sites prone to earthquakes or volcanoes. This provides a new opportunity to cross validate our results with the dense networks of in-situ and space measurements. We investigated two different seismic aspects, first the sites with recent large earthquakes, viz.- Tohoku-oki (M9, 2011, Japan) and Emilia region (M5.9, 2012,N. Italy). Our retrospective analysis of satellite data has shown the presence of anomalies in the atmosphere. Second, we did a retrospective analysis to check the re-occurrence of similar anomalous behavior in atmosphere/ionosphere over three regions with distinct geological settings and high seismicity: Taiwan, Japan and Kamchatka, which include 40 major earthquakes (M>5.9) for the period of 2005-2009. We found anomalous behavior before all of these events with no false negatives; false positives were less then 10%. Our initial results suggest that multi-instrument space-borne and ground observations show a systematic appearance of atmospheric anomalies near the epicentral area that could be explained by a coupling between the observed physical parameters and earthquake preparation processes.

  11. Earthquakes

    MedlinePlus

    ... Situations Food and Water People with Special Needs PSAs and Podcasts Extreme Heat About Extreme Heat Protecting ... to Stay Cool Missouri Cooling Centers Extreme Heat PSAs Related Links MMWR Bibliography Floods Flood Readiness Personal ...

  12. Cascading hazards: Understanding triggering relations between wet tropical cyclones, landslides, and earthquakes

    NASA Astrophysics Data System (ADS)

    Wdowinski, S.; Peng, Z.; Ferrier, K.; Lin, C. H.; Hsu, Y. J.; Shyu, J. B. H.

    2017-12-01

    Earthquakes, landslides, and tropical cyclones are extreme hazards that pose significant threats to human life and property. Some of the couplings between these hazards are well known. For example, sudden, widespread landsliding can be triggered by large earthquakes and by extreme rainfall events like tropical cyclones. Recent studies have also shown that earthquakes can be triggered by erosional unloading over 100-year timescales. In a NASA supported project, titled "Cascading hazards: Understanding triggering relations between wet tropical cyclones, landslides, and earthquake", we study triggering relations between these hazard types. The project focuses on such triggering relations in Taiwan, which is subjected to very wet tropical storms, landslides, and earthquakes. One example for such triggering relations is the 2009 Morakot typhoon, which was the wettest recorded typhoon in Taiwan (2850 mm of rain in 100 hours). The typhoon caused widespread flooding and triggered more than 20,000 landslides, including the devastating Hsiaolin landslide. Six months later, the same area was hit by the 2010 M=6.4 Jiashian earthquake near Kaohsiung city, which added to the infrastructure damage induced by the typhoon and the landslides. Preliminary analysis of temporal relations between main-shock earthquakes and the six wettest typhoons in Taiwan's past 50 years reveals similar temporal relations between M≥5 events and wet typhoons. Future work in the project will include remote sensing analysis of landsliding, seismic and geodetic monitoring of landslides, detection of microseismicity and tremor activities, and mechanical modeling of crustal stress changes due to surface unloading.

  13. Analog earthquakes

    SciT

    Hofmann, R.B.

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed.more » A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.« less

  14. Analysis and selection of magnitude relations for the Working Group on Utah Earthquake Probabilities

    Duross, Christopher; Olig, Susan; Schwartz, David

    2015-01-01

    Prior to calculating time-independent and -dependent earthquake probabilities for faults in the Wasatch Front region, the Working Group on Utah Earthquake Probabilities (WGUEP) updated a seismic-source model for the region (Wong and others, 2014) and evaluated 19 historical regressions on earthquake magnitude (M). These regressions relate M to fault parameters for historical surface-faulting earthquakes, including linear fault length (e.g., surface-rupture length [SRL] or segment length), average displacement, maximum displacement, rupture area, seismic moment (Mo ), and slip rate. These regressions show that significant epistemic uncertainties complicate the determination of characteristic magnitude for fault sources in the Basin and Range Province (BRP). For example, we found that M estimates (as a function of SRL) span about 0.3–0.4 units (figure 1) owing to differences in the fault parameter used; age, quality, and size of historical earthquake databases; and fault type and region considered.

  15. Anomalous phenomena in Schumann resonance band observed in China before the 2011 magnitude 9.0 Tohoku-Oki earthquake in Japan

    NASA Astrophysics Data System (ADS)

    Zhou, Hongjuan; Zhou, Zhiquan; Qiao, Xiaolin; Yu, Haiyan

    2013-12-01

    anomalous phenomena in the Schumann resonance (SR) band, possibly associated with the Tohoku-Oki earthquake (EQ), are studied based on the ELF observations at two stations in China. The anomaly appeared on 8 March, 3 days prior to the main shock, and was characterized by an increase in the intensity at frequencies from the first mode to the fourth mode in both magnetic field components, different from the observations in Japan before large EQs in Taiwan. The abnormal behaviors of the north-south and east-west magnetic field components primarily appeared at 0000-0900 UT and 0200-0900 UT on 8 March, respectively. The finite difference time domain numerical method is applied to model the impact of seismic process on the ELF radio propagation. A partially uniform knee model of the vertical conductivity profile suggested by V. C. Mushtak is used to model the day-night asymmetric Earth-ionosphere cavity, and a locally EQ-induced disturbance model of the atmospheric conductivity is introduced. The atmospheric conductivity is assumed to increase around the epicenter according to the localized enhancement of total electron content in the ionosphere. It is concluded that the SR anomalous phenomena before the Tohoku-Oki EQ have much to do with the excited sources located at South America and Asia and also with the localized distribution of the disturbed conductivity. This work is a further confirmation of the relationship of SR anomalies with large EQs and has further concluded that the distortions in the SR band before large EQs may be caused by the irregularities located over the shock epicenter in the Earth-ionosphere cavity by numerical method.

  16. 30 CFR 250.192 - What reports and statistics must I submit relating to a hurricane, earthquake, or other natural...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... relating to a hurricane, earthquake, or other natural occurrence? 250.192 Section 250.192 Mineral Resources... What reports and statistics must I submit relating to a hurricane, earthquake, or other natural..., such as a hurricane, a tropical storm, or an earthquake. Statistics include facilities and rigs...

  17. 30 CFR 250.192 - What reports and statistics must I submit relating to a hurricane, earthquake, or other natural...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... relating to a hurricane, earthquake, or other natural occurrence? 250.192 Section 250.192 Mineral Resources... What reports and statistics must I submit relating to a hurricane, earthquake, or other natural..., such as a hurricane, a tropical storm, or an earthquake. Statistics include facilities and rigs...

  18. 30 CFR 250.192 - What reports and statistics must I submit relating to a hurricane, earthquake, or other natural...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... relating to a hurricane, earthquake, or other natural occurrence? 250.192 Section 250.192 Mineral Resources... Requirements § 250.192 What reports and statistics must I submit relating to a hurricane, earthquake, or other... occurrence, such as a hurricane, a tropical storm, or an earthquake. Statistics include facilities and rigs...

  19. 30 CFR 250.192 - What reports and statistics must I submit relating to a hurricane, earthquake, or other natural...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... relating to a hurricane, earthquake, or other natural occurrence? 250.192 Section 250.192 Mineral Resources... What reports and statistics must I submit relating to a hurricane, earthquake, or other natural..., such as a hurricane, a tropical storm, or an earthquake. Statistics include facilities and rigs...

  20. Theoretical and experimental studies of space-related plasma wave propagation and resonance phenomena

    NASA Technical Reports Server (NTRS)

    Crawford, F. W.

    1975-01-01

    A ten year summary was given of university research on the nature and characteristics of space related plasma resonance phenomena, whistler propagation in laboratory plasmas, and theoretical and experimental studies of plasma wave propagation. Data are also given on long delayed echoes, low frequency instabilities, ionospheric heating, and backscatter, and pulse propagation. A list is included of all conference papers, publications, and reports resulting from the study.

  1. Precise Relative Earthquake Depth Determination Using Array Processing Techniques

    NASA Astrophysics Data System (ADS)

    Florez, M. A.; Prieto, G. A.

    2014-12-01

    The mechanism for intermediate depth and deep earthquakes is still under debate. The temperatures and pressures are above the point where ordinary fractures ought to occur. Key to constraining this mechanism is the precise determination of hypocentral depth. It is well known that using depth phases allows for significant improvement in event depth determination, however routinely and systematically picking such phases for teleseismic or regional arrivals is problematic due to poor signal-to-noise ratios around the pP and sP phases. To overcome this limitation we have taken advantage of the additional information carried by seismic arrays. We have used beamforming and velocity spectral analysis techniques to precise measure pP-P and sP-P differential travel times. These techniques are further extended to achieve subsample accuracy and to allow for events where the signal-to-noise ratio is close to or even less than 1.0. The individual estimates obtained at different subarrays for a pair of earthquakes can be combined using a double-difference technique in order to precisely map seismicity in regions where it is tightly clustered. We illustrate these methods using data from the recent M 7.9 Alaska earthquake and its aftershocks, as well as data from the Bucaramanga nest in northern South America, arguably the densest and most active intermediate-depth earthquake nest in the world.

  2. [Family function and depression in relatives of earthquake victims: a survey conducted one year after China's Wenchuan Earthquake].

    PubMed

    Hu, Xiao-Lin; Li, Xiao-Lin; Jiang, Xiao-Lian; Li, Rong; Dou, Xin-Man

    2012-10-01

    The Wenchuan Earthquake that hit Sichuan, China in 2008 not only caused huge losses in terms of human life and economic damage. It also caused psychological trauma in survivors, especially those who had lost relatives and close friends (bereaved). In the aftermath of earthquakes, bereaved individuals require family and spiritual renewal in addition to material assistance. This study investigated the status of and relationship between family function and depression in bereaved individuals living in areas devastated by the Wenchuan Earthquake. Results provide baseline information for post-disaster family reconstruction. This cross-sectional study surveyed 264 qualified bereaved individuals who lived in an area hard hit by the Wenchuan Earthquake. Face-to-face interviews were administered based on the family APGAR(adaptation, partnership, growth, affection, resolve) index and Hamilton depression (HAMD) scale. The mean family function score for participants was 6.52 ± 2.65. Results for half (50.0%) of participants indicated "good" family function. Results indicated marital status, family structure and status of having another baby as factors that significantly influence family function (p < .05). Participants' mean depression score was 40.41 ± 9.35, with all (100%) of participants demonstrating symptoms of depression. The 5 most prevalent depressive symptoms were: depressed mood, decreased interest in work, mental anxiety, diminished capacity and agitation. Results showed marital status, leisure frequency, economic status, and having another baby as factors that significantly influenced family function (p < .05). A Pearson's correlation analysis indicated no significant relationship between level of depression and family function (p >.05). Family functions of the bereaved living in areas hard hit by the Wenchuan Earthquake were all undermined to varying degrees. Although participants all exhibited depressive symptoms, this study found no affect of such symptoms on

  3. Attention bias in earthquake-exposed survivors: an event-related potential study.

    PubMed

    Zhang, Yan; Kong, Fanchang; Han, Li; Najam Ul Hasan, Abbasi; Chen, Hong

    2014-12-01

    The Chinese Wenchuan earthquake, which happened on the 28th of May in 2008, may leave deep invisible scars in individuals. China has a large number of children and adolescents, who tend to be most vulnerable because they are in an early stage of human development and possible post-traumatic psychological distress may have a life-long consequence. Trauma survivors without post-traumatic stress disorder (PTSD) have received little attention in previous studies, especially in event-related potential (ERP) studies. We compared the attention bias to threat stimuli between the earthquake-exposed group and the control group in a masked version of the dot probe task. The target probe presented at the same space location consistent with earthquake-related words was the congruent trial, while in the space location of neutral words was the incongruent trial. Thirteen earthquake-exposed middle school students without PTSD and 13 matched controls were included in this investigation. The earthquake-exposed group showed significantly faster RTs to congruent trials than to incongruent trials. The earthquake-exposed group produced significantly shorter C1 and P1 latencies and larger C1, P1 and P2 amplitudes than the control group. In particular, enhanced P1 amplitude to threat stimuli was observed in the earthquake-exposed group. These findings are in agreement with the prediction that earthquake-exposed survivors have an attention bias to threat stimuli. The traumatic event had a much greater effect on earthquake-exposed survivors even if they showed no PTSD symptoms than individuals in the controls. These results will provide neurobiological evidences for effective intervention and prevention to post-traumatic mental problems. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Temporal variations of radon in soil related to earthquakes.

    PubMed

    Planinić, J; Radolić, V; Lazanin, Z

    2001-08-01

    A radon detector with LR-115 nuclear track film was constructed for radon concentration measurements in soil. Temporal radon variations, as well as the barometric pressure, precipitation and temperature were measured for two years. Negative correlation between radon concentration in soil and barometric pressure was found. For some of the recorded earthquakes that occurred during the observation period, soil radon anomalies may be noticed one month before the quakes.

  5. Primate empathy: three factors and their combinations for empathy-related phenomena.

    PubMed

    Yamamoto, Shinya

    2017-05-01

    Empathy as a research topic is receiving increasing attention, although there seems some confusion on the definition of empathy across different fields. Frans de Waal (de Waal FBM. Putting the altruism back into altruism: the evolution of empathy. Annu Rev Psychol 2008, 59:279-300. doi:10.1146/annurev.psych.59.103006.093625) used empathy as an umbrella term and proposed a comprehensive model for the evolution of empathy with some of its basic elements in nonhuman animals. In de Waal's model, empathy consists of several layers distinguished by required cognitive levels; the perception-action mechanism plays the core role for connecting ourself and others. Then, human-like empathy such as perspective-taking develops in outer layers according to cognitive sophistication, leading to prosocial acts such as targeted helping. I agree that animals demonstrate many empathy-related phenomena; however, the species differences and the level of cognitive sophistication of the phenomena might be interpreted in another way than this simple linearly developing model. Our recent studies with chimpanzees showed that their perspective-taking ability does not necessarily lead to proactive helping behavior. Herein, as a springboard for further studies, I reorganize the empathy-related phenomena by proposing a combination model instead of the linear development model. This combination model is composed of three organizing factors: matching with others, understanding of others, and prosociality. With these three factors and their combinations, most empathy-related matters can be categorized and mapped to appropriate context; this may be a good first step to discuss the evolution of empathy in relation to the neural connections in human and nonhuman animal brains. I would like to propose further comparative studies, especially from the viewpoint of Homo-Pan (chimpanzee and bonobo) comparison. WIREs Cogn Sci 2017, 8:e1431. doi: 10.1002/wcs.1431 For further resources related to this article

  6. An improved data integration algorithm to constrain the 3D displacement field induced by fast deformation phenomena tested on the Napa Valley earthquake

    NASA Astrophysics Data System (ADS)

    Polcari, Marco; Fernández, José; Albano, Matteo; Bignami, Christian; Palano, Mimmo; Stramondo, Salvatore

    2017-12-01

    In this work, we propose an improved algorithm to constrain the 3D ground displacement field induced by fast surface deformations due to earthquakes or landslides. Based on the integration of different data, we estimate the three displacement components by solving a function minimization problem from the Bayes theory. We exploit the outcomes from SAR Interferometry (InSAR), Global Positioning System (GNSS) and Multiple Aperture Interferometry (MAI) to retrieve the 3D surface displacement field. Any other source of information can be added to the processing chain in a simple way, being the algorithm computationally efficient. Furthermore, we use the intensity Pixel Offset Tracking (POT) to locate the discontinuity produced on the surface by a sudden deformation phenomenon and then improve the GNSS data interpolation. This approach allows to be independent from other information such as in-situ investigations, tectonic studies or knowledge of the data covariance matrix. We applied such a method to investigate the ground deformation field related to the 2014 Mw 6.0 Napa Valley earthquake, occurred few kilometers from the San Andreas fault system.

  7. Facilitation of intermediate-depth earthquakes by eclogitization-related stresses and H2O

    NASA Astrophysics Data System (ADS)

    Nakajima, J.; Uchida, N.; Hasegawa, A.; Shiina, T.; Hacker, B. R.; Kirby, S. H.

    2012-12-01

    Generation of intermediate-depth earthquakes is an ongoing enigma because high lithostatic pressures render ordinary dry frictional failure unlikely. A popular hypothesis to solve this conundrum is fluid-related embrittlement (e.g., Kirby et al., 1996; Preston et al., 2003), which is known to work even for dehydration reactions with negative volume change (Jung et al., 2004). One consequence of reaction with the negative volume change is the formation of a paired stress field as a result of strain compatibility across the reaction front (Hacker, 1996; Kirby et al., 1996). Here we analyze waveforms of a tiny seismic cluster in the lower crust of the downgoing Pacific plate at a depth of 155 km and propose new evidence in favor of this mechanism: tensional earthquakes lying 1 km above compressional earthquakes, and earthquakes with highly similar waveforms lying on well-defined planes with complementary rupture areas. The tensional stress is interpreted to be caused by the dimensional mismatch between crust transformed to eclogite and underlying untransformed crust, and the earthquakes are interpreted to be facilitated by fluid produced by eclogitization. These observations provide seismic evidence for the dual roles of volume-change related stresses and fluid-related embrittlement as viable processes for nucleating earthquakes in downgoing oceanic lithosphere.

  8. Electromagnetic emission memory phenomena related to LiF ionic crystal deformation

    NASA Astrophysics Data System (ADS)

    Mavromatou, C.; Tombras, G. S.; Ninos, D.; Hadjicontis, V.

    2008-04-01

    During the uniaxial compression of LiF ionic monocrystals, acoustic and electromagnetic emissions (EME) are detected. We observed that when the compression is performed in successive loading, unloading cycles and these emissions are being monitored, no new emissions will occur unless the maximum stress of the previous cycle is exceeded, meaning that the material presents memory characteristics. This is observed not only for the acoustic emission (AE), which is the well known Kaiser effect, but for the EME as well. In other words, the material appears to memorize and reveal the previously maximum stress it suffered while being deformed. The importance of an electromagnetic memory feature of a material can be related to various applications in material science, especially when the detection of AE is not feasible or gives false alert. Such cases may very well be earthquakes' predictive indications, monitoring of mines' stability, imminent landslides, etc.

  9. 10.1142/9781911299660_fmatter years Laser Interaction and Related Plasma Phenomena (lirpp Vol. 13)

    NASA Astrophysics Data System (ADS)

    Hora, Heinrich

    2016-10-01

    When these proceedings of 13th international conference LASER INTERACTION AND RELATED PLASMA PHENOMENA (LIRPP) will be circulated in 1998, it is just 30 years that this conference series began. Professor Miley asked me to present some thoughts at this occasion since I am involved from the beginning to 1991 a director and then as emeritus director. The conferences were in the following years 1969, 1971, 1973, 1976, 1979, 1982, 1985, 1987, 1989, 1991, 1993, 1995 and 1997 and reference to each of the conferences is simply given by the year in brackets...

  10. Believing in paranormal phenomena: relations to asymmetry of body and brain.

    PubMed

    Schulter, Günter; Papousek, Ilona

    2008-01-01

    The goal of this study was to investigate the possible relationship between established measures of body and brain asymmetries and individual differences in paranormal beliefs. In addition to behavioural measures of cerebral laterality, measures of facial features and finger length were taken to calculate body asymmetry scores and indicators of fluctuating asymmetry (average absolute differences between left and right body features). Both the direction and degree of laterality measures were used. In addition to that, quantitative measures of inconsistency of cerebral lateralization were obtained. Results indicated that a stronger belief in paranormal phenomena was associated with fluctuating asymmetry of finger length, and that this aspect of body asymmetry may be related to greater intraindividual variability in the degree of 'atypical' functional lateralization. This intraindividual variability index, in turn, significantly predicted strength of belief in the paranormal. Belief in the paranormal was also higher in women than men and it was negatively correlated with the education level. In sum, these findings suggest that a part of the variance of strength of belief in paranormal phenomena can be explained by patterns of functional hemispheric asymmetry that may be related to perturbations during fetal development.

  11. Scaling Relations of Earthquakes on Inland Active Mega-Fault Systems

    NASA Astrophysics Data System (ADS)

    Murotani, S.; Matsushima, S.; Azuma, T.; Irikura, K.; Kitagawa, S.

    2010-12-01

    Since 2005, The Headquarters for Earthquake Research Promotion (HERP) has been publishing 'National Seismic Hazard Maps for Japan' to provide useful information for disaster prevention countermeasures for the country and local public agencies, as well as promote public awareness of disaster prevention of earthquakes. In the course of making the year 2009 version of the map, which is the commemorate of the tenth anniversary of the settlement of the Comprehensive Basic Policy, the methods to evaluate magnitude of earthquakes, to predict strong ground motion, and to construct underground structure were investigated in the Earthquake Research Committee and its subcommittees. In order to predict the magnitude of earthquakes occurring on mega-fault systems, we examined the scaling relations for mega-fault systems using 11 earthquakes of which source processes were analyzed by waveform inversion and of which surface information was investigated. As a result, we found that the data fit in between the scaling relations of seismic moment and rupture area by Somerville et al. (1999) and Irikura and Miyake (2001). We also found that maximum displacement of surface rupture is two to three times larger than the average slip on the seismic fault and surface fault length is equal to length of the source fault. Furthermore, compiled data of the source fault shows that displacement saturates at 10m when fault length(L) is beyond 100km, L>100km. By assuming the fault width (W) to be 18km in average of inland earthquakes in Japan, and the displacement saturate at 10m for length of more than 100 km, we derived a new scaling relation between source area and seismic moment, S[km^2] = 1.0 x 10^-17 M0 [Nm] for mega-fault systems that seismic moment (M0) exceeds 1.8×10^20 Nm.

  12. Scaling relation between earthquake magnitude and the departure time from P wave similar growth

    Noda, Shunta; Ellsworth, William L.

    2016-01-01

    We introduce a new scaling relation between earthquake magnitude (M) and a characteristic of initial P wave displacement. By examining Japanese K-NET data averaged in bins partitioned by Mw and hypocentral distance, we demonstrate that the P wave displacement briefly displays similar growth at the onset of rupture and that the departure time (Tdp), which is defined as the time of departure from similarity of the absolute displacement after applying a band-pass filter, correlates with the final M in a range of 4.5 ≤ Mw ≤ 7. The scaling relation between Mw and Tdp implies that useful information on the final M can be derived while the event is still in progress because Tdp occurs before the completion of rupture. We conclude that the scaling relation is important not only for earthquake early warning but also for the source physics of earthquakes.

  13. Burst of ULF Electric Field Recorded by DEMETER Possibly Related to the Series of Earthquakes Occurred during the Tsunami Over the Indian Region (P19)

    NASA Astrophysics Data System (ADS)

    Gwal, A. K.; Shrivastava, A.

    2006-11-01

    ak_gwal@yahoo.co.in The scientists have found that the accumulation of tectonic energy is localized in certain places and is not universal. Taking into account this hypothesis the authors have studied the sequence of occurrence rate of the earthquakes (M≥5) in the South-East Asian region, as the chronological data related to the occurrence of earthquakes collected in that region for last five years i.e. from 2001 to 2005 have revealed that the disastrous tsunami events which took place on 26th December, 2004 as an effect of Sumatra earthquake( M=9) have increased the occurrence of earthquake frequency for a longer period (which might be due to adjustment of tectonic plates). Observing these facts i.e. sudden enhancement in occurrence rate of earthquakes, the authors have availed this opportunity to further explore the concept of seismoelectromagnetic-ionospheric phenomena, which still needs a lot of statistical evidences, comprising tremendous amount of data to establish it. In this paper the authors have tried to analyze the chain of observations made and data collected and stored month wise w.e.f. 26th December, 2004 to 31st March, 2005 in the region, using DEMETER satellite. Further, efforts have also been made to provide the statistical analysis of the ionospheric variability caused due to detected electromagnetic burst in ULF frequency ranges in the context of natural variability in order to distinguish the variability introduced by other sources. In brief, it could be concluded that there is possibility of getting the electromagnetic precursors in the ionosphere at different frequency ranges due to excess release of tectonic energy as a result of occurrence rate of the earthquakes in the region.

  14. Analysis of the enhanced negative correlation between electron density and electron temperature related to earthquakes

    NASA Astrophysics Data System (ADS)

    Shen, X. H.; Zhang, X.; Liu, J.; Zhao, S. F.; Yuan, G. P.

    2015-04-01

    Ionospheric perturbations in plasma parameters have been observed before large earthquakes, but the correlation between different parameters has been less studied in previous research. The present study is focused on the relationship between electron density (Ne) and temperature (Te) observed by the DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions) satellite during local nighttime, in which a positive correlation has been revealed near the equator and a weak correlation at mid- and low latitudes over both hemispheres. Based on this normal background analysis, the negative correlation with the lowest percent in all Ne and Te points is studied before and after large earthquakes at mid- and low latitudes. The multiparameter observations exhibited typical synchronous disturbances before the Chile M8.8 earthquake in 2010 and the Pu'er M6.4 in 2007, and Te varied inversely with Ne over the epicentral areas. Moreover, statistical analysis has been done by selecting the orbits at a distance of 1000 km and ±7 days before and after the global earthquakes. Enhanced negative correlation coefficients lower than -0.5 between Ne and Te are found in 42% of points to be connected with earthquakes. The correlation median values at different seismic levels show a clear decrease with earthquakes larger than 7. Finally, the electric-field-coupling model is discussed; furthermore, a digital simulation has been carried out by SAMI2 (Sami2 is Another Model of the Ionosphere), which illustrates that the external electric field in the ionosphere can strengthen the negative correlation in Ne and Te at a lower latitude relative to the disturbed source due to the effects of the geomagnetic field. Although seismic activity is not the only source to cause the inverse Ne-Te variations, the present results demonstrate one possibly useful tool in seismo-electromagnetic anomaly differentiation, and a comprehensive analysis with multiple parameters helps to

  15. High-Dimensional Disorder-Driven Phenomena in Weyl Semimetals, Semiconductors, and Related Systems

    NASA Astrophysics Data System (ADS)

    Syzranov, Sergey V.; Radzihovsky, Leo

    2018-03-01

    It is commonly believed that a noninteracting disordered electronic system can undergo only the Anderson metal-insulator transition. It has been suggested, however, that a broad class of systems can display disorder-driven transitions distinct from Anderson localization that have manifestations in the disorder-averaged density of states, conductivity, and other observables. Such transitions have received particular attention in the context of recently discovered 3D Weyl and Dirac materials but have also been predicted in cold-atom systems with long-range interactions, quantum kicked rotors, and all sufficiently high-dimensional systems. Moreover, such systems exhibit unconventional behavior of Lifshitz tails, energy-level statistics, and ballistic-transport properties. Here, we review recent progress and the status of results on non-Anderson disorder-driven transitions and related phenomena.

  16. Applicability of source scaling relations for crustal earthquakes to estimation of the ground motions of the 2016 Kumamoto earthquake

    NASA Astrophysics Data System (ADS)

    Irikura, Kojiro; Miyakoshi, Ken; Kamae, Katsuhiro; Yoshida, Kunikazu; Somei, Kazuhiro; Kurahashi, Susumu; Miyake, Hiroe

    2017-01-01

    A two-stage scaling relationship of the source parameters for crustal earthquakes in Japan has previously been constructed, in which source parameters obtained from the results of waveform inversion of strong motion data are combined with parameters estimated based on geological and geomorphological surveys. A three-stage scaling relationship was subsequently developed to extend scaling to crustal earthquakes with magnitudes greater than M w 7.4. The effectiveness of these scaling relationships was then examined based on the results of waveform inversion of 18 recent crustal earthquakes ( M w 5.4-6.9) that occurred in Japan since the 1995 Hyogo-ken Nanbu earthquake. The 2016 Kumamoto earthquake, with M w 7.0, was one of the largest earthquakes to occur since dense and accurate strong motion observation networks, such as K-NET and KiK-net, were deployed after the 1995 Hyogo-ken Nanbu earthquake. We examined the applicability of the scaling relationships of the source parameters of crustal earthquakes in Japan to the 2016 Kumamoto earthquake. The rupture area and asperity area were determined based on slip distributions obtained from waveform inversion of the 2016 Kumamoto earthquake observations. We found that the relationship between the rupture area and the seismic moment for the 2016 Kumamoto earthquake follows the second-stage scaling within one standard deviation ( σ = 0.14). The ratio of the asperity area to the rupture area for the 2016 Kumamoto earthquake is nearly the same as ratios previously obtained for crustal earthquakes. Furthermore, we simulated the ground motions of this earthquake using a characterized source model consisting of strong motion generation areas (SMGAs) based on the empirical Green's function (EGF) method. The locations and areas of the SMGAs were determined through comparison between the synthetic ground motions and observed motions. The sizes of the SMGAs were nearly coincident with the asperities with large slip. The synthetic

  17. Groundwater flow pattern and related environmental phenomena in complex geologic setting based on integrated model construction

    NASA Astrophysics Data System (ADS)

    Tóth, Ádám; Havril, Tímea; Simon, Szilvia; Galsa, Attila; Monteiro Santos, Fernando A.; Müller, Imre; Mádl-Szőnyi, Judit

    2016-08-01

    Groundwater flow, driven, controlled and determined by topography, geology and climate, is responsible for several natural surface manifestations and affected by anthropogenic processes. Therefore, flowing groundwater can be regarded as an environmental agent. Numerical simulation of groundwater flow could reveal the flow pattern and explain the observed features. In complex geologic framework, where the geologic-hydrogeologic knowledge is limited, the groundwater flow model could not be constructed based solely on borehole data, but geophysical information could aid the model building. The integrated model construction was presented via the case study of the Tihany Peninsula, Hungary, with the aims of understanding the background and occurrence of groundwater-related environmental phenomena, such as wetlands, surface water-groundwater interaction, slope instability, and revealing the potential effect of anthropogenic activity and climate change. The hydrogeologic model was prepared on the basis of the compiled archive geophysical database and the results of recently performed geophysical measurements complemented with geologic-hydrogeologic data. Derivation of different electrostratigraphic units, revealing fracturing and detecting tectonic elements was achieved by systematically combined electromagnetic geophysical methods. The deduced information can be used as model input for groundwater flow simulation concerning hydrostratigraphy, geometry and boundary conditions. The results of numerical modelling were interpreted on the basis of gravity-driven regional groundwater flow concept and validated by field mapping of groundwater-related phenomena. The 3D model clarified the hydraulic behaviour of the formations, revealed the subsurface hydraulic connection between groundwater and wetlands and displayed the groundwater discharge pattern, as well. The position of wetlands, their vegetation type, discharge features and induced landslides were explained as

  18. Earthquakes and related catastrophic events, Island of Hawaii, November 29, 1975; a preliminary report

    Tilling, Robert I.; Koyanagi, R.Y.; Lipman, P.W.; Lockwood, J.P.; Moore, J.G.; Swanson, D.A.

    1976-01-01

    The largest earthquake in over a century--magnitude 7.2 on the Richter Scale--struck Hawaii the morning of November 29, 1975, at 0448. It was centered about 5 km beneath the Kalapana area on the southeastern coast of the island at 19? 20.1 ' N., long 155? 01.4 ' W.). The earthquake was preceded by numerous foreshocks, the largest of which was a 5.7-magnitude jolt at 0336 the same morning, and was accompanied, or closely followed, by a tsunami seismic sea wave), massive ground movements, hundreds of aftershocks, and a volcanic eruption. The tsunami reached a height of 12.2-14.6 m above sea level on the southeastern coast about 25 km west of the earthquake center, elsewhere generally 8 m or less. The south flank of Kilauea Volcano, which forms the southeastern part of the island, was deformed by dislocations along old and new faults along a 25-km long zone. Downward and seaward fault displacements resulted in widespread subsidence, locally as much as 3.5 m, leaving coconut palms standing in the sea and nearly submerging a small, near-shore island. A brief, small-volume volcanic eruption, triggered by the earthquake and associated ground movements occurred at Kilauea's summit about three-quarters of an hour later. The earthquake, together with the tsunami it generated, locally caused severe property damage in the southeastern part of the island; the tsunami also caused two deaths. Damage from the earthquake and related catastrophic events is estimated by the Hawaii Civil Defense Agency at about $4.1 million. The 1975 Kalapana earthquake and accompanying events represent the latest events in a recurring pattern of behavior for Kilauea. A large earthquake of about the same magnitude, tsunami, subsidence, and eruption occurred at Kilauea in 1868, and a less powerful earthquake and similar related processes are believed to have occurred in 1823. Indeed, the geologic evidence suggests that such events have been repeated many times in Kilauea's past and will continue. The

  19. Charles Darwin's earthquake reports

    NASA Astrophysics Data System (ADS)

    Galiev, Shamil

    2010-05-01

    problems which began to discuss only during the last time. Earthquakes often precede volcanic eruptions. According to Darwin, the earthquake-induced shock may be a common mechanism of the simultaneous eruptions of the volcanoes separated by long distances. In particular, Darwin wrote that ‘… the elevation of many hundred square miles of territory near Concepcion is part of the same phenomenon, with that splashing up, if I may so call it, of volcanic matter through the orifices in the Cordillera at the moment of the shock;…'. According to Darwin the crust is a system where fractured zones, and zones of seismic and volcanic activities interact. Darwin formulated the task of considering together the processes studied now as seismology and volcanology. However the difficulties are such that the study of interactions between earthquakes and volcanoes began only recently and his works on this had relatively little impact on the development of geosciences. In this report, we discuss how the latest data on seismic and volcanic events support the Darwin's observations and ideas about the 1835 Chilean earthquake. The material from researchspace. auckland. ac. nz/handle/2292/4474 is used. We show how modern mechanical tests from impact engineering and simple experiments with weakly-cohesive materials also support his observations and ideas. On the other hand, we developed the mathematical theory of the earthquake-induced catastrophic wave phenomena. This theory allow to explain the most important aspects the Darwin's earthquake reports. This is achieved through the simplification of fundamental governing equations of considering problems to strongly-nonlinear wave equations. Solutions of these equations are constructed with the help of analytic and numerical techniques. The solutions can model different strongly-nonlinear wave phenomena which generate in a variety of physical context. A comparison with relevant experimental observations is also presented.

  20. Predicted Attenuation Relation and Observed Ground Motion of Gorkha Nepal Earthquake of 25 April 2015

    NASA Astrophysics Data System (ADS)

    Singh, R. P.; Ahmad, R.

    2015-12-01

    A comparison of recent observed ground motion parameters of recent Gorkha Nepal earthquake of 25 April 2015 (Mw 7.8) with the predicted ground motion parameters using exitsing attenuation relation of the Himalayan region will be presented. The recent earthquake took about 8000 lives and destroyed thousands of poor quality of buildings and the earthquake was felt by millions of people living in Nepal, China, India, Bangladesh, and Bhutan. The knowledge of ground parameters are very important in developing seismic code of seismic prone regions like Himalaya for better design of buildings. The ground parameters recorded in recent earthquake event and aftershocks are compared with attenuation relations for the Himalayan region, the predicted ground motion parameters show good correlation with the observed ground parameters. The results will be of great use to Civil engineers in updating existing building codes in the Himlayan and surrounding regions and also for the evaluation of seismic hazards. The results clearly show that the attenuation relation developed for the Himalayan region should be only used, other attenuation relations based on other regions fail to provide good estimate of observed ground motion parameters.

  1. Assessment of precursory information in seismo-electromagnetic phenomena

    NASA Astrophysics Data System (ADS)

    Han, P.; Hattori, K.; Zhuang, J.

    2017-12-01

    Previous statistical studies showed that there were correlations between seismo-electromagnetic phenomena and sizeable earthquakes in Japan. In this study, utilizing Molchan's error diagram, we evaluate whether these phenomena contain precursory information and discuss how they can be used in short-term forecasting of large earthquake events. In practice, for given series of precursory signals and related earthquake events, each prediction strategy is characterized by the leading time of alarms, the length of alarm window, the alarm radius (area) and magnitude. The leading time is the time length between a detected anomaly and its following alarm, and the alarm window is the duration that an alarm lasts. The alarm radius and magnitude are maximum predictable distance and minimum predictable magnitude of earthquake events, respectively. We introduce the modified probability gain (PG') and the probability difference (D') to quantify the forecasting performance and to explore the optimal prediction parameters for a given electromagnetic observation. The above methodology is firstly applied to ULF magnetic data and GPS-TEC data. The results show that the earthquake predictions based on electromagnetic anomalies are significantly better than random guesses, indicating the data contain potential useful precursory information. Meanwhile, we reveal the optimal prediction parameters for both observations. The methodology proposed in this study could be also applied to other pre-earthquake phenomena to find out whether there is precursory information, and then on this base explore the optimal alarm parameters in practical short-term forecast.

  2. The 2008 earthquakes in the Bavarian Molasse Basin - possible relation to deep geothermics?

    NASA Astrophysics Data System (ADS)

    Kraft, T.; Wassermann, J.; Deichmann, N.; Stange, S.

    2009-04-01

    We discuss several microearthquakes of magnitude up to Ml=2.3 that occurred in the Bavarian Molasse Basin (ByM), south of Munich, Germany, in February and July 2008. The strongest event was felt by local residents. The Bavarian Earthquake catalog, which dates back to the year 1000, does list a small number of isolated earthquakes in the western part of the ByM as well as a cluster of mining induced earthquakes (Peißenberg 1962-1970, I0(MSK)=5.5). The eastern part of the ByM, including the wider surrounding of Munich, was so far considered aseismic. Due to the spatio-temporal clustering of the microearthquakes in February and July 2008 the University of Munich (LMU) and the Swiss Seismologcical Service installed a temporal network of seismological stations in the south of Munich to investigate the newly arising seismicity. First analysis of the recorded data indicate shallow source depths (~5km) for the July events. This result is supported by the fact that one of these very small earthquakes was felt by local residents. The earthquakes hypocenters are located closely to a number of deep geothermal wells of 3-4.5km depth being either in production or running productivity tests in late 2007 and early 2008. Therefore, the 2008 seimicity might represent a case of induced seimicity related to the injection or withdrawal of water from the hydrothermal aquifer. Due to the lack of high quality recordings of a denser seismic monitoring network in the source area it is not possible to resolve details of the processes behind the 2008 seismicity. Therefore, a definite answer to the question if the earthquakes are related the deep geothermal projects or not can not be given at present. However, a number of recent well-studied cases have proved that earthquakes can also happen in depths much shallower than 5km, and that small changes of the hydrological conditions at depth are sufficient to trigger seismicity. Therefore, a detailed understanding of the causative processes

  3. In search of earthquake-related hydrologic and chemical changes along Hayward Fault

    King, C.-Y.; Basler, D.; Presser, T.S.; Evans, William C.; White, L.D.; Minissale, A.

    1994-01-01

    Flow and chemical measurements have been made about once a month, and more frequently when required, since 1976 at two springs in Alum Rock Park in eastern San Jose, California, and since 1980 at two shallow wells in eastern Oakland in search of earthquake-related changes. All sites are on or near the Hayward Fault and are about 55 km apart. Temperature, electric conductivity, and water level or flow rate were measured in situ with portable instruments. Water samples were collected for later chemical and isotopic analyses in the laboratory. The measured flow rate at one of the springs showed a long-term decrease of about 40% since 1987, when a multi-year drought began in California. It also showed several increases that lasted a few days to a few months with amplitudes of 2.4 to 8.6 times the standard deviations above the background rate. Five of these increases were recorded shortly after nearby earthquakes of magnitude 5.0 or larger, and may have resulted from unclogging of the flow path and increase of permeability caused by strong seismic shaking. Two other flow increases were possibly induced by exceptionally heavy rainfalls. The water in both wells showed seasonal temperature and chemical variations, largely in response to rainfall. In 1980 the water also showed some clear chemical changes unrelated to rainfall that lasted a few months; these changes were followed by a magnitude 4 earthquake 37 km away. The chemical composition at one of the wells and at the springs also showed some longer-term variations that were not correlated with rainfall but possibly correlated with the five earthquakes mentioned above. These correlations suggest a common tectonic origin for the earthquakes and the anomalies. The last variation at the affected well occurred abruptly in 1989, shortly before a magnitude 5.0 earthquake 54 km away. ?? 1993.

  4. Characteristics of Gyeongju earthquake, moment magnitude 5.5 and relative relocations of aftershocks

    NASA Astrophysics Data System (ADS)

    Cho, ChangSoo; Son, Minkyung

    2017-04-01

    There is low seismicity in the korea peninsula. According historical record in the historic book, There were several strong earthquake in the korea peninsula. Especially in Gyeongju of capital city of the Silla dynasty, few strong earthquakes caused the fatalities of several hundreds people 1,300 years ago and damaged the houses and make the wall of castles collapsed. Moderate strong earthquake of moment magnitude 5.5 hit the city in September 12, 2016. Over 1000 aftershocks were detected. The numbers of occurrences of aftershock over time follows omori's law well. The distribution of relative locations of 561 events using clustering aftershocks by cross-correlation between P and S waveform of the events showed the strike NNE 25 30 o and dip 68 74o of fault plane to cause the earthquake matched with the fault plane solution of moment tensor inversion well. The depth of range of the events is from 11km to 16km. The width of distribution of event locations is about 5km length. The direction of maximum horizontal stress by inversion of stress for the moment solutions of main event and large aftershocks is similar to the known maximum horizontal stress direction of the korea peninsula. The relation curves between moment magnitude and local magnitude of aftershocks shows that the moment magnitude increases slightly more for events of size less than 2.0

  5. Dopants Diffusion in Silicon during Molecular Oxygen/nitrogen Trifluoride Oxidation and Related Phenomena

    NASA Astrophysics Data System (ADS)

    Kim, U. S.

    1990-01-01

    To date, chlorine has been used as useful additives in silicon oxidation. However, rapid scaling of device dimensions motivates the development of a new dielectric layer or modification of the silicon dioxide itself. More recently, chemically enhanced thermal oxidation by the use of fluorine containing species has been introduced to verify the potential of fluorine in the silicon oxidation process. In this study, gaseous nitrogen trifluoride (NF _3) was selected as the fluorine oxidizing source based on ease of use and was compared with the dichlorofluoroethane (C_2H _3Cl_2F) source. Two different kinds of boron marker samples were prepared and oxidized in O_2/NF_3 ambient for the comparison of surface vs bulk oxidation enhanced/retarded diffusion (OED/ORD). The phosphorus, arsenic and antimony diffusion in silicon during fluorine oxidation has been studied using the various covering layers such as SiO_2, Si_3 N_4, and SiO_2 + Si_3N_4 layers. The oxidation related phenomena, i.e. enhanced silicon and silicon nitride oxidation in fluorine ambient were studied and correlated with the point defect balance at the oxidizing interface. The results of this investigation were discussed with special emphasis on the effect of fluorine on enhanced oxidation and dopant diffusion.

  6. Biased resistor network model for electromigration failure and related phenomena in metallic lines

    NASA Astrophysics Data System (ADS)

    Pennetta, C.; Alfinito, E.; Reggiani, L.; Fantini, F.; Demunari, I.; Scorzoni, A.

    2004-11-01

    Electromigration phenomena in metallic lines are studied by using a biased resistor network model. The void formation induced by the electron wind is simulated by a stochastic process of resistor breaking, while the growth of mechanical stress inside the line is described by an antagonist process of recovery of the broken resistors. The model accounts for the existence of temperature gradients due to current crowding and Joule heating. Alloying effects are also accounted for. Monte Carlo simulations allow the study within a unified theoretical framework of a variety of relevant features related to the electromigration. The predictions of the model are in excellent agreement with the experiments and in particular with the degradation towards electrical breakdown of stressed Al-Cu thin metallic lines. Detailed investigations refer to the damage pattern, the distribution of the times to failure (TTFs), the generalized Black’s law, the time evolution of the resistance, including the early-stage change due to alloying effects and the electromigration saturation appearing at low current densities or for short line lengths. The dependence of the TTFs on the length and width of the metallic line is also well reproduced. Finally, the model successfully describes the resistance noise properties under steady state conditions.

  7. Mathematical, Constitutive and Numerical Modelling of Catastrophic Landslides and Related Phenomena

    NASA Astrophysics Data System (ADS)

    Pastor, M.; Fernández Merodo, J. A.; Herreros, M. I.; Mira, P.; González, E.; Haddad, B.; Quecedo, M.; Tonni, L.; Drempetic, V.

    2008-02-01

    Mathematical and numerical models are a fundamental tool for predicting the behaviour of geostructures and their interaction with the environment. The term “mathematical model” refers to a mathematical description of the more relevant physical phenomena which take place in the problem being analyzed. It is indeed a wide area including models ranging from the very simple ones for which analytical solutions can be obtained to those more complicated requiring the use of numerical approximations such as the finite element method. During the last decades, mathematical, constitutive and numerical models have been very much improved and today their use is widespread both in industry and in research. One special case is that of fast catastrophic landslides, for which simplified methods are not able to provide accurate solutions in many occasions. Moreover, many finite element codes cannot be applied for propagation of the mobilized mass. The purpose of this work is to present an overview of the different alternative mathematical and numerical models which can be applied to both the initiation and propagation mechanisms of fast catastrophic landslides and other related problems such as waves caused by landslides.

  8. Health behaviors of victims and related factors in Wenchuan earthquake resettlement sites.

    PubMed

    Liu, Qiaolan; Zhou, Hongyu; Zhou, Huan; Yang, Yang; Yang, Xiaoyan; Yu, Lingyun; Qiu, Peiyuan; Ma, Xiao

    2011-03-01

    The purpose of this study was to describe the health behaviors of earthquake victims related to gastrointestinal and respiratory infectious diseases in the centralized transitional earthquake resettlement sites in Wenchuan, China; and to identify key factors related to health behaviors that may inform local infectious diseases prevention and control strategies. Data were collected using a questionnaire that included questions about socio-demographic characteristics and health beliefs and behaviors. In total, 1411 participants were included through a two-stage random sampling strategy. A bivariate multilevel model was used to explore the related factors. Approximately 67% of the participants wash their hands after going to lavatories every time, and 87% felt uncomfortable spitting on the ground. The more the participants perceived their susceptibility to and the severity of infectious diseases, the better their health-related behaviors (P < 0.05). Both health-related behaviors were influenced by communication modes of health education (P = 0.01) and socio-demographic characteristics. There was heterogeneity of health-related behaviors among different resettlement sites (P < 0.01). Health education intervention, based on the Health Belief Model, is one of the main preventative strategies that should be implemented to inspire self-efficacy and to enhance better health-related behaviors among earthquake victims. Appropriate health education communication modes should be considered among different resettlement sites. Copyright © 2011 Elsevier Inc. All rights reserved.

  9. The Chiloé Mw 7.6 earthquake of 2016 December 25 in Southern Chile and its relation to the Mw 9.5 1960 Valdivia earthquake

    NASA Astrophysics Data System (ADS)

    Lange, Dietrich; Ruiz, Javier; Carrasco, Sebastián; Manríquez, Paula

    2018-04-01

    On 2016 December 25, an Mw 7.6 earthquake broke a portion of the Southern Chilean subduction zone south of Chiloé Island, located in the central part of the Mw 9.5 1960 Valdivia earthquake. This region is characterized by repeated earthquakes in 1960 and historical times with very sparse interseismic activity due to the subduction of a young (˜15 Ma), and therefore hot, oceanic plate. We estimate the coseismic slip distribution based on a kinematic finite-fault source model, and through joint inversion of teleseismic body waves and strong motion data. The coseismic slip model yields a total seismic moment of 3.94 × 1020 N.m that occurred over ˜30 s, with the rupture propagating mainly downdip, reaching a peak slip of ˜4.2 m. Regional moment tensor inversion of stronger aftershocks reveals thrust type faulting at depths of the plate interface. The fore- and aftershock seismicity is mostly related to the subduction interface with sparse seismicity in the overriding crust. The 2016 Chiloé event broke a region with increased locking and most likely broke an asperity of the 1960 earthquake. The updip limit of the main event, aftershocks, foreshocks and interseismic activity are spatially similar, located ˜15 km offshore and parallel to Chiloé Islands west coast. The coseismic slip model of the 2016 Chiloé earthquake suggests a peak slip of 4.2 m that locally exceeds the 3.38 m slip deficit that has accumulated since 1960. Therefore, the 2016 Chiloé earthquake possibly released strain that has built up prior to the 1960 Valdivia earthquake.

  10. The 2011 Tohoku-oki Earthquake related to a large velocity gradient within the Pacific plate

    NASA Astrophysics Data System (ADS)

    Matsubara, Makoto; Obara, Kazushige

    2015-04-01

    rays from the hypocenter around the coseismic region of the Tohoku-oki earthquake take off downward and pass through the Pacific plate. The landward low-V zone with a large anomaly corresponds to the western edge of the coseismic slip zone of the 2011 Tohoku-oki earthquake. The initial break point (hypocenter) is associated with the edge of a slightly low-V and low-Vp/Vs zone corresponding to the boundary of the low- and high-V zone. The trenchward low-V and low-Vp/Vs zone extending southwestward from the hypocenter may indicate the existence of a subducted seamount. The high-V zone and low-Vp/Vs zone might have accumulated the strain and resulted in the huge coseismic slip zone of the 2011 Tohoku earthquake. The low-V and low-Vp/Vs zone is a slight fluctuation within the high-V zone and might have acted as the initial break point of the 2011 Tohoku earthquake. Reference Matsubara, M. and K. Obara (2011) The 2011 Off the Pacific Coast of Tohoku earthquake related to a strong velocity gradient with the Pacific plate, Earth Planets Space, 63, 663-667. Okada, Y., K. Kasahara, S. Hori, K. Obara, S. Sekiguchi, H. Fujiwara, and A. Yamamoto (2004) Recent progress of seismic observation networks in Japan-Hi-net, F-net, K-NET and KiK-net, Research News Earth Planets Space, 56, xv-xxviii.

  11. In-situ investigation of relations between slow slip events, repeaters and earthquake nucleation

    NASA Astrophysics Data System (ADS)

    Marty, S. B.; Schubnel, A.; Gardonio, B.; Bhat, H. S.; Fukuyama, E.

    2017-12-01

    Recent observations have shown that, in subduction zones, imperceptible slip, known as "slow slip events", could trigger powerful earthquakes and could be link to the onset of swarms of repeaters. In the aim of investigating the relation between repeaters, slow slip events and earthquake nucleation, we have conducted stick-slip experiments on saw-cut Indian Gabbro under upper crustal stress conditions (up to 180 MPa confining pressure). During the past decades, the reproduction of micro-earthquakes in the laboratory enabled a better understanding and to better constrain physical parameters that are the origin of the seismic source. Using a new set of calibrated piezoelectric acoustic emission sensors and high frequency dynamic strain gages, we are now able to measure a large number of physical parameters during stick-slip motion, such as the rupture velocity, the slip velocity, the dynamic stress drop and the absolute magnitudes and sizes of foreshock acoustic emissions. Preliminary observations systemically show quasi-static slip accelerations, onset of repeaters as well as an increase in the acoustic emission rate before failure. In the next future, we will further investigate the links between slow slip events, repeaters, stress build-up and earthquakes, using our high-frequency acoustic and strain recordings and applying template matching analysis.

  12. Public Perception of Relative Risk: Earthquakes vs. Hurricanes in the San Diego Region

    NASA Astrophysics Data System (ADS)

    Means, J. D.

    2014-12-01

    Public perception of risk is key in pre-disaster preparation. Despite admonitions from emergency planners, people often fail to take reasonable precautions. But if emergency planners also fail to realize the possibility of a particular disaster scenario, there is very little chance that the public will plan for it. In Southern California there is a well-known risk associated with earthquakes, and it would be difficult to find anyone that didn't understand that the region was subject to risk from earthquakes. On the other hand, few, if any people consider the risk associated with tropical storms or hurricanes. This is reasonable considering people have always been told that the west coast of the United States is immune from hurricanes due to the cold water associated with the California Current, and the hazard of earthquakes is fairly obvious to anyone that has lived the for a while. Such an attitude is probably justifiable for most of Southern California, but it's unclear whether this is true for the San Diego region: destructive earthquakes are historically rare, and there is good evidence that the region was affected by a Category 1 hurricane in 1858. Indeed, during the last 70 years, more people have died from tropical cyclones in Calfornia's southernmost counties (San Diego and Imperial) than have died from earthquakes. In this paper we compare the relative risks from these two different types of disasters for the San Diego region, and attempt to answer why one type of hazard is emphasized in public planning and the other is neglected.

  13. Comparative Study of Earthquake Clustering in Relation to Hydraulic Activities at Geothermal Fields in California

    NASA Astrophysics Data System (ADS)

    Martínez-Garzón, P.; Zaliapin, I. V.; Ben-Zion, Y.; Kwiatek, G.; Bohnhoff, M.

    2017-12-01

    We investigate earthquake clustering properties from three geothermal reservoirs to clarify how earthquake patterns respond to hydraulic activities. We process ≈ 9 years from four datasets corresponding to the Geysers (both the entire field and a local subset), Coso and Salton Sea geothermal fields, California. For each, the completeness magnitude, b-value and fractal dimension are calculated and used to identify seismicity clusters using the nearest-neighbor approach of Zaliapin and Ben-Zion [2013a, 2013b]. Estimations of temporal evolution of different clustering properties in relation to hydraulic parameters point to different responses of earthquake dynamics to hydraulic operations in each case study. The clustering at the Geysers at local scale and Salton Sea are most and least affected by hydraulic activities, respectively. The response of the earthquake clustering from different datasets to the hydraulic activities may reflect the regional seismo-tectonic complexity as well as the dimension of the geothermal activities performed (e.g. number of active wells and superposition of injection + production activities).Two clustering properties significantly respond to hydraulic changes across all datasets: the background rates and the proportion of clusters consisting of a single event. Background rates are larger at the Geysers and Coso during high injection-production periods, while the opposite holds for the Salton Sea. This possibly reflects the different physical mechanisms controlling seismicity at each geothermal field. Additionally, a lower proportion of singles is found during time periods with higher injection-production rates. This may reflect decreasing effective stress in areas subjected to higher pore pressure and larger earthquake triggering by stress transfer.

  14. A Bayesian explanation of the "Uncanny Valley" effect and related psychological phenomena

    NASA Astrophysics Data System (ADS)

    Moore, Roger K.

    2012-11-01

    There are a number of psychological phenomena in which dramatic emotional responses are evoked by seemingly innocuous perceptual stimuli. A well known example is the `uncanny valley' effect whereby a near human-looking artifact can trigger feelings of eeriness and repulsion. Although such phenomena are reasonably well documented, there is no quantitative explanation for the findings and no mathematical model that is capable of predicting such behavior. Here I show (using a Bayesian model of categorical perception) that differential perceptual distortion arising from stimuli containing conflicting cues can give rise to a perceptual tension at category boundaries that could account for these phenomena. The model is not only the first quantitative explanation of the uncanny valley effect, but it may also provide a mathematical explanation for a range of social situations in which conflicting cues give rise to negative, fearful or even violent reactions.

  15. A Bayesian explanation of the ‘Uncanny Valley’ effect and related psychological phenomena

    PubMed Central

    Moore, Roger K.

    2012-01-01

    There are a number of psychological phenomena in which dramatic emotional responses are evoked by seemingly innocuous perceptual stimuli. A well known example is the ‘uncanny valley’ effect whereby a near human-looking artifact can trigger feelings of eeriness and repulsion. Although such phenomena are reasonably well documented, there is no quantitative explanation for the findings and no mathematical model that is capable of predicting such behavior. Here I show (using a Bayesian model of categorical perception) that differential perceptual distortion arising from stimuli containing conflicting cues can give rise to a perceptual tension at category boundaries that could account for these phenomena. The model is not only the first quantitative explanation of the uncanny valley effect, but it may also provide a mathematical explanation for a range of social situations in which conflicting cues give rise to negative, fearful or even violent reactions. PMID:23162690

  16. How personal earthquake experience impacts on the Stroop interference effect: an event-related potential study.

    PubMed

    Qiu, Jiang; Su, Yanhua; Li, Hong; Wei, Dongtao; Tu, Shen; Zhang, Qinglin

    2010-11-01

    Event-related brain potentials (ERPs) were measured when 24 Chinese subjects performed the classical Stroop task. All of subjects had experienced the great Sichuan earthquake (5/12), with 12 people in each of the Far (Chengdu city) and the Close (Deyang city) earthquake experience groups. The behavioral data showed that the Stroop task yielded a robust Stroop interference effect as indexed by longer RT for incongruent than congruent color words in both the Chengdu and Deyang groups. Scalp ERP data showed that incongruent stimuli elicited a more negative ERP deflection (N400-600; Stroop interference effect) than did congruent stimuli between 400-600 ms in the Chengdu group, while the Stroop interference ERP effect was not found in the Deyang group. Dipole source analysis localized the generator of the N400-600 in the right prefrontal cortex (PFC) and was possibly related to conflict monitoring and cognitive control. Copyright © 2010 Society for Psychophysiological Research.

  17. Earthquake-Related Orthopedic Injuries in Adult Population: A Systematic Review.

    PubMed

    Bortolin, Michelangelo; Morelli, Ilaria; Voskanyan, Amalia; Joyce, Nina R; Ciottone, Gregory R

    2017-04-01

    Introduction Earthquake-related trauma results in crush injuries and bony- and soft-tissue trauma. There are no systematic reviews analyzing the typical injury patterns and treatments in "Mega-Mass-Casualty" earthquakes. The characterization of an injury pattern specific to disaster type, be it natural or manmade, is imperative to build an effective disaster preparedness and response system. The systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A comprehensive search strategy was developed to identify all publications relating to earthquakes and the orthopedic treatment in adult patients. The following databases were searched: PubMed (Medline; US National Library of Medicine, National Institutes of Health; Bethesda, Maryland USA), Ovid (Ovid Technologies; New York, New York USA), Web of Science (Thomson Reuters; New York, New York USA), and The Cochrane Library (The Cochrane Collaboration; Oxford, United Kingdom). The searches identified 4,704 articles: 4,445 after duplicates were removed. The papers were screened for title and abstract and 65 out of those were selected for full-text analysis. The quality of data does not permit a standard-of-care (SOC) to be defined. Scarcity and poor quality of the data collected also may suggest a low level of accountability of the activity of the international hospital teams. Qualitatively, it is possible to define that there are more open fractures during daytime hours than at night. Excluding data about open and closed fractures, for all types of injuries, the results underline that the higher the impact of the earthquake, as measured by Richter Magnitude Scale (RMS), the higher is the number of injuries. Discussion Regarding orthopedic injuries during earthquakes, special attention must be paid to the management of the lower limbs most frequently injured. Spinal cord involvement following spine fractures is an important issue: this underlines how a

  18. Historical reconstruction of oil and gas spills during moderate and strong earthquakes and related geochemical surveys in Southern Apennines

    NASA Astrophysics Data System (ADS)

    Sciarra, Alessandra; Cantucci, Barbara; Ferrari, Graziano; Pizzino, Luca; Quattrocchi, Fedora

    2016-04-01

    The aim of this study is to contribute to the assessment of natural hazards in a seismically active area of southern Italy through the joint analysis of historical sources and fluid geochemistry. In particular, our studies have been focalized in the Val d'Agri basin, in the Apennines extensional belt, since it hosts the largest oilfield in onshore Europe and normal-fault systems with high seismogenic potential (up to M7). The work was organized into three main themes: 1) literature search aimed at identifying fluid emissions during previous moderate-strong earthquakes; 2) consultation of local and national archives to identify historic local place names correlated to natural fluids emissions; 3) geochemical sampling of groundwater and gas issuing at surface, identified on the basis of the bibliographic sources. A reasoned reading of written documents and available historical data was performed. Moreover, we reworked information reported in historical catalogues, referred to liquid and gas hydrocarbon leakages occurred during seismic events of the past (in a range of magnitude from 5 to 7) in the Southern Apennines (with a particular focus on the Val d'Agri). Special attention was given to the phenomena of geochemical emissions related to major historical earthquakes that took place in the area, most notably that of 16 December 1857 (M = 7). A careful analysis of the Robert Mallet's report, a complete work aimed at describing the social impact and the effects on the environment produced by this earthquake through illustrated maps and diagrams, included several hundred monoscopic and stereoscopic photographs, was done. From archival sources (at national and/or local administrations), "sensitive" sites to the onset of leakage of liquid and gaseous hydrocarbons in the past were identified. A soil-gas survey (22 gas concentrations and flux measurements) and 35 groundwater samplings were carried out in specific sites recognized through the above studies. From a

  19. Surface phenomena and the evolution of radiating fluid spheres in general relativity

    SciT

    Herrera, L.; Jimenez, J.; Esculpi, M.

    1989-10-01

    A method used to study the evolution of radiating spheres (Herrera, Jimenez, and Ruggeri) is extended to the case in which surface phenomena are taken into account. The equations have been integrated numerically for a model derived from the Schwarzschild interior solution, bringing out the effects of surface tension on the evolution of the spheres. 17 refs.

  20. Investigation of electrochemical phenomena related to corrosion in high temperature aqueous systems

    NASA Astrophysics Data System (ADS)

    Biswas, Ritwik

    1999-11-01

    Three separate phenomena, each related to the problem of corrosion of metals, in high temperature aqueous solutions, have been studied. These are: (1) Kinetics of the Hydrogen Oxidation Reaction (HOR), (2) Effect of solutions containing sulfur oxyanions on Stainless Steel 347 and Inconel 600, and (3) Characterization of electrochemical behavior of intermetallic compounds Ni3Nb and Ni3(TiAl). The anodic transfer coefficient and the Tafel constant, for the HOR, on platinized nickel, in 0.1 m NaOH solution, was experimentally measured over the temperature range of 25°C to 300°C. Potentiodynamic polarization experiments, under controlled hydrodynamic flow conditions, in a cell with annular flow geometry, were used for these measurements. The anodic transfer coefficient and the Tafel constant were found to increase with increase in solution temperature. At high anodic potentials (>1V vs. rest potential), passivation of the platinum electrode was observed. Electron tunneling theory was used to determine that this was the result of formation of platinum oxide (PtO) on the surface of the platinum electrode. The relative corrosion properties of Stainless Steel 347 and Inconel 600, exposed to an aqueous electrolyte containing sulfur oxyanions, at temperatures up to 285°C, was studied using electrochemical tests, mathematical modeling and surface analysis. The presence of sulfur oxyanions was found to cause the breakdown of the protective passive film on both the alloy surfaces, and increase their corrosion rates. As a result of exposure to the electrolyte, a porous layer of corrosion product was formed on both alloys. This porous layer was composed principally of Ni3S2 in the case of Inconel 600 and Fe3O4 in the case of Stainless Steel 347. The corrosive effect of sulfur oxyanions was found to be greater on Inconel 600 than Stainless Steel 347. Galvanic coupling experiments were conducted on the intermetallics Ni 3Nb and Ni3(TiAl) and a nickel rich alloy. It was

  1. Earthquake-Related Injuries in the Pediatric Population: A Systematic Review

    PubMed Central

    Jacquet, Gabrielle A.; Hansoti, Bhakti; Vu, Alexander; Bayram, Jamil D.

    2013-01-01

    Background: Children are a special population, particularly susceptible to injury. Registries for various injury types in the pediatric population are important, not only for epidemiological purposes but also for their implications on intervention programs. Although injury registries already exist, there is no uniform injury classification system for traumatic mass casualty events such as earthquakes. Objective: To systematically review peer-reviewed literature on the patterns of earthquake-related injuries in the pediatric population. Methods: On May 14, 2012, the authors performed a systematic review of literature from 1950 to 2012 indexed in Pubmed, EMBASE, Scopus, Web of Science, and Cochrane Library. Articles written in English, providing a quantitative description of pediatric injuries were included. Articles focusing on other types of disasters, geological, surgical, conceptual, psychological, indirect injuries, injury complications such as wound infections and acute kidney injury, case reports, reviews, and non-English articles were excluded. Results: A total of 2037 articles were retrieved, of which only 10 contained quantitative earthquake-related pediatric injury data. All studies were retrospective, had different age categorization, and reported injuries heterogeneously. Only 2 studies reported patterns of injury for all pediatric patients, including patients admitted and discharged. Seven articles described injuries by anatomic location, 5 articles described injuries by type, and 2 articles described injuries using both systems. Conclusions: Differences in age categorization of pediatric patients, and in the injury classification system make quantifying the burden of earthquake-related injuries in the pediatric population difficult. A uniform age categorization and injury classification system are paramount for drawing broader conclusions, enhancing disaster preparation for future disasters, and decreasing morbidity and mortality. PMID:24761308

  2. Salient Features of the 2015 Gorkha, Nepal Earthquake in Relation to Earthquake Cycle and Dynamic Rupture Models

    NASA Astrophysics Data System (ADS)

    Ampuero, J. P.; Meng, L.; Hough, S. E.; Martin, S. S.; Asimaki, D.

    2015-12-01

    Two salient features of the 2015 Gorkha, Nepal, earthquake provide new opportunities to evaluate models of earthquake cycle and dynamic rupture. The Gorkha earthquake broke only partially across the seismogenic depth of the Main Himalayan Thrust: its slip was confined in a narrow depth range near the bottom of the locked zone. As indicated by the belt of background seismicity and decades of geodetic monitoring, this is an area of stress concentration induced by deep fault creep. Previous conceptual models attribute such intermediate-size events to rheological segmentation along-dip, including a fault segment with intermediate rheology in between the stable and unstable slip segments. We will present results from earthquake cycle models that, in contrast, highlight the role of stress loading concentration, rather than frictional segmentation. These models produce "super-cycles" comprising recurrent characteristic events interspersed by deep, smaller non-characteristic events of overall increasing magnitude. Because the non-characteristic events are an intrinsic component of the earthquake super-cycle, the notion of Coulomb triggering or time-advance of the "big one" is ill-defined. The high-frequency (HF) ground motions produced in Kathmandu by the Gorkha earthquake were weaker than expected for such a magnitude and such close distance to the rupture, as attested by strong motion recordings and by macroseismic data. Static slip reached close to Kathmandu but had a long rise time, consistent with control by the along-dip extent of the rupture. Moreover, the HF (1 Hz) radiation sources, imaged by teleseismic back-projection of multiple dense arrays calibrated by aftershock data, was deep and far from Kathmandu. We argue that HF rupture imaging provided a better predictor of shaking intensity than finite source inversion. The deep location of HF radiation can be attributed to rupture over heterogeneous initial stresses left by the background seismic activity

  3. Switching Phenomena

    NASA Astrophysics Data System (ADS)

    Stanley, H. E.; Buldyrev, S. V.; Franzese, G.; Havlin, S.; Mallamace, F.; Mazza, M. G.; Kumar, P.; Plerou, V.; Preis, T.; Stokely, K.; Xu, L.

    One challenge of biology, medicine, and economics is that the systems treated by these serious scientific disciplines can suddenly "switch" from one behavior to another, even though they possess no perfect metronome in time. As if by magic, out of nothing but randomness one finds remarkably fine-tuned processes in time. The past century has, philosophically, been concerned with placing aside the human tendency to see the universe as a fine-tuned machine. Here we will address the challenge of uncovering how, through randomness (albeit, as we shall see, strongly correlated randomness), one can arrive at some of the many temporal patterns in physics, economics, and medicine and even begin to characterize the switching phenomena that enable a system to pass from one state to another. We discuss some applications of correlated randomness to understanding switching phenomena in various fields. Specifically, we present evidence from experiments and from computer simulations supporting the hypothesis that water's anomalies are related to a switching point (which is not unlike the "tipping point" immortalized by Malcolm Gladwell), and that the bubbles in economic phenomena that occur on all scales are not "outliers" (another Gladwell immortalization).

  4. Empirical relations to convert magnitudes of the earthquake catalogue for the north western of Algeria

    NASA Astrophysics Data System (ADS)

    Belayadi, Ilyes; Bezzeghoud, Mourad; Fontiela, João; Nadji, Amansour

    2017-04-01

    North Algeria is one of the most seismically active regions on the western Mediterranean basin and it is related with the boundaries of the Eurasian and Nubian plates. We compiled an earthquake catalogue for the north western of Algeria, within the area -2°W-1°E and 34°N-37°N for the time span 1790 - 2016. To compile the earthquake catalogue we merge all available catalogues either national and international. Then we remove all duplicates and fake earthquakes. The lower level of the catalogue entries is set at M = 2.5. Nevertheless, the magnitudes reported on the catalogue are ML, Ms, Mb, Mw and macroseismic intensity. Thus, we develop new empirical relations to calculate the Mw from the different magnitudes and intensity suitable to the seismic hazard and geodynamic context of North Algeria. Acknowledgements: Ilyes Belayadi is funded entirely by the University of Oran 2 Mohamed Ben Ahmed (Algeria). This work is co-financed by the European Union through the European Regional Development Fund under COMPETE 2020 (Operational Program for Competitiveness and Internationalization) through the ICT project (UID / GEO / 04683/2013) under the reference POCI-01-0145 -FEDER-007690.

  5. Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement

    Bonilla, Manuel G.; Mark, Robert K.; Lienkaemper, James J.

    1984-01-01

    In order to refine correlations of surface-wave magnitude, fault rupture length at the ground surface, and fault displacement at the surface by including the uncertainties in these variables, the existing data were critically reviewed and a new data base was compiled. Earthquake magnitudes were redetermined as necessary to make them as consistent as possible with the Gutenberg methods and results, which make up much of the data base. Measurement errors were estimated for the three variables for 58 moderate to large shallow-focus earthquakes. Regression analyses were then made utilizing the estimated measurement errors.The regression analysis demonstrates that the relations among the variables magnitude, length, and displacement are stochastic in nature. The stochastic variance, introduced in part by incomplete surface expression of seismogenic faulting, variation in shear modulus, and regional factors, dominates the estimated measurement errors. Thus, it is appropriate to use ordinary least squares for the regression models, rather than regression models based upon an underlying deterministic relation in which the variance results primarily from measurement errors.Significant differences exist in correlations of certain combinations of length, displacement, and magnitude when events are grouped by fault type or by region, including attenuation regions delineated by Evernden and others.Estimates of the magnitude and the standard deviation of the magnitude of a prehistoric or future earthquake associated with a fault can be made by correlating Ms with the logarithms of rupture length, fault displacement, or the product of length and displacement.Fault rupture area could be reliably estimated for about 20 of the events in the data set. Regression of Ms on rupture area did not result in a marked improvement over regressions that did not involve rupture area. Because no subduction-zone earthquakes are included in this study, the reported results do not apply to such

  6. Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement

    Bonilla, M.G.; Mark, R.K.; Lienkaemper, J.J.

    1984-01-01

    In order to refine correlations of surface-wave magnitude, fault rupture length at the ground surface, and fault displacement at the surface by including the uncertainties in these variables, the existing data were critically reviewed and a new data base was compiled. Earthquake magnitudes were redetermined as necessary to make them as consistent as possible with the Gutenberg methods and results, which necessarily make up much of the data base. Measurement errors were estimated for the three variables for 58 moderate to large shallow-focus earthquakes. Regression analyses were then made utilizing the estimated measurement errors. The regression analysis demonstrates that the relations among the variables magnitude, length, and displacement are stochastic in nature. The stochastic variance, introduced in part by incomplete surface expression of seismogenic faulting, variation in shear modulus, and regional factors, dominates the estimated measurement errors. Thus, it is appropriate to use ordinary least squares for the regression models, rather than regression models based upon an underlying deterministic relation with the variance resulting from measurement errors. Significant differences exist in correlations of certain combinations of length, displacement, and magnitude when events are qrouped by fault type or by region, including attenuation regions delineated by Evernden and others. Subdivision of the data results in too few data for some fault types and regions, and for these only regressions using all of the data as a group are reported. Estimates of the magnitude and the standard deviation of the magnitude of a prehistoric or future earthquake associated with a fault can be made by correlating M with the logarithms of rupture length, fault displacement, or the product of length and displacement. Fault rupture area could be reliably estimated for about 20 of the events in the data set. Regression of MS on rupture area did not result in a marked improvement

  7. Strong commitment to traditional Protestant religious beliefs is negatively related to beliefs in paranormal phenomena.

    PubMed

    Hillstrom, E L; Strachan, M

    2000-02-01

    Numerous studies have yielded small, negative correlations between measures of paranormal and "traditional religious beliefs". This may partly reflect opinions of Christians in the samples who take biblical sanctions against many "paranormal" activities seriously. To test this, 391 college students (270 women and 121 men) rated their beliefs in various paranormal phenomena and were classified as Believers, Nominal Believers, and Nonbelievers on the strength of their self-rated commitment to key biblical (particularly Protestant) doctrines. As predicted, Believers were significantly less likely than Nominal Believers or Nonbelievers to endorse reincarnation, contact with the dead, UFOs, telepathy, prophecy, psychokinesis, or healing, while the beliefs of Nominal Believers were similar to those of Nonbelievers. Substantial percentages of Nominal and Nonbelievers (30-50%) indicated at least moderate acceptance of the paranormal phenomena surveyed.

  8. Relative Contributions of Geothermal Pumping and Long-Term Earthquake Rate to Seismicity at California Geothermal Fields

    NASA Astrophysics Data System (ADS)

    Weiser, D. A.; Jackson, D. D.

    2015-12-01

    In a tectonically active area, a definitive discrimination between geothermally-induced and tectonic earthquakes is difficult to achieve. We focus our study on California's 11 major geothermal fields: Amedee, Brawley, Casa Diablo, Coso, East Mesa, The Geysers, Heber, Litchfield, Salton Sea, Susanville, and Wendel. The Geysers geothermal field is the world's largest geothermal energy producer. California's Department of Oil Gas and Geothermal Resources provides field-wide monthly injection and production volumes for each of these sites, which allows us to study the relationship between geothermal pumping activities and seismicity. Since many of the geothermal fields began injecting and producing before nearby seismic stations were installed, we use smoothed seismicity since 1932 from the ANSS catalog as a proxy for tectonic earthquake rate. We examine both geothermal pumping and long-term earthquake rate as factors that may control earthquake rate. Rather than focusing only on the largest earthquake, which is essentially a random occurrence in time, we examine how M≥4 earthquake rate density (probability per unit area, time, and magnitude) varies for each field. We estimate relative contributions to the observed earthquake rate of M≥4 from both a long-term earthquake rate (Kagan and Jackson, 2010) and pumping activity. For each geothermal field, respective earthquake catalogs (NCEDC and SCSN) are complete above at least M3 during the test period (which we tailor to each site). We test the hypothesis that the observed earthquake rate at a geothermal site during the test period is a linear combination of the long-term seismicity and pumping rates. We use a grid search to determine the confidence interval of the weighting parameters.

  9. Carbonate mounds from the Gulf of Cadiz in relation to methane seepage: unrelated phenomena or coupling?

    NASA Astrophysics Data System (ADS)

    Stadnitskaia, Alina; Baas, Marianne; de Haas, Henk; van Weering, Tjeerd C. E.; Kreulen, Rob R.; Sinninghe Damsté, Jaap S.

    2010-05-01

    For more than decade, the formation of carbonate mounds, related ecosystem development and organization/functioning of the entire mound habitats are subjects for a growing amount of studies and discussions. Carbonate mounds from the Gulf of Cadiz are of special interest due to their association with active mud volcanoes within the El Arraiche mud volcano field. Such co-occurrence of ecologically contrasting phenomena anticipates complex biogeochemical interactions between a carbonate mound interior and seeping through hydrocarbon-rich fluids. To get closer in understanding of how methane affects a carbonate mound development in the gulf, a combination of inorganic and organic geochemical techniques was applied to two sedimentary cores collected from summits of Alfa and Beta mounds. These mounds were found at the NW slope of the Gimini MV at the Pen Duick Mound Province. We analyzed vertical distribution profiles of sulfate, sulfide, chlorinity, DIC in combination with hydrocarbon gas measurements and lipid biomarker study. To have estimates of Sea Surface Temperature (SST) during the carbonate mound formation, we applied the TEX86 (TetraEther indeX of tetraethers with 86 carbon atoms; Schouten et al., 2002) and the alkenone-based UK37 index (Müller et al., 1998). The pore-water data revealed the presence of brine inflow, which is consistent with the data of Hensen et al., (2007). The behavior of sulfide distribution profiles and δ13C values from dissolved inorganic carbon (DIC) indicated that most of the sulfide and DIC are resulted from the microbial anaerobic oxidation of methane (AOM) processes. In contrast, the analysis of archaeal membrane lipids from distinct clades of AOM-mediating anaerobic methanotrophs showed exceedingly low concentrations of specific biomarkers, which is in contradiction with pore-water and gas chemistry data. Besides, AOM is the main cause for the increase of sedimentary alkalinity that leads to carbonate precipitation. Instead, some

  10. Studies related to the Charleston, South Carolina, earthquake of 1886; tectonics and seismicity

    Gottfried, David; Annell, C.S.; Byerly, G.R.; Lanphere, Marvin A.; Phillips, Jeffrey D.; Gohn, Gregory S.; Houser, Brenda B.; Schneider, Ray R.; Ackermann, Hans D.; Yantis, B.R.; Costain, John K.; Schilt, F. Steve; Brown, Larry; Oliver, Jack E.; Kaufman, Sidney; Hamilton, Robert Morrison; Behrendt, John C.; Henry, V. James; Bayer, Kenneth C.; Daniels, David L.; Zietz, Isidore; Popenoe, Peter; Chowns, T.M.; Williams, C.T.; Dooley, Robert E.; Wampler, J.; Dillon, William P.; Klitgord, Kim D.; Paull, Charles K.; McGinnis, Lyle D.; Dewey, James W.; Tarr, Arthur C.; Rhea, Susan; Wentworth, Carl M.; Mergner-Keefer, Marcia; Bollinger, G.A.; Gohn, Gregory S.

    1983-01-01

    Since 1973, the U.S. Geological Survey (USGS), with support from the Nuclear Regulatory Commission, has conducted extensive investigations of the tectonic and seismic history of the Charleston, S.C., earthquake zone and surrounding areas. The goal of these investigations has been to discover the cause of the large intraplate Charleston earthquake of 1886, which dominates the record of seismicity in the Southeastern United States, through an understanding of the historic and modern seismicity at Charleston and of the tectonic setting of the seismicity. This goal is being pursued to evaluate the potential for additional large earthquakes in the Charleston area and surrounding regions and to determine whether the Charleston area differs tectonically in any significant fashion from other parts of the Southeastern United States. An understanding of the specific cause for the 1886 event and of the regional distribution of any structures that are generically related to or geometrically and mechanically similar to the source structure is essential for evaluation of seismic hazards throughout the Southeast.The results given herein represent significant progress toward understanding the tectonic setting of the Charleston-area seismicity. Several chapters in the volume address the distribution and origin of pre-Cretaceous rocks and structures beneath Coastal Plain sediments in the Charleston area and regionally beneath the southern Atlantic Coastal Plain and adjacent Continental Shelf. The modern seismicity at Charleston is occurring at depths equal to or greater than the known extent of these older structures, and rejuvenation of an older fault in the modern stress field is a possible cause of the seismicity. Accordingly, several chapters discuss the possible relationships of the various pre-Cretaceous structures to faults identified near Charleston that have a known Cretaceous and Cenozoic movement history and to the historic and instrumentally recorded seismicity. However

  11. The Cascadia Subduction Zone and related subduction systems: seismic structure, intraslab earthquakes and processes, and earthquake hazards

    Kirby, Stephen H.; Wang, Kelin; Dunlop, Susan

    2002-01-01

    The following report is the principal product of an international workshop titled “Intraslab Earthquakes in the Cascadia Subduction System: Science and Hazards” and was sponsored by the U.S. Geological Survey, the Geological Survey of Canada and the University of Victoria. This meeting was held at the University of Victoria’s Dunsmuir Lodge, Vancouver Island, British Columbia, Canada on September 18–21, 2000 and brought 46 participants from the U.S., Canada, Latin America and Japan. This gathering was organized to bring together active research investigators in the science of subduction and intraslab earthquake hazards. Special emphasis was given to “warm-slab” subduction systems, i.e., those systems involving young oceanic lithosphere subducting at moderate to slow rates, such as the Cascadia system in the U.S. and Canada, and the Nankai system in Japan. All the speakers and poster presenters provided abstracts of their presentations that were a made available in an abstract volume at the workshop. Most of the authors subsequently provided full articles or extended abstracts for this volume on the topics that they discussed at the workshop. Where updated versions were not provided, the original workshop abstracts have been included. By organizing this workshop and assembling this volume, our aim is to provide a global perspective on the science of warm-slab subduction, to thereby advance our understanding of internal slab processes and to use this understanding to improve appraisals of the hazards associated with large intraslab earthquakes in the Cascadia system. These events have been the most frequent and damaging earthquakes in western Washington State over the last century. As if to underscore this fact, just six months after this workshop was held, the magnitude 6.8 Nisqually earthquake occurred on February 28th, 2001 at a depth of about 55 km in the Juan de Fuca slab beneath the southern Puget Sound region of western Washington. The Governor

  12. Near field earthquake sources scenarios and related tsunamis on the French-Italian Riviera (Western Mediterranean

    NASA Astrophysics Data System (ADS)

    Larroque, Christophe; Ioualalen, Mansour; Scotti, Oona

    2014-05-01

    The large system of thrust faults recently evidenced at the foot of the northern Ligurian margin accommodates the inversion of this ancient passive margin since at least 5 Ma (Messinian times). At depth, these faults are certainly connected to a major northward dipping thrust that accounts for the major part of the seismicity in the northern Ligurian Sea. The deformations of the Quaternary sediments along the faults attest to a compressive tectonic regime consistent with the focal mechanisms of earthquakes. The major event in the area (the Ligurian earthquake, 1887/02/23, Mw 6.7-6.9 and the related tsunami) could result from the activation of part of the Ligurian thrust. Starting from the Ligurian earthquake source characteristics (strike: N55°E, dip: 16°N, length: 35 km, width: 17 km, co-seismic slip: 1.5 m, focal depth: 15 km, Mw 6.9), we have built an exhaustive set of earthquake scenarios involving the 80 km long Ligurian thrust. (1) Two of these earthquake scenarios ruptured respectively the eastern (offshore Imperia) and western (offshore Nice) part of the Ligurian thrust. (2) As these scenarios must scan the range of potential events in accordance with the geology, a second group of scenarios tests an 80 km long rupture of the entire Ligurian thrust with different strikes (N55°E and N70°E) and different widths of the faulting surface (17 km and 27 km) and then co-seismic slips of 2 m and 3.3 m, respectively. As the Ligurian coast is a densely populated and industrial area, the vulnerability is high. We want to stress here that we are more concerned with tsunamis triggered by local earthquakes. This is because, considering their arrival times (a few minutes), the risk prevention cannot be handled by existing tsunami warning system. For all scenarios we evaluate the tsunami coastal impact. The spatial distribution of the maximum wave height (MWH) is provided with a tentative identification of the processes that are responsible for it. The predictions

  13. A study on flash sintering and related phenomena in titania and its composite with alumina

    NASA Astrophysics Data System (ADS)

    Shikhar

    In 2010, Cologna et. al. [1] reported that with a help of small electric field 120 Vcm-1, the sintering temperature of 3 mol % yittria stabilized zirconia could be brought down to 850°C from 1450°C. On top of reducing the temperature requirements, the green sample could be sintered from starting density of 50% to near full density in mere 5 seconds, a sintering rate three orders of magnitude higher than conventional methods. This discovery led to the emergence of a new field of enhanced sintering with electric field, named "Flash Sintering". The objective of this thesis is to understand the phenomenological behavior of flash-sintering and related phenomena on titania and its composites with alumina at elevated temperature. The possible mechanisms to explain flash sintering are discussed: Joule heating and the avalanche of defect generation [2], both induced by the rapid rise in conductivity just before the onset of the flash. Apparently, both mechanisms play a role. The thesis covers the response of pure titania and composites of titania-alumina under flash and compared with conventional sintering. We start with the sintering behavior of pure titania and observe lowering of sintering temperature requirements with higher applied electric field. The conductivity of titania during flash is also measured, and compared with the nominal conductivity of titania at equivalent temperatures. The conductivity during flash is determined to be have a different activation energy. For the composites of titania-alumina, effect of flash on the constrained sintering was studied. It is a known fact that sintering of one component of composite slows down when the other component of a different densification rate is added to it, called constrained sintering. In our case, large inclusions of alumina particles were added to nano-grained titania green compact that hindered its densification. Flash sintering was found to be overcoming this problem and near full densification was achieved

  14. Paranormal phenomena

    NASA Astrophysics Data System (ADS)

    Gaina, Alex

    1996-08-01

    Critical analysis is given of some paranormal phenomena events (UFO, healers, psychokinesis (telekinesis))reported in Moldova. It is argued that correct analysis of paranormal phenomena should be made in the framework of electromagnetism.

  15. Transient AC voltage related phenomena for HVDC schemes connected to weak AC systems

    SciT

    Pilotto, L.A.S.; Szechtman, M.; Hammad, A.E.

    1992-07-01

    In this paper a didactic explanation of voltage stability associated phenomena at HVDC terminals is presented. Conditions leading to ac voltage collapse problems are identified. A mechanism that excites control-induced voltage oscillations is shown. The voltage stability factor is used for obtaining the maximum power limits of ac/dc systems operating with different control strategies. Correlation to Pd {times} Id curves is given. Solutions for eliminating the risks of voltage collapse and for avoiding control-induced oscillations are discussed. The results are supported by detailed digital simulations of a weak ac/dc system using EMTP.

  16. A new strategy for earthquake focal mechanisms using waveform-correlation-derived relative polarities and cluster analysis: Application to the 2014 Long Valley Caldera earthquake swarm

    Shelly, David R.; Hardebeck, Jeanne L.; Ellsworth, William L.; Hill, David P.

    2016-01-01

    In microseismicity analyses, reliable focal mechanisms can typically be obtained for only a small subset of located events. We address this limitation here, presenting a framework for determining robust focal mechanisms for entire populations of very small events. To achieve this, we resolve relative P and S wave polarities between pairs of waveforms by using their signed correlation coefficients—a by-product of previously performed precise earthquake relocation. We then use cluster analysis to group events with similar patterns of polarities across the network. Finally, we apply a standard mechanism inversion to the grouped data, using either catalog or correlation-derived P wave polarity data sets. This approach has great potential for enhancing analyses of spatially concentrated microseismicity such as earthquake swarms, mainshock-aftershock sequences, and industrial reservoir stimulation or injection-induced seismic sequences. To demonstrate its utility, we apply this technique to the 2014 Long Valley Caldera earthquake swarm. In our analysis, 85% of the events (7212 out of 8494 located by Shelly et al. [2016]) fall within five well-constrained mechanism clusters, more than 12 times the number with network-determined mechanisms. Of the earthquakes we characterize, 3023 (42%) have magnitudes smaller than 0.0. We find that mechanism variations are strongly associated with corresponding hypocentral structure, yet mechanism heterogeneity also occurs where it cannot be resolved by hypocentral patterns, often confined to small-magnitude events. Small (5–20°) rotations between mechanism orientations and earthquake location trends persist when we apply 3-D velocity models and might reflect a geometry of en echelon, interlinked shear, and dilational faulting.

  17. Improvement of Earthquake Epicentral Locations Using T-Phases: Testing by Comparison With Surface Wave Relative Event Locations

    DTIC Science & Technology

    2001-10-01

    deployment of 51 ocean -bottom seismometers (OBS) on the seafloor spanning 800 km across the East Pacific Rise provides a unique opportunity to test the...aftershock sequence of earthquakes at the northern end of the Easter microplate . In addition, for the larger earthquakes, we can compare relative... ocean -bottom seismometers OBJECTIVES The objectives of this research are To explore the synergy between hydroacoustic and seismic techniques

  18. Accelerated Seismic Release and Related Aspects of Seismicity Patterns on Earthquake Faults

    NASA Astrophysics Data System (ADS)

    Ben-Zion, Y.; Lyakhovsky, V.

    2001-05-01

    Observational studies indicate that large earthquakes are sometimes preceded by phases of accelerated seismic release (ASR) characterized by cumulative Benioff strain following a power law time-to-failure relation with a term (tf - t)m, where tf is the failure time of the large event and observed values of m are close to 0.3. We discuss properties of ASR and related aspects of seismicity patterns associated with several theoretical frameworks, with a focus on models of heterogeneous faults in continuum solids. Using stress and earthquake histories simulated by the model of Ben-Zion (1996) for a discrete fault with quenched heterogeneities in a 3D elastic half space, we show that large model earthquakes are associated with non-repeating cyclical establishment and destruction of long-range stress correlations, accompanied by non-stationary cumulative Benioff strain release. We then analyze results associated with a regional lithospheric model consisting of a seismogenic upper crust governed by the damage rheology of Lyakhovsky et al. (1997) over a viscoelastic substrate. We demonstrate analytically for a simplified 1D case that the employed damage rheology leads to a singular power law equation for strain proportional to (tf - t)-1/3, and a non-singular power law relation for cumulative Benioff strain proportional to (tf - t)1/3. A simple approximate generalization of the latter for regional cumulative Benioff strain is obtained by adding to the result a linear function of time representing a stationary background release. To go beyond the analytical expectations, we examine results generated by various realizations of the regional lithospheric model producing seismicity following the characteristic frequency-size statistics, Gutenberg-Richter power law distribution, and mode switching activity. We find that phases of ASR exist only when the seismicity preceding a given large event has broad frequency-size statistics. In such cases the simulated ASR phases can be

  19. Earthquakes and aseismic creep associated with growing fault-related folds

    NASA Astrophysics Data System (ADS)

    Burke, C. C.; Johnson, K. M.

    2017-12-01

    Blind thrust faults overlain by growing anticlinal folds pose a seismic risk to many urban centers in the world. A large body of research has focused on using fold and growth strata geometry to infer the rate of slip on the causative fault and the distribution of off-fault deformation. However, because we have had few recorded large earthquakes on blind faults underlying folds, it remains unclear how much of the folding occurs during large earthquakes or during the interseismic period accommodated by aseismic creep. Numerous kinematic and mechanical models as well as field observations demonstrate that flexural slip between sedimentary layering is an important mechanism of fault-related folding. In this study, we run boundary element models of flexural-slip fault-related folding to examine the extent to which energy is released seismically or aseismically throughout the evolution of the fold and fault. We assume a fault imbedded in viscoelastic mechanical layering under frictional contact. We assign depth-dependent frictional properties and adopt a rate-state friction formulation to simulate slip over time. We find that in many cases, a large percentage (greater than 50%) of fold growth is accomplished by aseismic creep at bedding and fault contacts. The largest earthquakes tend to occur on the fault, but a significant portion of the seismicity is distributed across bedding contacts through the fold. We are currently working to quantify these results using a large number of simulations with various fold and fault geometries. Result outputs include location, duration, and magnitude of events. As more simulations are completed, these results from different fold and fault geometries will provide insight into how much folding occurs from these slip events. Generalizations from these simulations can be compared with observations of active fault-related folds and used in the future to inform seismic hazard studies.

  20. Accelerated Seismic Release and Related Aspects of Seismicity Patterns on Earthquake Faults

    NASA Astrophysics Data System (ADS)

    Ben-Zion, Y.; Lyakhovsky, V.

    Observational studies indicate that large earthquakes are sometimes preceded by phases of accelerated seismic release (ASR) characterized by cumulative Benioff strain following a power law time-to-failure relation with a term (tf-t)m, where tf is the failure time of the large event and observed values of m are close to 0.3. We discuss properties of ASR and related aspects of seismicity patterns associated with several theoretical frameworks. The subcritical crack growth approach developed to describe deformation on a crack prior to the occurrence of dynamic rupture predicts great variability and low asymptotic values of the exponent m that are not compatible with observed ASR phases. Statistical physics studies assuming that system-size failures in a deforming region correspond to critical phase transitions predict establishment of long-range correlations of dynamic variables and power-law statistics before large events. Using stress and earthquake histories simulated by the model of Ben-Zion (1996) for a discrete fault with quenched heterogeneities in a 3-D elastic half space, we show that large model earthquakes are associated with nonrepeating cyclical establishment and destruction of long-range stress correlations, accompanied by nonstationary cumulative Benioff strain release. We then analyze results associated with a regional lithospheric model consisting of a seismogenic upper crust governed by the damage rheology of Lyakhovskyet al. (1997) over a viscoelastic substrate. We demonstrate analytically for a simplified 1-D case that the employed damage rheology leads to a singular power-law equation for strain proportional to (tf-t)-1/3, and a nonsingular power-law relation for cumulative Benioff strain proportional to (tf-t)1/3. A simple approximate generalization of the latter for regional cumulative Benioff strain is obtained by adding to the result a linear function of time representing a stationary background release. To go beyond the analytical

  1. Registration in a radon system of signals related to the Tohoku Earthquake

    NASA Astrophysics Data System (ADS)

    Steinitz, Gideon; Piatibratova, Oksana; Kotlarsky, Peter

    2013-04-01

    The behavior of radon (Rn-222) within confined volumes of air is examined experimentally at the GSI (Jerusalem) since several years. In these experiments a relatively high level of radon is maintained by diffusion from a source via a tube and radiation from it is measured using nuclear detectors. In difference with the expected, nuclear radiation from the radon (progeny) shows: a) temporal variations (signals) spanning annual to daily scale; b) directionality of the nuclear radiation reflected as inverse signal patterns in the east-west versus north-south directions. The experimental setup at the GSI lab consists of a leak tight stainless steel (SS) canister (3.53 l) fed with radon by diffusing via SS tube (0.8 m) from a commercial source (RaCl2; 103 kBq). Four identical gamma detectors (2×2") were placed around its central horizontal plane of the canister, at the primary geographic directions, and a further detector (36×76 mm) was placed along the vertical axis of the canister. Count rates (1-minute intervals) were acquired by a datalogger. The system was used in this configuration in a series of experiments conducted from May 2009 to June 2012. An experiment was operating from 30.1.2011 to 22.3.11. The host gas in this experiment was argon at a pressure of ~1 atmosphere. Distinctive short term periodic (STP) signals with periods of 2-3 hours (frequencies in the range of 9-12 CPD) occur in a time interval of three days in association with the Tohoku earthquake (TE; 11.3.2011) and possibly also with its pre-shock. The STP signals occur from around 6 hours prior to the TE and are maintained to around 48 hours after the TE. These signals are observed at all five sensors and are superimposed on the DR signals with relative amplitudes of around 20%. They exhibit differing forms and phase at the different sensors, located at different directions around the canister. The pattern is similar but not identical to the spatial manifestation of form and phase of the DR

  2. Localization and Related Phenomena in Multiply Connected Nanostructured Inverse Opal Bismuth

    NASA Astrophysics Data System (ADS)

    Bleiweiss, Michael; Saygi, Salih; Amirzadeh, Jafar; Datta, Timir; Lungu, Anca; Yin, Ming; Palm, Eric; Brandt, Bruce; Iqbal, Zafar

    2001-03-01

    The nanostructures were fabricated by pressure infiltration of bismuth into porous artificial opal and were characterized using SEM, EDX and XRD. These structures form a regular three-dimensional network in which the bismuth regions percolate in all directions between the close packed spheres of SiO_2. The sizes of the conducting regions are of the order of tens of nanometers. The static magnetic properties of both bismuth inverse opal and bulk bismuth were studied using a SQUID magnetometer. Transport measurements, including Hall, were done using standard ac four and six probe techniques in fields up to 17 T* and temperatures between 4.2 and 150 K. The results of these measurements, including the observation of localization phenomena, will be discussed. Comparisons will be made with published results on bismuth nanowires. *Performed at the National High Magnetic Field Lab (NHMFL) FSU, Tallahassee, FL. Partially supported by a grant from NASA.

  3. A Study of Aircraft Fire Hazards Related to Natural Electrical Phenomena

    NASA Technical Reports Server (NTRS)

    Kester, Frank L.; Gerstein, Melvin; Plumer, J. A.

    1960-01-01

    The problems of natural electrical phenomena as a fire hazard to aircraft are evaluated. Assessment of the hazard is made over the range of low level electrical discharges, such as static sparks, to high level discharges, such as lightning strikes to aircraft. In addition, some fundamental work is presented on the problem of flame propagation in aircraft fuel vent systems. This study consists of a laboratory investigation in five parts: (1) a study of the ignition energies and flame propagation rates of kerosene-air and JP-6-air foams, (2) a study of the rate of flame propagation of n-heptane, n-octane, n-nonane, and n-decane in aircraft vent ducts, (3) a study of the damage to aluminum, titanium, and stainless steel aircraft skin materials by lightning strikes, (4) a study of fuel ignition by lightning strikes to aircraft skins, and (5) a study of lightning induced flame propagation in an aircraft vent system.

  4. The 1906 earthquake and a century of progress in understanding earthquakes and their hazards

    Zoback, M.L.

    2006-01-01

    The 18 April 1906 San Francisco earthquake killed nearly 3000 people and left 225,000 residents homeless. Three days after the earthquake, an eight-person Earthquake Investigation Commission composed of 25 geologists, seismologists, geodesists, biologists and engineers, as well as some 300 others started work under the supervision of Andrew Lawson to collect and document physical phenomena related to the quake . On 31 May 1906, the commission published a preliminary 17-page report titled "The Report of the State Earthquake Investigation Commission". The report included the bulk of the geological and morphological descriptions of the faulting, detailed reports on shaking intensity, as well as an impressive atlas of 40 oversized maps and folios. Nearly 100 years after its publication, the Commission Report remains a model for post-earthquake investigations. Because the diverse data sets were so complete and carefully documented, researchers continue to apply modern analysis techniques to learn from the 1906 earthquake. While the earthquake marked a seminal event in the history of California, it served as impetus for the birth of modern earthquake science in the United States.

  5. Swellable clay minerals in weathering products of volcanic sediments related to landslides by 2016 Kumamoto Earthquake

    NASA Astrophysics Data System (ADS)

    Isobe, H.; Torii, M.

    2016-12-01

    2016 Kumamoto Earthquake triggered numerous landslides in Aso caldera area, Japan and incurred heavy casualties. Landslides occurred not only on steep slopes at the caldera cliffs or the barranco but also on relatively gradual slopes at the side of the central cones in the Aso caldera. The Aso volcano is a volcanic complex with huge caldera formed by catastrophic eruption at approximately 90ka and central cones formed by subsequent activities to recent years. The central cones are volcanic peaks contain various rocks including basaltic, andesitic and rhoyolitic lavas and pyroclastic materials. In this study, we analyzed the samples collected from the bottom surface of landslides occurred at the gradual hillside on the western flank of the Aso central cones. The subsurface geology of the site is Takanoobane rhyolite lava, 51ka, covered by dark silty or pelitic tuffs and black soil strata including Kusasenri pumice layer, 31ka. The bottom plane of the landslides can be seen as flat surfaces at boundaries between units in the Kusasenri pumice or bottom of the Kusasenri pumice on the pelitic tuff with charcoaled plants. The Kusasenri pumice layer is a coarse grained and highly permeable but poorly continuous. X-ray diffraction analysis revealed that the main component of the samples is halloysite (10Å). Halloysite (10Å) is alteration product of fine grained volcanic ash, and swellable clay with interlayer water molecules which bring sticky and deformable characteristics. The landslides caused by 2016 Kumamoto Earthquake occurred without precipitation within a week. Strong earthquake may fluidize swellable clay layers in gradual slopes and triggered heavy landslides.

  6. A public health issue related to collateral seismic hazards: The valley fever outbreak triggered by the 1994 Northridge, California earthquake

    Jibson, R.W.

    2002-01-01

    Following the 17 January 1994 Northridge. California earthquake (M = 6.7), Ventura County, California, experienced a major outbreak of coccidioidomycosis (CM), commonly known as valley fever, a respiratory disease contracted by inhaling airborne fungal spores. In the 8 weeks following the earthquake (24 January through 15 March), 203 outbreak-associated cases were reported, which is about an order of magnitude more than the expected number of cases, and three of these cases were fatal. Simi Valley, in easternmost Ventura County, had the highest attack rate in the county, and the attack rate decreased westward across the county. The temporal and spatial distribution of CM cases indicates that the outbreak resulted from inhalation of spore-contaminated dust generated by earthquake-triggered landslides. Canyons North East of Simi Valley produced many highly disrupted, dust-generating landslides during the earthquake and its aftershocks. Winds after the earthquake were from the North East, which transported dust into Simi Valley and beyond to communities to the West. The three fatalities from the CM epidemic accounted for 4 percent of the total earthquake-related fatalities.

  7. Archaeoseismology in Algeria: observed damages related to probable past earthquakes on archaeological remains on Roman sites (Tel Atlas of Algeria)

    NASA Astrophysics Data System (ADS)

    Roumane, Kahina; Ayadi, Abdelhakim

    2017-04-01

    The seismological catalogue for Algeria exhibits significant lack for the period before 1365. Some attempts led to retrieve ancient earthquakes evidenced by historical documents and achieves. Archaeoseismology allows a study of earthquakes that have affected archaeological sites, based on the analysis of damage observed on remains. We have focused on the Antiquity period that include Roman, Vandal and Byzantine period from B.C 146 to A.D. 533. This will contribute significantly to the understanding of seismic hazard of the Tell Atlas region known as an earthquake prone area. The Tell Atlas (Algeria) experienced during its history many disastrous earthquakes their impacts are graved on landscape and archaeological monuments. On Roman sites such, Lambaesis (Lambèse), Thamugadi (Timgad) Thibilis (Salaoua Announa) or Thevest (Tebessa), damage were observed on monuments and remains related to seismic events following strong shacking or other ground deformation (subsidence, landslide). Examples of observed damage and disorders on several Roman sites are presented as a contribution to Archaeoseismology in Algeria based on effects of earthquakes on ancient structures and monuments. Keywords : Archaeoseismology. Lambaesis. Drop columns. Aspecelium. Ancient earthquakes

  8. A Public Health Issue Related To Collateral Seismic Hazards: The Valley Fever Outbreak Triggered By The 1994 Northridge, California Earthquake

    NASA Astrophysics Data System (ADS)

    Jibson, Randall W.

    Following the 17 January 1994 Northridge, California earthquake (M = 6.7), Ventura County, California, experienced a major outbreak ofcoccidioidomycosis (CM), commonly known as valley fever, a respiratory disease contracted byinhaling airborne fungal spores. In the 8 weeks following the earthquake (24 Januarythrough 15 March), 203 outbreak-associated cases were reported, which is about an order of magnitude more than the expected number of cases, and three of these cases were fatal.Simi Valley, in easternmost Ventura County, had the highest attack rate in the county,and the attack rate decreased westward across the county. The temporal and spatial distribution of CM cases indicates that the outbreak resulted from inhalation of spore-contaminated dust generated by earthquake-triggered landslides. Canyons North East of Simi Valleyproduced many highly disrupted, dust-generating landslides during the earthquake andits aftershocks. Winds after the earthquake were from the North East, which transporteddust into Simi Valley and beyond to communities to the West. The three fatalities from the CM epidemic accounted for 4 percent of the total earthquake-related fatalities.

  9. Tsunami Mapping Related to Local Earthquakes on the French-Italian Riviera (Western Mediterranean)

    NASA Astrophysics Data System (ADS)

    Ioualalen, Mansour; Larroque, Christophe; Scotti, Oona; Daubord, Camille

    2014-07-01

    The Ligurian coast, located at the French-Italian border, is densely populated as well as a touristic area. It is also a location where earthquakes and underwater landslides are recurrent. The nature of the local tsunamigenesis is therefore a legitimate question, because no tsunami warning system can resolve tsunami arrival times of a few minutes, which is the case for the area. As far as the seismicity of the area is concerned, the frequent recurrent earthquakes are generally of moderate magnitude: most of them are lower than M w 5. However, the relatively large M w 6.9 earthquake (Larroque et al., in Geophys J Int, 2012. doi: 10.1111/j.1365-246X.2012.05498.x) that occurred on the February 23, 1887, offshore of Imperia (Italian Riviera) is quite emblematic. This unusual event for the region merits a complete study: the quantification of its rupture mechanism is essential (1) to understand the regional active deformation, but also (2) to evaluate its tsunamigenesis potential by deriving relevant rupture scenarios obtained from our knowledge of the event; for that purpose the event is extensively described here. The first point has been the subject of quite a few studies based on the seismotectonics of the area. The last documented approach has been completed by Larroque et al. (Geophys J Int, 2012. doi: 10.1111/j.1365-246X.2012.05498.x) who proposed a rupture scenario involving a reverse faulting along a north dipping fault and favoring a M w 6.9 magnitude. In the present paper (1) we study the accuracy of their solutions in relation to the computational grid spacing and the dispersive/nondispersive parameterization, (2) based on an uncertainty on the recorded wave amplitude of the Genoa tide gauge they used, we propose a M w 6.7 earthquake magnitude solution for the event (the kinematics is unchanged), co-existing with the M w 6.9, (3) we evaluate the tsunami coastal impact of the 1887 event, and (4) we test a range of possible ruptures that local faults may

  10. Slip in Great Megathrust Earthquakes and its Relation to Crustal Structure as Revealed by Satellite Free-air Gravity

    NASA Astrophysics Data System (ADS)

    Wells, R. E.; Blakely, R. J.; Scholl, D.

    2007-12-01

    In 2003, Song and Simons and Wells et al. showed that approximately 70% of the moment released during past large, shallow subduction zone thrust earthquakes occurred beneath trench-parallel, free-air gravity lows outlining the deep-sea slope terrace and its basins. The authors suggested that the basin-centered, fore-arc gravity lows might be good predictors of high seismic slip in future earthquakes. Since 2001, ten megathrust earthquakes have occurred with magnitudes greater than Mw 7.7, including the giant, Mw 9.17 Sumatra earthquake of 2004. These earthquakes provide a robust test of the idea that seismic slip is focused beneath basin-centered gravity lows, and also the related ideas that the landward maximum gravity gradient marks the effective down-dip limit of large coseismic slip, and that intrabasin, transverse gravity highs are areas of lower slip. A compilation of seismic and geodetic slip inversions for the post-2001 earthquakes and new analyses of slip for the great Antofagasta, Jalisco, and Peru events in 1995 and 1996 indicate that more than 80% of the high-slip areas occur beneath deep-sea terrace gravity lows (DSTL), and that half of the earthquake asperities lie beneath fore-arc basins or local gravity lows. The maximum gravity gradient along the landward margin of the deep-sea terrace may mark the point where thicker overlying crust and higher temperatures on the megathrust limit the down dip extent of stick-slip behavior. Onland analogues are the mountain front of the Himalaya, which approximately marks the down-dip limit of large coseismic slip along the Main Frontal Thrust, and the front of the Taiwan Central Ranges, which coincides with the limit of slip during the 1999 Chi-Chi earthquake (Mw 7.6). In the up dip direction, coseismic slip may be partitioned onto splay faults in the wedge, as occurred in the 1964 Alaska earthquake. The observed pattern of greater slip at depth beneath fore arc basins is consistent with partitioning of slip up

  11. Fractals and Forecasting in Earthquakes and Finance

    NASA Astrophysics Data System (ADS)

    Rundle, J. B.; Holliday, J. R.; Turcotte, D. L.

    2011-12-01

    It is now recognized that Benoit Mandelbrot's fractals play a critical role in describing a vast range of physical and social phenomena. Here we focus on two systems, earthquakes and finance. Since 1942, earthquakes have been characterized by the Gutenberg-Richter magnitude-frequency relation, which in more recent times is often written as a moment-frequency power law. A similar relation can be shown to hold for financial markets. Moreover, a recent New York Times article, titled "A Richter Scale for the Markets" [1] summarized the emerging viewpoint that stock market crashes can be described with similar ideas as large and great earthquakes. The idea that stock market crashes can be related in any way to earthquake phenomena has its roots in Mandelbrot's 1963 work on speculative prices in commodities markets such as cotton [2]. He pointed out that Gaussian statistics did not account for the excessive number of booms and busts that characterize such markets. Here we show that both earthquakes and financial crashes can both be described by a common Landau-Ginzburg-type free energy model, involving the presence of a classical limit of stability, or spinodal. These metastable systems are characterized by fractal statistics near the spinodal. For earthquakes, the independent ("order") parameter is the slip deficit along a fault, whereas for the financial markets, it is financial leverage in place. For financial markets, asset values play the role of a free energy. In both systems, a common set of techniques can be used to compute the probabilities of future earthquakes or crashes. In the case of financial models, the probabilities are closely related to implied volatility, an important component of Black-Scholes models for stock valuations. [2] B. Mandelbrot, The variation of certain speculative prices, J. Business, 36, 294 (1963)

  12. Spatial-Temporal Analysis of Social Media Data Related to Nepal Earthquake 2015

    NASA Astrophysics Data System (ADS)

    Thapa, L.

    2016-06-01

    Social Medias these days have become the instant communication platform to share anything; from personal feelings to the matter of public concern, these are the easiest and aphoristic way to deliver information among the mass. With the development of Web 2.0 technologies, more and more emphasis has been given to user input in the web; the concept of Geoweb is being visualized and in the recent years, social media like Twitter, Flicker are among the popular Location Based Social Medias with locational functionality enabled in them. Nepal faced devastating earthquake on 25 April, 2015 resulting in the loss of thousands of lives, destruction in the historical-archaeological sites and properties. Instant help was offered by many countries around the globe and even lots of NGOs, INGOs and people started the rescue operations immediately; concerned authorities and people used different communication medium like Frequency Modulation Stations, Television, and Social Medias over the World Wide Web to gather information associated with the Quake and to ease the rescue activities. They also initiated campaign in the Social Media to raise the funds and support the victims. Even the social medias like Facebook, Twitter, themselves announced the helping campaign to rebuild Nepal. In such scenario, this paper features the analysis of Twitter data containing hashtag related to Nepal Earthquake 2015 together with their temporal characteristics, when were the message generated, where were these from and how these spread spatially over the internet?

  13. Fear based Education or Curiosity based Education as an Example of Earthquake and Natural Disaster Education: Results of Statistical Study in Primary Schools in Istanbul-Turkey

    NASA Astrophysics Data System (ADS)

    Ozcep, T.; Ozcep, F.

    2012-04-01

    Natural disaster reduction focuses on the urgent need for prevention activities to reduce loss of life, damage to property, infrastructure and environment, and the social and economic disruption caused by natural hazards. One of the most important factors in reduction of the potential damage of earthquakes is trained manpower. To understanding the causes of earthquakes and other natural phenomena (landslides, avalanches, floods, volcanoes, etc.) is one of the pre-conditions to show a conscious behavior. The aim of the study is to analysis and to investigate, how earthquakes and other natural phenomena are perceived by the students and the possible consequences of this perception, and their effects of reducing earthquake damage. One of the crucial questions is that is our education system fear or curiosity based education system? Effects of the damages due to earthquakes have led to look like a fear subject. In fact, due to the results of the effects, the earthquakes are perceived scary phenomena. In the first stage of the project, the learning (or perception) levels of earthquakes and other natural disasters for the students of primary school are investigated with a survey. Aim of this survey study of earthquakes and other natural phenomena is that have the students fear based or curiosity based approaching to the earthquakes and other natural events. In the second stage of the project, the path obtained by the survey are evaluated with the statistical point of approach. A questionnaire associated with earthquakes and natural disasters are applied to primary school students (that total number of them is approximately 700 pupils) to measure the curiosity and/or fear levels. The questionnaire consists of 17 questions related to natural disasters. The questions are: "What is the Earthquake ?", "What is power behind earthquake?", "What is the mental response during the earthquake ?", "Did we take lesson from earthquake's results ?", "Are you afraid of earthquake

  14. 2001 Bhuj, India, earthquake engineering seismoscope recordings and Eastern North America ground-motion attenuation relations

    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.

  15. Diffusive Phenomena and the Austenite/Martensite Relative Stability in Cu-Based Shape-Memory Alloys

    NASA Astrophysics Data System (ADS)

    Pelegrina, J. L.; Yawny, A.; Sade, M.

    2018-03-01

    The main characteristic of martensitic phase transitions is the coordinate movement of the atoms which takes place athermally, without the contribution of diffusion during its occurrence. However, the impacts of diffusive phenomena on the relative stability between the phases involved and, consequently, on the associated transformation temperatures and functional properties can be significant. This is particularly evident in the case of Cu-based shape-memory alloys where atomic diffusion in both austenite and martensite metastable phases might occur even at room-temperature levels, giving rise to a variety of intensively studied phenomena. In the present study, the progresses made in the understanding of three selected diffusion-related effects of importance in Cu-Zn-Al and Cu-Al-Be alloys are reviewed. They are the after-quench retained disorder in the austenitic structure and its subsequent reordering, the stabilization of the martensite, and the effect of applied stress on the austenitic order. It is shown how the experimental results obtained from tests performed on single crystal material can be rationalized under the shed of a model developed to evaluate the variation of the relative stability between the phases in terms of atom pairs interchanges.

  16. Diffusive Phenomena and the Austenite/Martensite Relative Stability in Cu-Based Shape-Memory Alloys

    NASA Astrophysics Data System (ADS)

    Pelegrina, J. L.; Yawny, A.; Sade, M.

    2018-02-01

    The main characteristic of martensitic phase transitions is the coordinate movement of the atoms which takes place athermally, without the contribution of diffusion during its occurrence. However, the impacts of diffusive phenomena on the relative stability between the phases involved and, consequently, on the associated transformation temperatures and functional properties can be significant. This is particularly evident in the case of Cu-based shape-memory alloys where atomic diffusion in both austenite and martensite metastable phases might occur even at room-temperature levels, giving rise to a variety of intensively studied phenomena. In the present study, the progresses made in the understanding of three selected diffusion-related effects of importance in Cu-Zn-Al and Cu-Al-Be alloys are reviewed. They are the after-quench retained disorder in the austenitic structure and its subsequent reordering, the stabilization of the martensite, and the effect of applied stress on the austenitic order. It is shown how the experimental results obtained from tests performed on single crystal material can be rationalized under the shed of a model developed to evaluate the variation of the relative stability between the phases in terms of atom pairs interchanges.

  17. Ionospheric anomalies detected by ionosonde and possibly related to crustal earthquakes in Greece

    NASA Astrophysics Data System (ADS)

    Perrone, Loredana; De Santis, Angelo; Abbattista, Cristoforo; Alfonsi, Lucilla; Amoruso, Leonardo; Carbone, Marianna; Cesaroni, Claudio; Cianchini, Gianfranco; De Franceschi, Giorgiana; De Santis, Anna; Di Giovambattista, Rita; Marchetti, Dedalo; Pavòn-Carrasco, Francisco J.; Piscini, Alessandro; Spogli, Luca; Santoro, Francesca

    2018-03-01

    Ionosonde data and crustal earthquakes with magnitude M ≥ 6.0 observed in Greece during the 2003-2015 period were examined to check if the relationships obtained earlier between precursory ionospheric anomalies and earthquakes in Japan and central Italy are also valid for Greek earthquakes. The ionospheric anomalies are identified on the observed variations of the sporadic E-layer parameters (h'Es, foEs) and foF2 at the ionospheric station of Athens. The corresponding empirical relationships between the seismo-ionospheric disturbances and the earthquake magnitude and the epicentral distance are obtained and found to be similar to those previously published for other case studies. The large lead times found for the ionospheric anomalies occurrence may confirm a rather long earthquake preparation period. The possibility of using the relationships obtained for earthquake prediction is finally discussed.

  18. Media exposure related to the 2008 Sichuan Earthquake predicted probable PTSD among Chinese adolescents in Kunming, China: A longitudinal study.

    PubMed

    Yeung, Nelson C Y; Lau, Joseph T F; Yu, Nancy Xiaonan; Zhang, Jianping; Xu, Zhening; Choi, Kai Chow; Zhang, Qi; Mak, Winnie W S; Lui, Wacy W S

    2018-03-01

    This study examined the prevalence and the psychosocial predictors of probable PTSD among Chinese adolescents in Kunming (approximately 444 miles from the epicenter), China, who were indirectly exposed to the Sichuan Earthquake in 2008. Using a longitudinal study design, primary and secondary school students (N = 3577) in Kunming completed questionnaires at baseline (June 2008) and 6 months afterward (December 2008) in classroom settings. Participants' exposure to earthquake-related imagery and content, perceptions and emotional reactions related to the earthquake, and posttraumatic stress symptoms were measured. Univariate and forward stepwise multivariable logistic regression models were fit to identify significant predictors of probable PTSD at the 6-month follow-up. Prevalences of probable PTSD (with a Children's Revised Impact of Event Scale score ≥30) among the participants at baseline and 6-month follow-up were 16.9% and 11.1% respectively. In the multivariable analysis, those who were frequently exposed to distressful imagery had experienced at least two types of negative life events, perceived that teachers were distressed due to the earthquake, believed that the earthquake resulted from damages to the ecosystem, and felt apprehensive and emotionally disturbed due to the earthquake reported a higher risk of probable PTSD at 6-month follow-up (all ps < .05). Exposure to distressful media images, emotional responses, and disaster-related perceptions at baseline were found to be predictive of probable PTSD several months after indirect exposure to the event. Parents, teachers, and the mass media should be aware of the negative impacts of disaster-related media exposure on adolescents' psychological health. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  19. On the relation of earthquake stress drop and ground motion variability

    NASA Astrophysics Data System (ADS)

    Oth, Adrien; Miyake, Hiroe; Bindi, Dino

    2017-07-01

    One of the key parameters for earthquake source physics is stress drop since it can be directly linked to the spectral level of ground motion. Stress drop estimates from moment corner frequency analysis have been shown to be extremely variable, and this to a much larger degree than expected from the between-event ground motion variability. This discrepancy raises the question whether classically determined stress drop variability is too large, which would have significant consequences for seismic hazard analysis. We use a large high-quality data set from Japan with well-studied stress drop data to address this issue. Nonparametric and parametric reference ground motion models are derived, and the relation of between-event residuals for Japan Meteorological Agency equivalent seismic intensity and peak ground acceleration with stress drop is analyzed for crustal earthquakes. We find a clear correlation of the between-event residuals with stress drops estimates; however, while the island of Kyushu is characterized by substantially larger stress drops than Honshu, the between-event residuals do not reflect this observation, leading to the appearance of two event families with different stress drop levels yet similar range of between-event residuals. Both the within-family and between-family stress drop variations are larger than expected from the ground motion between-event variability. A systematic common analysis of these parameters holds the potential to provide important constraints on the relative robustness of different groups of data in the different parameter spaces and to improve our understanding on how much of the observed source parameter variability is likely to be true source physics variability.

  20. Precursory diffuse carbon dioxide degassing signature related to a 5.1 magnitude earthquake in El Salvador, Central America

    NASA Astrophysics Data System (ADS)

    Salazar, J. M. L.; Pérez, N. M.; Hernández, P. A.; Soriano, T.; Barahona, F.; Olmos, R.; Cartagena, R.; López, D. L.; Lima, R. N.; Melián, G.; Galindo, I.; Padrón, E.; Sumino, H.; Notsu, K.

    2002-12-01

    Anomalous changes in the diffuse emission of carbon dioxide have been observed before some of the aftershocks of the 13 February 2001 El Salvador earthquake (magnitude 6.6). A significant increase in soil CO 2 efflux was detected 8 days before a 5.1 magnitude earthquake on 8 May 2001 25 km away from the observation site. In addition, pre- and co-seismic CO 2 efflux variations have also been observed related to the onset of a seismic swarm beneath San Vicente volcano on May 2001. Strain changes and/or fluid pressure fluctuations prior to earthquakes in the crust are hypothesized to be responsible for the observed variations in gas efflux at the surface environment of San Vicente volcano.

  1. Regional patterns of earthquake-triggered landslides and their relation to ground motion

    NASA Astrophysics Data System (ADS)

    Meunier, Patrick; Hovius, Niels; Haines, A. John

    2007-10-01

    We have documented patterns of landsliding associated with large earthquakes on three thrust faults: the Northridge earthquake in California, Chi-Chi earthquake in Taiwan, and two earthquakes on the Ramu-Markham fault bounding the Finisterre Mountains of Papua New Guinea. In each case, landslide densities are shown to be greatest in the area of strongest ground acceleration and to decay with distance from the epicenter. In California and Taiwan, the density of co-seismic landslides is linearly and highly correlated with both the vertical and horizontal components of measured peak ground acceleration. Based on this observation, we derive an expression for the spatial variation of landslide density analogous with regional seismic attenuation laws. In its general form, this expression applies to our three examples, and we determine best fit values for individual cases. Our findings open a window on the construction of shake maps from geomorphic observations for earthquakes in non-instrumented regions.

  2. Disaster preparedness and response improvement: comparison of the 2010 Haiti earthquake-related diagnoses with baseline medical data.

    PubMed

    van Berlaer, Gerlant; Staes, Tom; Danschutter, Dirk; Ackermans, Ronald; Zannini, Stefano; Rossi, Gabriele; Buyl, Ronald; Gijs, Geert; Debacker, Michel; Hubloue, Ives

    2017-10-01

    Disaster medicine research generally lacks control groups. This study aims to describe categories of diagnoses encountered by the Belgian First Aid and Support Team after the 2010 Haiti earthquake and extract earthquake-related changes from comparison with comparable baseline data. The hypothesis is that besides earthquake-related trauma, medical problems emerge soon, questioning an appropriate composition of Foreign Medical Teams and Interagency Emergency Health Kits. Using a descriptive cohort study design, diagnoses of patients presenting to the Belgian field hospital were prospectively registered during 4 weeks after the earthquake and compared with those recorded similarly by Médecins Sans Frontières in the same area and time span in previous and later years. Of 7000 triaged postearthquake patients, 3500 were admitted, of whom 2795 were included and analysed. In the fortnight after the earthquake, 90% suffered from injury. In the following fortnight, medical diseases emerged, particularly respiratory (23%) and digestive (14%). More than 53% developed infections within 3 weeks after the event. Médecins Sans Frontières registered 6407 patients in 2009; 6033 in 2011; and 7300 in 2012. A comparison indicates that postearthquake patients suffered significantly less from violence, but more from wounds, respiratory, digestive and ophthalmological diseases. This is the first comparison of postearthquake diagnoses with baseline data. Within 2 weeks after the acute phase of an earthquake, respiratory, digestive and ophthalmological problems will emerge to the prejudice of trauma. This fact should be anticipated when composing Foreign Medical Teams and Interagency Emergency Health Kits to be sent to the disaster site.

  3. Long-term dynamics of hawaiian volcanoes inferred by large-scale relative relocations of earthquakes

    NASA Astrophysics Data System (ADS)

    Got, J.-L.; Okubo, P.

    2003-04-01

    We investigated the microseismicity recorded in an active volcano to infer information concerning the volcano structure and long-term dynamics, by using relative relocations and focal mechanisms of microearthquakes. 32000 earthquakes of Mauna Loa and Kilauea volcanoes were recorded by more than 8 stations of the Hawaiian Volcano Observatory seismic network between 1988 and 1999. We studied 17000 of these events and relocated more than 70% with an accuracy ranging from 10 to 500 meters. About 75% of these relocated events are located in the vicinity of subhorizontal decollement planes, at 8 to 11 km depth. However, the striking features revealed by these relocation results are steep south-east dipping fault planes working as reverse faults, clearly located below the decollement plane and which intersect it. If this decollement plane coincides with the pre-Mauna Loa seafloor, as hypothesized by numerous authors, such reverse faults rupture the pre-Mauna Loa oceanic crust. The weight of the volcano and pressure in the magma storage system are possible causes of these ruptures, fully compatible with the local stress tensor computed by Gillard et al. (1996). Reverse faults are suspected of producing scarps revealed by km-long horizontal slip-perpendicular lineations along the decollement surface, and therefore large-scale roughness, asperities and normal stress variations. These are capable of generating stick-slip, large magnitude earthquakes, the spatial microseismic pattern observed in the south flank of Kilauea volcano, and Hilina-type instabilities. Ruptures intersecting the decollement surface, causing its large-scale roughness, may be an important parameter controlling the growth of Hawaiian volcanoes. Are there more or less rough decollement planes existing near the base of other volcanoes, such as Piton de la Fournaise or Etna, and able to explain part of their deformation and seismicity ?

  4. Peptic Ulcers in Fukushima Prefecture Related to the Great East Japan Earthquake, Tsunami and Nuclear Accident

    PubMed Central

    Hikichi, Takuto; Sato, Masaki; Watanabe, Ko; Nakamura, Jun; Kikuchi, Hitomi; Ejiri, Yutaka; Ishihata, Ryoichi; Irisawa, Atsushi; Takahashi, Yuta; Saito, Hironobu; Takagi, Tadayuki; Suzuki, Rei; Sugimoto, Mitsuru; Konno, Naoki; Waragai, Yuichi; Asama, Hiroyuki; Takasumi, Mika; Sato, Yuki; Ohira, Hiromasa; Obara, Katsutoshi

    2017-01-01

    Objective Due to the Great East Japan Earthquake, which occurred in March 2011, many residents of Fukushima Prefecture were affected by a radiation accident in addition to suffering loss or damage from the earthquake and the subsequent tsunami. The aim of this study was to evaluate the actual condition of patients with peptic ulcers related to the disaster. Methods Patients with peptic ulcers at six hospitals in three different regions of Fukushima Prefecture during the two months following the disaster and the corresponding period of the year before and the year after the disaster were enrolled in this study. Changes by period and region in the number of esophagogastroduodenoscopy (EGD) examinations and the number of peptic ulcer patients were evaluated as the primary endpoints. Changes in the frequencies of hemorrhagic ulcers were evaluated by period and by region as secondary endpoints. Results The numbers of EGDs and peptic ulcer cases compared to the previous year decreased in 2011 and then increased in 2012. However, the ratio of hemorrhagic ulcers to peptic ulcers was higher in 2011 (51.9%) than in 2010 (38.1%) and 2012 (31.1%), and the 2011 hemorrhagic ulcer ratio was the highest at 63.6% in the coastal area. Regarding bleeding cases during 2011, the rate at 1 month after the disaster (64.1%) was higher than the rate at 2 months after the disaster (40.5%) (p=0.033). Conclusion The number of patients with peptic ulcers did not increase immediately following the disaster in Fukushima Prefecture. However, the rate of bleeding patients increased soon after the disaster, especially in the coastal area. PMID:29269647

  5. 30 CFR 250.192 - What reports and statistics must I submit relating to a hurricane, earthquake, or other natural...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What reports and statistics must I submit... statistics must I submit relating to a hurricane, earthquake, or other natural occurrence? (a) You must submit evacuation statistics to the Regional Supervisor for a natural occurrence, such as a hurricane, a...

  6. The role of asymmetric frontal cortical activity in emotion-related phenomena: a review and update.

    PubMed

    Harmon-Jones, Eddie; Gable, Philip A; Peterson, Carly K

    2010-07-01

    Conceptual and empirical approaches to the study of the role of asymmetric frontal cortical activity in emotional processes are reviewed. Although early research suggested that greater left than right frontal cortical activity was associated with positive affect, more recent research, primarily on anger, suggests that greater left than right frontal cortical activity is associated with approach motivation, which can be positive (e.g., enthusiasm) or negative in valence (e.g., anger). In addition to reviewing this research on anger, research on guilt, bipolar disorder, and various types of positive affect is reviewed with relation to their association with asymmetric frontal cortical activity. The reviewed research not only contributes to a more complete understanding of the emotive functions of asymmetric frontal cortical activity, but it also points to the importance of considering motivational direction as separate from affective valence in psychological models of emotional space. Copyright © 2009 Elsevier B.V. All rights reserved.

  7. Accommodation space, relative sea level, and the archiving of paleo-earthquakes along subduction zones

    Kelsey, Harvey M.; Engelhart, Simon E.; Pilarczyk, Jessica E.; Horton, Benjamin P.; Rubin, Charles; Daryono, Mudrik; Ismail, Nazli; Hawkes, Andrea D.; Bernhardt, Christopher E.; Cahill, Niamh

    2015-01-01

    The spatial variability of Holocene relative sea-level (RSL) change influences the capacities of coastal environments to accommodate a sedimentary record of paleoenvironmental change. In this study we couch a specific investigation in more general terms in order to demonstrate the applicability of the relative sea-level history approach to paleoseismic investigations. Using subsidence stratigraphy, we trace the different modes of coastal sedimentation over the course of time in the eastern Indian Ocean where RSL change evolved from rapidly rising to static from 8000 yr ago to present. Initially, the coastal sites from the Aceh, Sumatra, coastal plain, which are subject to repeated great earthquakes and tsunamis, built up a sedimentary sequence in response to a RSL rise of 1.4 mm/yr. The sequence found at 2 sites 8 km apart contained 3 soils of a mangrove origin (Rhizophora,Bruguiera/Ceriops, Avicennia pollen, and/or intertidal foraminifera) buried by sudden submergence related to coseismic subsidence and 6 tsunami sands that contain pristine subtidal and planktic foraminifera. After 3800 cal yr B.P. (years before A.D. 1950), sea level stabilized and remained such to the present. The stable relative sea level reduced accommodation space in the late Holocene, suggesting that the continued aggradation of the coastal plain was a consequence of periodic coastal inundation by tsunamis.

  8. State of the metal core in nanosecond exploding wires and related phenomena

    NASA Astrophysics Data System (ADS)

    Sarkisov, G. S.; Sasorov, P. V.; Struve, K. W.; McDaniel, D. H.

    2004-08-01

    Experiments show that an expanding metal wire core that results from a nanosecond electrical explosion in vacuum consists primarily of three different states: solid, microdrop, and gas-plasma. The state of the wire core depends both on the amount of energy deposited before the voltage breakdown and on the heating conditions. For small amounts of deposited energy (on the order of solid-stage enthalpy), the wire core remains in a solid state or is partially disintegrated. For a high level of deposited energy (more than vaporization energy) the wire core is in a gas-plasma state. For an intermediate level of deposited energy (more than melting but less than vaporization), the wire disintegrates into hot liquid microdrops or clusters of submicron size. For a wire core in the cluster state, interferometry demonstrates weak (or even absent) phaseshift. Light emission shows a "firework effect"—the long late-time radiation related to the emission by the expanding cylinder of hot microparticles. For the wire core in a gas-plasma state, interferometry demonstrates a large phaseshift and a fast reduction in light emission due to adiabatic cooling of the expanding wire core. The simulation of this firework effect agrees well with experimental data, assuming submicron size and a temperature approaching boiling for the expanded microparticles cylinder.

  9. Investigation of Pre-Earthquake Ionospheric Disturbances by 3D Tomographic Analysis

    NASA Astrophysics Data System (ADS)

    Yagmur, M.

    2016-12-01

    Ionospheric variations before earthquakes have been widely discussed phenomena in ionospheric studies. To clarify the source and mechanism of these phenomena is highly important for earthquake forecasting. To well understanding the mechanical and physical processes of pre-seismic Ionospheric anomalies that might be related even with Lithosphere-Atmosphere-Ionosphere-Magnetosphere Coupling, both statistical and 3D modeling analysis are needed. For these purpose, firstly we have investigated the relation between Ionospheric TEC Anomalies and potential source mechanisms such as space weather activity and lithospheric phenomena like positive surface electric charges. To distinguish their effects on Ionospheric TEC, we have focused on pre-seismically active days. Then, we analyzed the statistical data of 54 earthquakes that M≽6 between 2000 and 2013 as well as the 2011 Tohoku and the 2016 Kumamoto Earthquakes in Japan. By comparing TEC anomaly and Solar activity by Dst Index, we have found that 28 events that might be related with Earthquake activity. Following the statistical analysis, we also investigate the Lithospheric effect on TEC change on selected days. Among those days, we have chosen two case studies as the 2011 Tohoku and the 2016 Kumamoto Earthquakes to make 3D reconstructed images by utilizing 3D Tomography technique with Neural Networks. The results will be presented in our presentation. Keywords : Earthquake, 3D Ionospheric Tomography, Positive and Negative Anomaly, Geomagnetic Storm, Lithosphere

  10. Exploring high temperature phenomena related to post-detonation using an electric arc

    NASA Astrophysics Data System (ADS)

    Dai, Z. R.; Crowhurst, J. C.; Grant, C. D.; Knight, K. B.; Tang, V.; Chernov, A. A.; Cook, E. G.; Lotscher, J. P.; Hutcheon, I. D.

    2013-11-01

    We report a study of materials recovered from a uranium-containing plasma generated by an electric arc. The device used to generate the arc is capable of sustaining temperatures of an eV or higher for up to 100 μs. Samples took the form of a 4 μm-thick U238 film deposited onto 8 pairs of 17 μm-thick Cu electrodes supported on a 25 μm-thick Kapton backing and sandwiched between glass plates. Materials recovered from the glass plates and around the electrode tips after passage of an arc were characterized using scanning and transmission electron microscopy. Recovered materials included a variety of crystalline compounds (e.g., UO2, UC2, UCu5,) as well as mixtures of uranium and amorphous glass. Most of the materials collected on the glass plates took the form of spherules having a wide range of diameters from tens of nanometers to tens of micrometers. The composition and size of the spherules depended on location, indicating different chemical and physical environments. A theoretical analysis we have carried out suggests that the submicron spherules presumably formed by deposition during the arc discharge, while at the same time the glass plates were strongly heated due to absorption of plasma radiation mainly by islands of deposited metals (Cu, U). The surface temperature of the glass plates is expected to have risen to ˜2300 K thus producing a liquefied glass layer, likely diffusions of the deposited metals on the hot glass surface and into this layer were accompanied by chemical reactions that gave rise to the observed materials. These results, together with the compact scale and relatively low cost, suggest that the experimental technique provides a practical approach to investigate the complex physical and chemical processes that occur when actinide-containing material interacts with the environment at high temperature, for example, during fallout formation following a nuclear detonation.

  11. Ancient sandstone condition assessment in relation to degradation, cleaning and consolidation phenomena

    NASA Astrophysics Data System (ADS)

    Drdácký, Miloš; Frankeová, Dita; Slížková, Zuzana

    2015-04-01

    of cubes for non-destructive US tests and micro drilling. Then the cubes were cut into thin plates and they were tested for volumetric change due to hydric and temperature variations. That procedure allowed a comparison of results of the US tests on cubes and destructive bending tests on thin plates. The remains of these plates were used for porosity measurements. The overall test procedure was planned and carried out in a way which ensured testing of appropriately corresponding specimens. The results supplied data for studying efficiency of the consolidation treatment with silicic acid ester products in relation to three pre-treatment stone conditions, as well as to the type of sandstone cementation (the tested stones had mostly a kaolin or silica, rarely a goethit cementation). The tested stone types were documented by macroscopic and microscopic (thin section) descriptions. The results further indicate capacity of individual testing and assessment methods, and help to select methods suitable for in situ diagnostics.

  12. Developing a new perspective to study the health of survivors of Sichuan earthquakes in China: a study on the effect of post-earthquake rescue policies on survivors' health-related quality of life.

    PubMed

    Liang, Ying; Wang, Xiukun

    2013-10-29

    Sichuan is a province in China with an extensive history of earthquakes. Recent earthquakes, including the Lushan earthquake in 2013, have resulted in thousands of people losing their homes and their families. However, there is a research gap on the efficiency of government support policies. Therefore, this study develops a new perspective to study the health of earthquake survivors, based on the effect of post-earthquake rescue policies on health-related quality of life (HRQOL) of survivors of the Sichuan earthquake. This study uses data from a survey conducted in five hard-hit counties (Wenchuan, Qingchuan, Mianzhu, Lushan, and Dujiangyan) in Sichuan in 2013. A total of 2,000 questionnaires were distributed, and 1,672 were returned; the response rate was 83.6%. Results of the rescue policies scale and Medical Outcomes Study Short Form 36 (SF-36) scale passed the reliability test. The confirmatory factor analysis model showed that the physical component summary (PCS) directly affected the mental component summary (MCS). The results of structural equation model regarding the effects of rescue policies on HRQOL showed that the path coefficients of six policies (education, orphans, employment, poverty, legal, and social rescue policies) to the PCS of survivors were all positive and passed the test of significance. Finally, although only the path coefficient of the educational rescue policy to the MCS of survivors was positive and passed the test of significance, the other five policies affected the MCS indirectly through the PCS. The general HRQOL of survivors is not ideal; the survivors showed a low satisfaction with the post-earthquake rescue policies. Further, the six post-earthquake rescue policies significantly improved the HRQOL of survivors and directly affected the promotion of the PCS of survivors. Aside from the educational rescue policy, all other policies affected the MCS indirectly through the PCS. This finding indicates relatively large differences in

  13. Transport Phenomena.

    ERIC Educational Resources Information Center

    McCready, Mark J.; Leighton, David T.

    1987-01-01

    Discusses the problems created in graduate chemical engineering programs when students enter with a wide diversity of understandings of transport phenomena. Describes a two-semester graduate transport course sequence at the University of Notre Dame which focuses on fluid mechanics and heat and mass transfer. (TW)

  14. Earthquakes, September-October 1986

    Person, W.J.

    1987-01-01

    There was one great earthquake (8.0 and above) during this reporting period in the South Pacific in the Kermadec Islands. There were no major earthquakes (7.0-7.9) but earthquake-related deaths were reported in Greece and in El Salvador. There were no destrcutive earthquakes in the United States.

  15. Physics of Earthquake Disaster: From Crustal Rupture to Building Collapse

    NASA Astrophysics Data System (ADS)

    Uenishi, Koji

    2018-05-01

    Earthquakes of relatively greater magnitude may cause serious, sometimes unexpected failures of natural and human-made structures, either on the surface, underground, or even at sea. In this review, by treating several examples of extraordinary earthquake-related failures that range from the collapse of every second building in a commune to the initiation of spontaneous crustal rupture at depth, we consider the physical background behind the apparently abnormal earthquake disaster. Simple but rigorous dynamic analyses reveal that such seemingly unusual failures actually occurred for obvious reasons, which may remain unrecognized in part because in conventional seismic analyses only kinematic aspects of the effects of lower-frequency seismic waves below 1 Hz are normally considered. Instead of kinematics, some dynamic approach that takes into account the influence of higher-frequency components of waves over 1 Hz will be needed to anticipate and explain such extraordinary phenomena and mitigate the impact of earthquake disaster in the future.

  16. Relation between energy radiation ratio and rupture speed in numerically simulated earthquakes

    NASA Astrophysics Data System (ADS)

    Noda, H.; Lapusta, N.; Kanamori, H.

    2011-12-01

    One of the prominent questions in seismology is energy partitioning during an earthquake. Venkataraman and Kanamori [2004] discussed radiation ratio η_R, the ratio of radiated energy E_R to partial strain energy change ΔW_0 which is the total released strain energy minus the energy that would have been dissipated if a fault had slipped at the final stress. They found positive correlation between η_R and rupture speed in large earthquakes, and compared these data with theoretical estimates from simplified models. The relation between η_R and rupture speed is of great interest since both quantities can be estimated independently although there are large uncertainties. We conduct numerical simulations of dynamic ruptures and study the obtained energy partitioning (and η_R) and averaged rupture speeds V_r. So far, we have considered problems based on TPV103 from the SCEC/USGS Spontaneous Rupture Code Verification Project [Harris et al., 2009, http://scecdata.usc.edu/cvws/], which is a 3-D problem with the possibility of remarkable rate weakening at coseismic slip rates caused by flash heating of microscopic asperities [Rice, 1999]. We study the effect of background shear stress level τ_b and the manner in which rupture is arrested, either in rate-strengthening or unbreakable areas of the fault. Note that rupture speed at each fault point is defined when the rupture is still in progress, while η_R is defined after all dynamic processes such as propagation of a rupture front, healing fronts, and seismic waves have been completed. Those complexities may cause a difference from the theoretical estimates based on simple models, an issue we explore in this study. Overall, our simulations produce the relation between η_R and V_r broadly consistent with the study of Venkataraman and Kanamori (2004) for natural earthquakes and the corresponding theoretical estimates. The model by Mott [1948] agrees best with the cases studied so far, although it is not rigorously

  17. Empirical ground-motion relations for subduction-zone earthquakes and their application to Cascadia and other regions

    Atkinson, G.M.; Boore, D.M.

    2003-01-01

    Ground-motion relations for earthquakes that occur in subduction zones are an important input to seismic-hazard analyses in many parts of the world. In the Cascadia region (Washington, Oregon, northern California, and British Columbia), for example, there is a significant hazard from megathrust earthquakes along the subduction interface and from large events within the subducting slab. These hazards are in addition to the hazard from shallow earthquakes in the overlying crust. We have compiled a response spectra database from thousands of strong-motion recordings from events of moment magnitude (M) 5-8.3 occurring in subduction zones around the world, including both interface and in-slab events. The 2001 M 6.8 Nisqually and 1999 M 5.9 Satsop earthquakes are included in the database, as are many records from subduction zones in Japan (Kyoshin-Net data), Mexico (Guerrero data), and Central America. The size of the database is four times larger than that available for previous empirical regressions to determine ground-motion relations for subduction-zone earthquakes. The large dataset enables improved determination of attenuation parameters and magnitude scaling, for both interface and in-slab events. Soil response parameters are also better determined by the data. We use the database to develop global ground-motion relations for interface and in-slab earthquakes, using a maximum likelihood regression method. We analyze regional variability of ground-motion amplitudes across the global database and find that there are significant regional differences. In particular, amplitudes in Cascadia differ by more than a factor of 2 from those in Japan for the same magnitude, distance, event type, and National Earthquake Hazards Reduction Program (NEHRP) soil class. This is believed to be due to regional differences in the depth of the soil profile, which are not captured by the NEHRP site classification scheme. Regional correction factors to account for these differences are

  18. Ionospheric Anomalies Related to the (M = 7.3), August 27, 2012, Puerto Earthquake, (M = 6.8), August 30, 2012 Jan Mayen Island Earthquake, and (M = 7.6), August 31, 2012, Philippines Earthquake: Two-Dimensional Principal Component Analysis

    PubMed Central

    Lin, Jyh-Woei

    2013-01-01

    Two-dimensional principal component analysis (2DPCA) and principal component analysis (PCA) are used to examine the ionospheric total electron content (TEC) data during the time period from 00:00 on August 21 to 12: 45 on August 31 (UT), which are 10 days before the M = 7.6 Philippines earthquake at 12:47:34 on August 31, 2012 (UT) with the depth at 34.9 km. From the results by using 2DPCA, a TEC precursor of Philippines earthquake is found during the time period from 4:25 to 4:40 on August 28, 2012 (UT) with the duration time of at least 15 minutes. Another earthquake-related TEC anomaly is detectable for the time period from 04:35 to 04:40 on August 27, 2012 (UT) with the duration time of at least 5 minutes during the Puerto earthquake at 04: 37:20 on August 27, 2012 (UT) (M w = 7.3) with the depth at 20.3 km. The precursor of the Puerto earthquake is not detectable. TEC anomaly is not to be found related to the Jan Mayen Island earthquake (M w = 6.8) at 13:43:24 on August 30, 2012 (UT). These earthquake-related TEC anomalies are detectable by using 2DPCA rather than PCA. They are localized nearby the epicenters of the Philippines and Puerto earthquakes. PMID:23844386

  19. On relating apparent stress to the stress causing earthquake fault slip

    McGarr, A.

    1999-01-01

    Apparent stress ??a is defined as ??a = ??????, where ???? is the average shear stress loading the fault plane to cause slip and ?? is the seismic efficiency, defined as Ea/W, where Ea is the energy radiated seismically and W is the total energy released by the earthquake. The results of a recent study in which apparent stresses of mining-induced earthquakes were compared to those measured for laboratory stick-slip friction events led to the hypothesis that ??a/???? ??? 0.06. This hypothesis is tested here against a substantially augmented data set of earthquakes for which ???? can be estimated, mostly from in situ stress measurements, for comparison with ??a. The expanded data set, which includes earthquakes artificially triggered at a depth of 9 km in the German Kontinentales Tiefbohrprogramm der Bundesrepublik Deutschland (KTB) borehole and natural tectonic earthquakes, covers a broad range of hypocentral depths, rock types, pore pressures, and tectonic settings. Nonetheless, over ???14 orders of magnitude in seismic moment, apparent stresses exhibit distinct upper bounds defined by a maximum seismic efficiency of ???0.06, consistent with the hypothesis proposed before. This behavior of ??a and ?? can be expressed in terms of two parameters measured for stick-slip friction events in the laboratory: the ratio of the static to the dynamic coefficient of friction and the fault slip overshoot. Typical values for these two parameters yield seismic efficiencies of ???0.06. In contrast to efficiencies for laboratory events for which ?? is always near 0.06, those for earthquakes tend to be less than this bounding value because Ea for earthquakes is usually underestimated due to factors such as band-limited recording. Thus upper bounds on ??a/???? appear to be controlled by just a few fundamental aspects of frictional stick-slip behavior that are common to shallow earthquakes everywhere. Estimates of ???? from measurements of ??a for suites of earthquakes, using ??a

  20. Postearthquake relaxation and aftershock accumulation linearly related after the 2003 M 6.5 Chengkung, Taiwan, and the 2004 M 6.0 Parkfield, California, earthquakes

    Savage, J.C.; Yu, S.-B.

    2007-01-01

    We treat both the number of earthquakes and the deformation following a mainshock as the superposition of a steady background accumulation and the post-earthquake process. The preseismic displacement and seismicity rates ru and rE are used as estimates of the background rates. Let t be the time after the mainshock, u(t) + u0 the postseismic displacement less the background accumulation rut, and ??N(t) the observed cumulative number of postseismic earthquakes less the background accumulation rE t. For the first 160 days (duration limited by the occurrence of another nearby earthquake) following the Chengkung (M 6.5, 10 December 2003, eastern Taiwan) and the first 560 days following the Parkfield (M 6.0, 28 September 2004, central California) earthquakes u(t) + u0 is a linear function of ??N(t). The aftershock accumulation ??N(t) for both earthquakes is described by the modified Omori Law d??N/dt ?? (1 + t/??)-p with p = 0.96 and ?? = 0.03 days. Although the Chengkung earthquake involved sinistral, reverse slip on a moderately dipping fault and the Parkfield earthquake right-lateral slip on a near-vertical fault, the earthquakes share an unusual feature: both occurred on faults exhibiting interseismic fault creep at the surface. The source of the observed postseismic deformation appears to be afterslip on the coseismic rupture. The linear relation between u(t) + u0 and N(t) suggests that this afterslip also generates the aftershocks. The linear relation between u(t) + u0 and ??N(t) obtains after neither the 1999 M 7.1 Hector Mine (southern California) nor the 1999 M 7.6 Chi-Chi (central Taiwan) earthquakes, neither of which occurred on fault segments exhibiting fault creep.

  1. Experiences of possession and paranormal phenomena among women in the general population: are they related to traumatic stress and dissociation?

    PubMed

    Sar, Vedat; Alioğlu, Firdevs; Akyüz, Gamze

    2014-01-01

    This study sought to determine the prevalence of experiences of possession and paranormal phenomena (PNP) in the general population and their possible relations to each other and to traumatic stress and dissociation. The study was conducted on a representative female sample recruited from a town in central eastern Turkey. The Dissociative Disorders Interview Schedule, the posttraumatic stress disorder (PTSD) and borderline personality disorder sections of the Structured Clinical Interviews for DSM-IV Axis-I and Personality Disorders, and the Childhood Abuse and Neglect Questionnaire were administered to 628 women. Of these, 127 (20.2%) women reported at least 1 type of PNP and 13 (2.1%) women reported possession. Women with a dissociative disorder reported all types of possession and PNP (except telepathy) more frequently than those without. Whereas women with a trauma history in childhood and adulthood or PTSD reported possession more frequently than those without, PNP were associated with childhood trauma only. Factor analysis yielded 4 dimensions: possession by and/or contact with nonhuman entities, extrasensory communications, possession by a human entity, and precognition. These factors correlated with number of secondary features of dissociative identity disorder and Schneiderian symptoms. Latent class analysis identified 3 groups. The most traumatized group, with predominantly dissociative and trauma-related disorders, had the highest scores on all factors. Notwithstanding their presence in healthy individuals, possession and PNP were associated with trauma and dissociation in a subgroup of affected participants. Both types of experience seem to be normal human capacities of experiencing that may be involved in response to traumatic stress. Given the small numbers, this study should be considered preliminary.

  2. Brief Report: Reducing Earthquake-Related Fears in Victim and Nonvictim Children

    ERIC Educational Resources Information Center

    Karairmak, Ozlem; Aydin, GuL

    2008-01-01

    In this study, the authors investigated the fears of earthquake victim and nonvictim elementary school students and the effectiveness of an activity-based cognitive fear reduction (ABCF) procedure developed by the authors. To measure fear, the authors collected data from 266 participants using a modified version of the Fear Survey Schedule for…

  3. An interdisciplinary approach to study Pre-Earthquake processes

    NASA Astrophysics Data System (ADS)

    Ouzounov, D.; Pulinets, S. A.; Hattori, K.; Taylor, P. T.

    2017-12-01

    We will summarize a multi-year research effort on wide-ranging observations of pre-earthquake processes. Based on space and ground data we present some new results relevant to the existence of pre-earthquake signals. Over the past 15-20 years there has been a major revival of interest in pre-earthquake studies in Japan, Russia, China, EU, Taiwan and elsewhere. Recent large magnitude earthquakes in Asia and Europe have shown the importance of these various studies in the search for earthquake precursors either for forecasting or predictions. Some new results were obtained from modeling of the atmosphere-ionosphere connection and analyses of seismic records (foreshocks /aftershocks), geochemical, electromagnetic, and thermodynamic processes related to stress changes in the lithosphere, along with their statistical and physical validation. This cross - disciplinary approach could make an impact on our further understanding of the physics of earthquakes and the phenomena that precedes their energy release. We also present the potential impact of these interdisciplinary studies to earthquake predictability. A detail summary of our approach and that of several international researchers will be part of this session and will be subsequently published in a new AGU/Wiley volume. This book is part of the Geophysical Monograph series and is intended to show the variety of parameters seismic, atmospheric, geochemical and historical involved is this important field of research and will bring this knowledge and awareness to a broader geosciences community.

  4. From Multi-Sensors Observations Towards Cross-Disciplinary Study of Pre-Earthquake Signals. What have We Learned from the Tohoku Earthquake?

    NASA Technical Reports Server (NTRS)

    Ouzounov, D.; Pulinets, S.; Papadopoulos, G.; Kunitsyn, V.; Nesterov, I.; Hayakawa, M.; Mogi, K.; Hattori, K.; Kafatos, M.; Taylor, P.

    2012-01-01

    The lessons we have learned from the Great Tohoku EQ (Japan, 2011) how this knowledge will affect our future observation and analysis is the main focus of this presentation.We present multi-sensors observations and multidisciplinary research in our investigation of phenomena preceding major earthquakes. These observations revealed the existence of atmospheric and ionospheric phenomena occurring prior to theM9.0 Tohoku earthquake of March 11, 2011, which indicates s new evidence of a distinct coupling between the lithosphere and atmosphere/ionosphere, as related to underlying tectonic activity. Similar results have been reported before the catastrophic events in Chile (M8.8, 2010), Italy (M6.3, 2009) and Sumatra (M9.3, 2004). For the Tohoku earthquake, our analysis shows a synergy between several independent observations characterizing the state of the lithosphere /atmosphere coupling several days before the onset of the earthquakes, namely: (i) Foreshock sequence change (rate, space and time); (ii) Outgoing Long wave Radiation (OLR) measured at the top of the atmosphere; and (iii) Anomalous variations of ionospheric parameters revealed by multi-sensors observations. We are presenting a cross-disciplinary analysis of the observed pre-earthquake anomalies and will discuss current research in the detection of these signals in Japan. We expect that our analysis will shed light on the underlying physics of pre-earthquake signals associated with some of the largest earthquake events

  5. Empirical Scaling Relations of Source Parameters For The Earthquake Swarm 2000 At Novy Kostel (vogtland/nw-bohemia)

    NASA Astrophysics Data System (ADS)

    Heuer, B.; Plenefisch, T.; Seidl, D.; Klinge, K.

    Investigations on the interdependence of different source parameters are an impor- tant task to get more insight into the mechanics and dynamics of earthquake rup- ture, to model source processes and to make predictions for ground motion at the surface. The interdependencies, providing so-called scaling relations, have often been investigated for large earthquakes. However, they are not commonly determined for micro-earthquakes and swarm-earthquakes, especially for those of the Vogtland/NW- Bohemia region. For the most recent swarm in the Vogtland/NW-Bohemia, which took place between August and December 2000 near Novy Kostel (Czech Republic), we systematically determine the most important source parameters such as energy E0, seismic moment M0, local magnitude ML, fault length L, corner frequency fc and rise time r and build their interdependencies. The swarm of 2000 is well suited for such investigations since it covers a large magnitude interval (1.5 ML 3.7) and there are also observations in the near-field at several stations. In the present paper we mostly concentrate on two near-field stations with hypocentral distances between 11 and 13 km, namely WERN (Wernitzgrün) and SBG (Schönberg). Our data processing includes restitution to true ground displacement and rotation into the ray-based prin- cipal co-ordinate system, which we determine by the covariance matrix of the P- and S-displacement, respectively. Data preparation, determination of the distinct source parameters as well as statistical interpretation of the results will be exemplary pre- sented. The results will be discussed with respect to temporal variations in the swarm activity (the swarm consists of eight distinct sub-episodes) and already existing focal mechanisms.

  6. On Earthquake Prediction in Japan

    PubMed Central

    UYEDA, Seiya

    2013-01-01

    Japan’s National Project for Earthquake Prediction has been conducted since 1965 without success. An earthquake prediction should be a short-term prediction based on observable physical phenomena or precursors. The main reason of no success is the failure to capture precursors. Most of the financial resources and manpower of the National Project have been devoted to strengthening the seismographs networks, which are not generally effective for detecting precursors since many of precursors are non-seismic. The precursor research has never been supported appropriately because the project has always been run by a group of seismologists who, in the present author’s view, are mainly interested in securing funds for seismology — on pretense of prediction. After the 1995 Kobe disaster, the project decided to give up short-term prediction and this decision has been further fortified by the 2011 M9 Tohoku Mega-quake. On top of the National Project, there are other government projects, not formally but vaguely related to earthquake prediction, that consume many orders of magnitude more funds. They are also un-interested in short-term prediction. Financially, they are giants and the National Project is a dwarf. Thus, in Japan now, there is practically no support for short-term prediction research. Recently, however, substantial progress has been made in real short-term prediction by scientists of diverse disciplines. Some promising signs are also arising even from cooperation with private sectors. PMID:24213204

  7. Developing a new perspective to study the health of survivors of Sichuan earthquakes in China: a study on the effect of post-earthquake rescue policies on survivors’ health-related quality of life

    PubMed Central

    2013-01-01

    Background Sichuan is a province in China with an extensive history of earthquakes. Recent earthquakes, including the Lushan earthquake in 2013, have resulted in thousands of people losing their homes and their families. However, there is a research gap on the efficiency of government support policies. Therefore, this study develops a new perspective to study the health of earthquake survivors, based on the effect of post-earthquake rescue policies on health-related quality of life (HRQOL) of survivors of the Sichuan earthquake. Methods This study uses data from a survey conducted in five hard-hit counties (Wenchuan, Qingchuan, Mianzhu, Lushan, and Dujiangyan) in Sichuan in 2013. A total of 2,000 questionnaires were distributed, and 1,672 were returned; the response rate was 83.6%. Results Results of the rescue policies scale and Medical Outcomes Study Short Form 36 (SF-36) scale passed the reliability test. The confirmatory factor analysis model showed that the physical component summary (PCS) directly affected the mental component summary (MCS). The results of structural equation model regarding the effects of rescue policies on HRQOL showed that the path coefficients of six policies (education, orphans, employment, poverty, legal, and social rescue policies) to the PCS of survivors were all positive and passed the test of significance. Finally, although only the path coefficient of the educational rescue policy to the MCS of survivors was positive and passed the test of significance, the other five policies affected the MCS indirectly through the PCS. Conclusions The general HRQOL of survivors is not ideal; the survivors showed a low satisfaction with the post-earthquake rescue policies. Further, the six post-earthquake rescue policies significantly improved the HRQOL of survivors and directly affected the promotion of the PCS of survivors. Aside from the educational rescue policy, all other policies affected the MCS indirectly through the PCS. This finding

  8. Earthquakes, July-August 1991

    Person, W.J.

    1992-01-01

    There was one major earthquake during this reporting period-a magnitude 7.1 shock off the coast of Northern California on August 17. Earthquake-related deaths were reported from Indonesia, Romania, Peru, and Iraq. 

  9. Chance findings about early holocene tidal marshes of Grays Harbor, Washington, in relation to rapidly rising seas and great subduction earthquakes

    Phipps, James B.; Hemphill-Haley, Eileen; Atwater, Brian F.

    2015-06-18

    The puzzles posed by these findings include: (1) How did the marshes manage to endure centuries of relative sea-level rise that likely approached 1 cm/yr on average? (2) Did the marshes also endure subsidence that accompanied great thrust earthquakes on the Cascadia Subduction Zone? (3) Was their eventual drowning triggered by a Cascadia earthquake of unusually large size, or can the drowning be explained by sea-level rise that included a jump from drainage of glacial Lake Agassiz?

  10. Extending earthquakes' reach through cascading.

    PubMed

    Marsan, David; Lengliné, Olivier

    2008-02-22

    Earthquakes, whatever their size, can trigger other earthquakes. Mainshocks cause aftershocks to occur, which in turn activate their own local aftershock sequences, resulting in a cascade of triggering that extends the reach of the initial mainshock. A long-lasting difficulty is to determine which earthquakes are connected, either directly or indirectly. Here we show that this causal structure can be found probabilistically, with no a priori model nor parameterization. Large regional earthquakes are found to have a short direct influence in comparison to the overall aftershock sequence duration. Relative to these large mainshocks, small earthquakes collectively have a greater effect on triggering. Hence, cascade triggering is a key component in earthquake interactions.

  11. Effects of the New Madrid earthquake series in the Mississippi Alluvial Valley. Final report

    SciT

    Saucier, R.T.

    1977-02-01

    Geological effects of the New Madrid earthquake series of 1811-12 in the upper portion of the Lower Mississippi Valley include land subsidence, uplift or doming, landslides, bank caving, fissuring, and sand blow phenomena. Features resulting from the liquefaction of sand are widespread in the alluvial valley and offer the greatest potential for definitively assessing the effects of major earthquakes on thick alluvial deposits and predicting the recurrence interval of infrequent major earthquakes in the region. However, liquefaction phenomena have not been the subject of detailed geological investigations applying knowledge of alluvial morphology and earth sciences methodology. Comparative aerial photo interpretationmore » has been used to classify liquefaction phenomena according to morphology, distribution, and relationship to major depositional environments. Surface morphology and spatial distribution of sand blows and fissures indicate basic control by drainage lines, water table position, and thickness of fine-grained topstratum deposits, Research efforts have been aimed at locating field test sites where the subsurface expression of the liquefaction phenomena can be investigated through trenching and land planing. Subsurface expression is presumed to be more permanent than surface expression and may permit the recognition of such features in older formations. Evidence of fissures and related phenomena is being sought in older Quaternary deposits to permit estimates of the frequency of past major earthquakes.« less

  12. Studies related to the Charleston, South Carolina, earthquake of 1886; a preliminary report

    Rankin, Douglas W.

    1977-01-01

    PART A: The seismic history of the southeastern United States is dominated by the 1886 earthquake near Charleston, S.C. An understanding of the specific source and the uniqueness of the neotectonic setting of this large earthquake is essential in order to properly assess seismic hazards in the southeastern United States. Such knowledge will also contribute to the fundamental understanding of intraplate earthquakes and will aid indirectly in deciphering the evolution of Atlantic-type continental margins. The 15 chapters in this volume report on the first stage of an ongoing multidisciplinary study of the Charleston earthquake of 1886. The Modified Mercalli intensity for the 1886 earthquake was X in the meizoseismal area, an elliptical area 35 by 50 km, the center of which was Middleton Place. Seismic activity is continuing today in the Middleton Place-Summerville area at a higher level than prior to 1886. The present seismicity is originating at depths of 1 to 8 km, mostly in the crystalline basement beneath sedimentary rocks of the Coastal Plain. The crystalline basement beneath the Charleston-Summerville area is not simply a seaward extension of crystalline rocks of the Appalachian orogen that are exposed in the Piedmont to the northwest, but has a distinctive magnetic signature that does not reflect Appalachian orogenic trends. The area underlain by this distinctive geophysical basement, the Charleston block, may represent a broad zone of Triassic and (or) Jurassic crustal extension formed during the early stages of the opening of the Atlantic Ocean. The Charleston block is characterized in part by prominent, roughly circular magnetic and gravity highs that are thought to reflect maflc or ultramafic plutons. A continuously cored borehole put down over the shallowest (about 1.5 km deep) of these magnetic anomalies on the edge of the meizoseismal area bottomed at 792 m in amygdaloidal basalt. Although the K-Ar ages of about 100 m.y. for the basalt are consistent

  13. Relation of landslides triggered by the Kiholo Bay earthquake to modeled ground motion

    Harp, Edwin L.; Hartzell, Stephen H.; Jibson, Randall W.; Ramirez-Guzman, L.; Schmitt, Robert G.

    2014-01-01

    The 2006 Kiholo Bay, Hawaii, earthquake triggered high concentrations of rock falls and slides in the steep canyons of the Kohala Mountains along the north coast of Hawaii. Within these mountains and canyons a complex distribution of landslides was triggered by the earthquake shaking. In parts of the area, landslides were preferentially located on east‐facing slopes, whereas in other parts of the canyons no systematic pattern prevailed with respect to slope aspect or vertical position on the slopes. The geology within the canyons is homogeneous, so we hypothesize that the variable landslide distribution is the result of localized variation in ground shaking; therefore, we used a state‐of‐the‐art, high‐resolution ground‐motion simulation model to see if it could reproduce the landslide‐distribution patterns. We used a 3D finite‐element analysis to model earthquake shaking using a 10 m digital elevation model and slip on a finite‐fault model constructed from teleseismic records of the mainshock. Ground velocity time histories were calculated up to a frequency of 5 Hz. Dynamic shear strain also was calculated and compared with the landslide distribution. Results were mixed for the velocity simulations, with some areas showing correlation of landslide locations with peak modeled ground motions but many other areas showing no such correlation. Results were much improved for the comparison with dynamic shear strain. This suggests that (1) rock falls and slides are possibly triggered by higher frequency ground motions (velocities) than those in our simulations, (2) the ground‐motion velocity model needs more refinement, or (3) dynamic shear strain may be a more fundamental measurement of the decoupling process of slope materials during seismic shaking.

  14. Characterizing Mega-Earthquake Related Tsunami on Subduction Zones without Large Historical Events

    NASA Astrophysics Data System (ADS)

    Williams, C. R.; Lee, R.; Astill, S.; Farahani, R.; Wilson, P. S.; Mohammed, F.

    2014-12-01

    Due to recent large tsunami events (e.g., Chile 2010 and Japan 2011), the insurance industry is very aware of the importance of managing its exposure to tsunami risk. There are currently few tools available to help establish policies for managing and pricing tsunami risk globally. As a starting point and to help address this issue, Risk Management Solutions Inc. (RMS) is developing a global suite of tsunami inundation footprints. This dataset will include both representations of historical events as well as a series of M9 scenarios on subductions zones that have not historical generated mega earthquakes. The latter set is included to address concerns about the completeness of the historical record for mega earthquakes. This concern stems from the fact that the Tohoku Japan earthquake was considerably larger than had been observed in the historical record. Characterizing the source and rupture pattern for the subduction zones without historical events is a poorly constrained process. In many case, the subduction zones can be segmented based on changes in the characteristics of the subducting slab or major ridge systems. For this project, the unit sources from the NOAA propagation database are utilized to leverage the basin wide modeling included in this dataset. The length of the rupture is characterized based on subduction zone segmentation and the slip per unit source can be determined based on the event magnitude (i.e., M9) and moment balancing. As these events have not occurred historically, there is little to constrain the slip distribution. Sensitivity tests on the potential rupture pattern have been undertaken comparing uniform slip to higher shallow slip and tapered slip models. Subduction zones examined include the Makran Trench, the Lesser Antilles and the Hikurangi Trench. The ultimate goal is to create a series of tsunami footprints to help insurers understand their exposures at risk to tsunami inundation around the world.

  15. Aura phenomena during syncope.

    PubMed

    Benke, T; Hochleitner, M; Bauer, G

    1997-01-01

    We studied the frequency and clinical characteristics of aura phenomena in 60 patients with cardiac and 40 subjects with vasovagal syncopes. The majority (93%) of all syncope patients recalled having experienced an aura. Aura phenomena were similar in both groups and were mostly compound auras comprising epigastric, vertiginous, visual, or somatosensory experiences, but were more detailed in the noncardiac group. The localizing significance of auras preceding a syncope was generally poor. Although hard to distinguish from epileptic auras from their structure and shape, syncope-related auras lacked symptoms that are commonly reported after epileptic seizures such as tastes, smells, déjà vu phenomena, scenic visual perceptions, and speech impairments. A detailed anamnestic exploration of auras seems worthwhile in unexplained disorders of consciousness.

  16. Earthquakes, March-April, 1993

    Person, Waverly J.

    1993-01-01

    Worldwide, only one major earthquake (7.0earthquake, a magnitude 7.2 shock, struck the Santa Cruz Islands region in the South Pacific on March 6. Earthquake-related deaths occurred in the Fiji Islands, China, and Peru.

  17. Earthquakes, September-October 1991

    Person, W.J.

    1992-01-01

    There were two major earthquakes (7.0-7.9) during this reporting period. the first was in the Solomon Islands on October 14 and the second was in India on October 19. Earthquake-related deaths were reported in Guatemala and India. Htere were no significant earthquakes in the United States during the period covered in this report. 

  18. Ground uplift related to permeability enhancement following the 2011 Tohoku earthquake in the Kanto Plain, Japan

    NASA Astrophysics Data System (ADS)

    Ishitsuka, Kazuya; Matsuoka, Toshifumi; Nishimura, Takuya; Tsuji, Takeshi; ElGharbawi, Tamer

    2017-06-01

    We investigated the post-seismic surface displacement of the 2011 Tohoku earthquake around the Kanto Plain (including the capital area of Japan), which is located approximately 400 km from the epicenter, using a global positioning system network during 2005-2015 and persistent scatterer interferometry of TerraSAR-X data from March 2011 to November 2012. Uniform uplift owing to viscoelastic relaxation and afterslip on the plain has been reported previously. In addition to the general trend, we identified areas where the surface displacement velocity was faster than the surrounding areas, as much as 7 mm/year for 3 years after the earthquake and with a velocity decay over time. Local uplift areas were 30 × 50 km2 and showed a complex spatial distribution with an irregular shape. Based on an observed groundwater level increase, we deduce that the local ground uplift was induced by a permeability enhancement and a pore pressure increase in the aquifer system, which is attributable to mainshock vibration.[Figure not available: see fulltext.

  19. Geologic structures related to New Madrid earthquakes near Memphis, Tennessee, based on gravity and magnetic interpretations

    Hildenbrand, T.G.; Stuart, W.D.; Talwani, P.

    2001-01-01

    New inversions of gravity and magnetic data in the region north of memphis. Tennessee, and south of latitude 36?? define boundaries of regional structures and igneous complexes in the upper crust. Microseismicity patterns near interpreted boundaries suggest that igneous complexes influence the locations of microseismicity. A weak seismicity cluster occurs near one intrusion (Covington pluton), at the intersection of the southwest margin of the Missouri batholith and the southeast margin of the Reelfoot rift. A narrow seismicity trend along the Reelfoot rift axis becomes diffuse near a second intrusion (Osceola intrusive complex) and changes direction to an area along the northwest flank of the intrusion. The axial seismicity trend also contains a tight cluster of earthquakes located just outside the Osceola intrusive complex. The mechanical explanation of the two seismicity patterns is uncertain, but the first cluster may be caused by stress concentration due to the high elastic stiffness and strength of the Covington intrusion. The spatially changing seismicity pattern near the Osceola complex may be caused by the preceding factors plus interaction with faulting along the rift axis. The axial seismicity strand itself is one of several connected and interacting active strands that may produce stress concentrations at strand ends and junctions. The microseismicity clusters at the peripheries of the two intrusions lead us to conclude that these stress concentrations or stressed volumes may be locations of future moderate to large earthquakes near Memphis. Published by Elsevier Science B.V.

  20. Data mining of atmospheric parameters associated with coastal earthquakes

    NASA Astrophysics Data System (ADS)

    Cervone, Guido

    Earthquakes are natural hazards that pose a serious threat to society and the environment. A single earthquake can claim thousands of lives, cause damages for billions of dollars, destroy natural landmarks and render large territories uninhabitable. Studying earthquakes and the processes that govern their occurrence, is of fundamental importance to protect lives, properties and the environment. Recent studies have shown that anomalous changes in land, ocean and atmospheric parameters occur prior to earthquakes. The present dissertation introduces an innovative methodology and its implementation to identify anomalous changes in atmospheric parameters associated with large coastal earthquakes. Possible geophysical mechanisms are discussed in view of the close interaction between the lithosphere, the hydrosphere and the atmosphere. The proposed methodology is a multi strategy data mining approach which combines wavelet transformations, evolutionary algorithms, and statistical analysis of atmospheric data to analyze possible precursory signals. One dimensional wavelet transformations and statistical tests are employed to identify significant singularities in the data, which may correspond to anomalous peaks due to the earthquake preparatory processes. Evolutionary algorithms and other localized search strategies are used to analyze the spatial and temporal continuity of the anomalies detected over a large area (about 2000 km2), to discriminate signals that are most likely associated with earthquakes from those due to other, mostly atmospheric, phenomena. Only statistically significant singularities occurring within a very short time of each other, and which tract a rigorous geometrical path related to the geological properties of the epicentral area, are considered to be associated with a seismic event. A program called CQuake was developed to implement and validate the proposed methodology. CQuake is a fully automated, real time semi-operational system, developed to

  1. Geochemical variation of groundwater in the Abruzzi region: earthquakes related signals?

    NASA Astrophysics Data System (ADS)

    Cardellini, C.; Chiodini, G.; Caliro, S.; Frondini, F.; Avino, R.; Minopoli, C.; Morgantini, N.

    2009-12-01

    The presence of a deep and inorganic source of CO2 has been recently recognized in Italy on the basis of the deeply derived carbon dissolved in the groundwater. In particular, the regional map of CO2 Earth degassing shows that two large degassing structures affect the Tyrrhenian side of the Italian peninsula. The northern degassing structure (TRDS, Tuscan Roman degassing structure) includes Tuscany, Latium and part of Umbria regions (~30000 km2) and releases > 6.1 Mt/y of deeply derived CO2. The southern degassing structure (CDS, Campanian degassing structure) affects the Campania region (~10000 km2) and releases > 3.1 Mt/y of deeply derived CO2. The total CO2 released by TRDS and CDS (> 9.2 Mt/y) is globally significant, being ~10% of the estimated present-day total CO2 discharge from sub aerial volcanoes of the Earth. The comparison between the map of CO2 Earth degassing and of the location of the Italian earthquakes highlights that the anomalous CO2 flux suddenly disappears in the Apennine in correspondence of a narrow band where most of the seismicity concentrates. A previous conceptual model proposed that in this area, at the eastern borders of TRDS and CDS plumes, the CO2 from the mantle wedge intrudes the crust and accumulate in structural traps generating over-pressurized reservoirs. These CO2 over-pressurized levels can play a major role in triggering the Apennine earthquakes, by reducing fault strength and potentially controlling the nucleation, arrest, and recurrence of both micro and major (M>5) earthquakes. The 2009 Abruzzo earthquakes, like previous seismic crises in the Northern Apennine, occurred at the border of the TRDS, suggesting also in this case a possible role played by deeply derived fluids in the earthquake generation. In order to investigate this process, detailed hydro-geochemical campaigns started immediately after the main shock of the 6th of April 2009. The surveys include the main springs of the area which were previously studied in

  2. The Study of Tone and Related Phenomena in an Amazonian Tone Language: Gavião of Rondônia

    ERIC Educational Resources Information Center

    Moore, Denny; Meyer, Julien

    2014-01-01

    This paper describes the methods used to study the tone and some related phenomena of the language of the Gavião of Rondônia, Brazil, which is part of the Mondé branch of the Tupi family. Whistling of words by indigenous informants was discovered to be a very effective method for obtaining phonetic accuracy in tone and length. Methods were devised…

  3. Preseismic Changes of the Level and Temperature of Confined Groundwater related to the 2011 Tohoku Earthquake

    PubMed Central

    Orihara, Yoshiaki; Kamogawa, Masashi; Nagao, Toshiyasu

    2014-01-01

    Anomalous groundwater changes started three months before the 2011 M9.0 Off the Pacific coast of the Tohoku Earthquake (Tohoku EQ), Japan. Groundwater level and temperature decreased almost simultaneously in a 2000-m well at a spa, Goyo-onsen, in Iwate Prefecture, 155 km northwest of the epicenter. Since the source of Goyo-onsen, located above the edge of a coseismic rupture area of the Tohoku EQ fault, is probably confined, the observed anomalies were caused probably by preseismic crustal deformation. Preseismic groundwater anomalies have been observed prior to similar large subduction EQs such as the 1946 M8.1 Nankai EQ. Thus, monitoring confined groundwater may be useful to identify precursors of large subduction EQs. PMID:25366123

  4. Anomalous chemical changes in well waters and possible relation to earthquakes

    NASA Astrophysics Data System (ADS)

    King, Chi-Yu; Evans, William C.; Presser, Theresa; Husk, Robert H.

    Water level, temperature, salinity, electric conductivity, and pH have been measured periodically for several years at three water wells located along a 17-km segment of the San Andreas fault between San Juan Bautista and Cienega Winery in central California. Water samples were collected at the same time for subsequent chemical analyses in the laboratory. Some sudden large changes in salinity and conductivity were recorded in early March 1980 at the two wells near San Juan Bautista. These changes coincided approximately with the beginning of an episode of increased local seismicity, including a magnitude 4.8 earthquake on April 13. Analyses of water samples revealed corresponding changes in ion concentrations, especially of Na+, Ca++, Mg++, SO4--, HCO3-, F-, and Cl-. The observed changes may be the result of mixing of waters from different aquifers through cracks developed in the water barriers by a possible crustal strain episode that may have occurred in the study area.

  5. Relating stress models of magma emplacement to volcano-tectonic earthquakes

    NASA Astrophysics Data System (ADS)

    Vargas-Bracamontes, D.; Neuberg, J.

    2007-12-01

    Among the various types of seismic signals linked to volcanic processes, volcano-tectonic earthquakes are probably the earliest precursors of volcanic eruptions. Understanding their relationship with magma emplacement can provide insight into the mechanisms of magma transport at depth and assist in the ultimate goal of forecasting eruptions. Volcano-tectonic events have been observed to occur on faults that experience increases in Coulomb stress changes as the result of magma intrusions. To simulate stress changes associated with magmatic injections, we test different models of volcanic sources in an elastic half-space. For each source model, we look at several aspects that influence the stress conditions of the magmatic system such as the regional tectonic setting, the effect of varying the elastic parameters of the media, the evolution of the magma with time, as well as the volume and rheology of the ascending magma.

  6. Investigations related to scientific deep drilling to study reservoir-triggered earthquakes at Koyna, India

    NASA Astrophysics Data System (ADS)

    Gupta, Harsh; Purnachandra Rao, N.; Roy, Sukanta; Arora, Kusumita; Tiwari, V. M.; Patro, Prasanta K.; Satyanarayana, H. V. S.; Shashidhar, D.; Mallika, K.; Akkiraju, Vyasulu V.; Goswami, Deepjyoti; Vyas, Digant; Ravi, G.; Srinivas, K. N. S. S. S.; Srihari, M.; Mishra, S.; Dubey, C. P.; Raju, D. Ch. V.; Borah, Ujjal; Chinna Reddy, K.; Babu, Narendra; Rohilla, Sunil; Dhar, Upasana; Sen, Mrinal; Bhaskar Rao, Y. J.; Bansal, B. K.; Nayak, Shailesh

    2015-09-01

    Artificial water reservoir-triggered earthquakes have continued at Koyna in the Deccan Traps province, India, since the impoundment of the Shivaji Sagar reservoir in 1962. Existing models, to comprehend the genesis of triggered earthquakes, suffer from lack of observations in the near field. To investigate further, scientific deep drilling and setting up a fault zone observatory at depth of 5-7 km is planned in the Koyna area. Prior to undertaking deep drilling, an exploratory phase of investigations has been launched to constrain subsurface geology, structure and heat flow regime in the area that provide critical inputs for the design of the deep borehole observatory. Two core boreholes drilled to depths of 1,522 and 1,196 m have penetrated the Deccan Traps and sampled the granitic basement in the region for the first time. Studies on cores provide new and direct information regarding the thickness of the Deccan Traps, the absence of infra-Trappean sediments and the nature of the underlying basement rocks. Temperatures estimated at a depth of 6 km in the area, made on the basis of heat flow and thermal properties data sets, do not exceed 150 °C. Low-elevation airborne gravity gradient and magnetic data sets covering 5,012 line km, together with high-quality magnetotelluric data at 100 stations, provide both regional information about the thickness of the Deccan Traps and the occurrence of localized density heterogeneities and anomalous conductive zones in the vicinity of the hypocentral zone. Acquisition of airborne LiDAR data to obtain a high-resolution topographic model of the region has been completed over an area of 1,064 km2 centred on the Koyna seismic zone. Seismometers have been deployed in the granitic basement inside two boreholes and are planned in another set of six boreholes to obtain accurate hypocentral locations and constrain the disposition of fault zones.

  7. Earthquake Emergency Education in Dushanbe, Tajikistan

    ERIC Educational Resources Information Center

    Mohadjer, Solmaz; Bendick, Rebecca; Halvorson, Sarah J.; Saydullaev, Umed; Hojiboev, Orifjon; Stickler, Christine; Adam, Zachary R.

    2010-01-01

    We developed a middle school earthquake science and hazards curriculum to promote earthquake awareness to students in the Central Asian country of Tajikistan. These materials include pre- and post-assessment activities, six science activities describing physical processes related to earthquakes, five activities on earthquake hazards and mitigation…

  8. Rupture, waves and earthquakes.

    PubMed

    Uenishi, Koji

    2017-01-01

    Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but "extraordinary" phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable.

  9. Rupture, waves and earthquakes

    PubMed Central

    UENISHI, Koji

    2017-01-01

    Normally, an earthquake is considered as a phenomenon of wave energy radiation by rupture (fracture) of solid Earth. However, the physics of dynamic process around seismic sources, which may play a crucial role in the occurrence of earthquakes and generation of strong waves, has not been fully understood yet. Instead, much of former investigation in seismology evaluated earthquake characteristics in terms of kinematics that does not directly treat such dynamic aspects and usually excludes the influence of high-frequency wave components over 1 Hz. There are countless valuable research outcomes obtained through this kinematics-based approach, but “extraordinary” phenomena that are difficult to be explained by this conventional description have been found, for instance, on the occasion of the 1995 Hyogo-ken Nanbu, Japan, earthquake, and more detailed study on rupture and wave dynamics, namely, possible mechanical characteristics of (1) rupture development around seismic sources, (2) earthquake-induced structural failures and (3) wave interaction that connects rupture (1) and failures (2), would be indispensable. PMID:28077808

  10. Teaching Optical Phenomena with Tracker

    ERIC Educational Resources Information Center

    Rodrigues, M.; Carvalho, P. Simeão

    2014-01-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a…

  11. Mental Health Distress and Related Factors Among Prefectural Public Servants Seven Months After the Great East Japan Earthquake

    PubMed Central

    Suzuki, Yuriko; Fukasawa, Maiko; Obara, Akiko; Kim, Yoshiharu

    2014-01-01

    Background To develop an empirically informed support measure for workers, we examined mental health distress and its risk factors among prefectural public servants who were affected by the Great East Japan Earthquake and faced a demanding workload in the midterm of the disaster. Methods We conducted a self-administered health survey of all public servants in the Miyagi prefectural government two and seven months after the Great East Japan Earthquake (3743 workers, 70.6% of all employees). We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for mental distress (defined as K6 score ≥10) in the domain of disaster-work-related stressors, work-related stressors, and disaster-related stressors. Results Among those with better levels of workplace communication, the only factor that increased the risk of mental distress was not taking a non-work day each week (adjusted OR 2.55, 95% CI 1.27–5.14). Among those with poorer levels of workplace communication, in addition to not taking a non-work day each week (adjusted OR 3.93, 95% CI 3.00–5.15), handling residents’ complaints (adjusted OR 1.55, 95% CI 1.00–2.42), having dead or missing family members (adjusted OR 2.87, 95% CI 1.53–5.38), and living in a shelter more than two months after the disaster (adjusted OR 2.80, 95% CI 1.32–5.95) increased the risk of mental distress. Conclusions All workers should be encouraged to take a non-work day each week. Among workers with poor workplace communication, special attention should be given to those who handle residents’ complaints, have lost a family member(s), and are living in a shelter for a prolonged period of time. PMID:24857952

  12. Modeling crustal deformation and rupture processes related to upwelling of deep CO2-rich fluids during the 1965-1967 Matsushiro Earthquake Swarm in Japan

    SciT

    Cappa, F.; Rutqvist, J.; Yamamoto, K.

    2009-05-15

    In Matsushiro, central Japan, a series of more than 700,000 earthquakes occurred over a 2-year period (1965-1967) associated with a strike-slip faulting sequence. This swarm of earthquakes resulted in ground surface deformations, cracking of the topsoil, and enhanced spring-outflows with changes in chemical compositions as well as carbon dioxide (CO{sub 2}) degassing. Previous investigations of the Matsushiro earthquake swarm have suggested that migration of underground water and/or magma may have had a strong influence on the swarm activity. In this study, employing coupled multiphase flow and geomechanical modelling, we show that observed crustal deformations and seismicity can have been drivenmore » by upwelling of deep CO{sub 2}-rich fluids around the intersection of two fault zones - the regional East Nagano earthquake fault and the conjugate Matsushiro fault. We show that the observed spatial evolution of seismicity along the two faults and magnitudes surface uplift, are convincingly explained by a few MPa of pressurization from the upwelling fluid within the critically stressed crust - a crust under a strike-slip stress regime near the frictional strength limit. Our analysis indicates that the most important cause for triggering of seismicity during the Matsushiro swarm was the fluid pressurization with the associated reduction in effective stress and strength in fault segments that were initially near critically stressed for shear failure. Moreover, our analysis indicates that a two order of magnitude permeability enhancement in ruptured fault segments may be necessary to match the observed time evolution of surface uplift. We conclude that our hydromechanical modelling study of the Matsushiro earthquake swarm shows a clear connection between earthquake rupture, deformation, stress, and permeability changes, as well as large-scale fluid flow related to degassing of CO{sub 2} in the shallow seismogenic crust. Thus, our study provides further evidence of

  13. Mental Health and Related Factors after the Great East Japan Earthquake and Tsunami

    PubMed Central

    Yokoyama, Yukari; Otsuka, Kotaro; Kawakami, Norito; Kobayashi, Seiichiro; Ogawa, Akira; Tannno, Kozo; Onoda, Toshiyuki; Yaegashi, Yumi; Sakata, Kiyomi

    2014-01-01

    Mental health is one of the most important issues facing disaster survivors. The purpose of this study is to determine the prevalence and correlates of mental health problems in survivors of the Great East Japan Earthquake and Tsunami at 6–11 months after the disaster. The questionnaire and notification were sent to the survivors in three municipalities in the Tohoku area of the Northern part of Honshu, Japan’s largest island, between September 2011 and February 2012. Questionnaires were sent to 12,772, 11,411, and 18,648 residents in the Yamada, Otsuchi, and Rikuzentakata municipalities, respectively. Residents were asked to bring the completed questionnaires to their health check-ups. A total of 11,124 or (26.0%) of them underwent health check-ups, and 10,198 were enrolled. We excluded 179 for whom a K6 score was missing and two who were both 17 years of age, which left 10,025 study participants (3,934 male and 6,091 female, mean age 61.0 years). K6 was used to measure mental health problems. The respondents were classified into moderate (5–12 of K6) and serious mental health problems (13+). A total of 42.6% of the respondents had moderate or serious mental health problems. Multivariate analysis showed that women were significantly associated with mental health problems. Other variables associated with mental health problems were: younger male, health complaints, severe economic status, relocations, and lack of a social network. An interaction effect of sex and economic status on severe mental health problems was statistically significant. Our findings suggest that mental health problems were prevalent in survivors of the Great East Japan Earthquake and Tsunami. For men and women, health complaints, severe economic status, relocations, and lack of social network may be important risk factors of poor mental health. For men, interventions focusing on economic support may be particularly useful in reducing mental health problems after the disaster. PMID

  14. AURORAL X-RAYS, COSMIC RAYS, AND RELATED PHENOMENA DURING THE STORM OF FEBRUARY 10-11, 1958

    SciT

    Winckler, J.R.; Peterson, L.; Hoffman, R.

    1959-06-01

    Balloon observations were made during the auroral storm of February 10- 11, 1958, at Minneapolis. Strong x-ray bursts in two groups were detected. The groups appeared coincident with two large magnetic bays, with strong radio noise absorption, and with the passage across the zenith of a very large amount of auroral luminosity. From the x-ray intensity and measured energies, an electron current of 0.6 x 10/sup 6/ electrons /cm/sup 2// scc was present. These electrons ionizing the upper D layer accounted for the increased cosmic noise absorption. The x-rays themselves carried 1000 times less energy than the electrons and couldmore » not provide sufficient ionization for the observed radio absorption. Visual auroral fornis during this storm are reported to have lower borders at thc 200 to 300 km level. There is thus a difficulty in bringing the electrons to the D layer without ani accompanying visible aurora. A cosmic-ray decrease accompanied the storm and was observed to be from 4 to 6% at sea level, 21% in the balloon altitude ionization, and 15% in total energy influx at 55 deg geomagnetic latitude. Compared with the great intensity of the magnetic and auroral phenomena in this storm, the cosmic-ray modulation was not exceptionally large. (auth)« less

  15. Earthquakes; March-April 1975

    Person, W.J.

    1975-01-01

    There were no major earthquakes (magnitude 7.0-7.9) in March or April; however, there were earthquake fatalities in Chile, Iran, and Venezuela and approximately 35 earthquake-related injuries were reported around the world. In the United States a magnitude 6.0 earthquake struck the Idaho-Utah border region. Damage was estimated at about a million dollars. The shock was felt over a wide area and was the largest to hit the continental Untied States since the San Fernando earthquake of February 1971. 

  16. Psychosocial factors affecting resilience in Nepalese individuals with earthquake-related spinal cord injury: a cross-sectional study.

    PubMed

    Bhattarai, Muna; Maneewat, Khomapak; Sae-Sia, Wipa

    2018-03-02

    One of many types of injuries following an earthquake is spinal cord injury (SCI) which is a life-long medically complex injury and high-cost health problem. Despite several negative consequences, some persons with SCI are resilient enough to achieve positive adjustment, greater acceptance, and better quality of life. Since resilience is influenced by several factors and can vary by context, it is beneficial to explore factors that affect the resilience of people who sustained spinal cord injury from the 2015 earthquake in Nepal. A descriptive cross-sectional study included 82 participants from the Spinal Injury Rehabilitation Center and communities in Nepal. Participants completed the Demographic and Injury-related Questionnaire, Connor-Davidson Resilience Scale, Multidimensional Scale of Perceived Social Support, Moorong Self-efficacy Scale, Intrinsic Spirituality Scale, and Patient Health Questionnaire-9. Pearson's correlation and point biserial correlation analyses were performed to examine associations between resilience and independent variables. A hierarchical regression analysis was used to identify the influence of certain factors. Findings indicated significant associations between resilience and social support (r = 0.42, p < 0.001), self-efficacy (r = 0.53, p < 0.001), depressive mood (r = - 0.50, p < 0.001) and demographic variables which included sex (r = 0.47, p < 0.001), employment (r = 0.27, p = 0.016), and current living location (r = 0.24, p = 0.029). There was a non-significant association between resilience and spirituality (r = - 0.12, p > 0.05). In hierarchical regression analysis, an overall regression model explained 46% of the variance in resilience. Self-efficacy (β = 0.28, p = 0.007) and depressive mood (β = - 0.24, p = 0.016) significantly determined resilience after controlling the effect of demographic variables. Among the demographic factors, being male

  17. Aftershock Seismicity of the 27 February 2010 Maule Earthquake and its Relation to Postseismic Displacements from GPS

    NASA Astrophysics Data System (ADS)

    Lange, D.; Moreno, M. S.; Tilmann, F. J.; Baez, J.; Barrientos, S. E.; Beck, S. L.; Bernard, P.; Bevis, M. G.; Brooks, B. A.; Contreras Reyes, E.; Heit, B.; Methe, P.; Tassara, A.; Vilotte, J.; Vigny, C.

    2011-12-01

    On 27 February 2010 the Mw 8.8 Maule earthquake in Central Chile ruptured a seismic gap where significant strain had accumulated since 1835. Shortly after the mainshock a dense network of temporary seismic landstations was installed along the whole rupture zone in order to capture the aftershock activity. We present the aftershock distribution and first motion polarity focal mechanisms based on automatic detection algorithms and picking engines. Processing the seismic data between 15 March and 30 September 2010 from stations from IRIS, IPGP, Caltech and GFZ, we determined 19,908~hypocentres with magnitudes Mw between 1 and 6.2. Seismic activity occurs in six groups: 1.) Normal faulting outer rise events 2.) A shallow group of plate interface seismicity apparent at 25-35 km depth and 50-120 km distance to the trench. Along strike, the aftershocks occur largely within the zone of co-seismic slip but extend ~50 km further north. Along dip, the events are either within the zone of co-seismic slip, or downdip from it, depending on the slip model used. 3.) A third band of seismicity is observed further downdip at 40-50 km depth and further inland at 150-160 km trench perpendicular distance, with mostly shallow dipping thrust focal mechanisms indicating rupture of the plate interface significantly downdip of the co-seismic rupture, and presumably above the intersection of the continental Moho with the plate interface. 4.) A deep group of intermediate depth events between 80 to 120 km depth are present north of 36°S. 5.) The magmatic arc exhibits a small amount of crustal seismicity but does not appear to show significantly enhanced activity after the mainshock 6.) Pronounced crustal aftershock activity is found in the region of Pichilemu (~34.5°S). The time-series of postseismic deformation analyzed here show rapid transient deformation immediately following the Maule earthquake. We examine the relation between the spatial-temporal properties of the aftershock

  18. Testing new methodologies for short -term earthquake forecasting: Multi-parameters precursors

    NASA Astrophysics Data System (ADS)

    Ouzounov, Dimitar; Pulinets, Sergey; Tramutoli, Valerio; Lee, Lou; Liu, Tiger; Hattori, Katsumi; Kafatos, Menas

    2014-05-01

    We are conducting real-time tests involving multi-parameter observations over different seismo-tectonics regions in our investigation of phenomena preceding major earthquakes. Our approach is based on a systematic analysis of several selected parameters, namely: gas discharge; thermal infrared radiation; ionospheric electron density; and atmospheric temperature and humidity, which we believe are all associated with the earthquake preparation phase. We are testing a methodology capable to produce alerts in advance of major earthquakes (M > 5.5) in different regions of active earthquakes and volcanoes. During 2012-2013 we established a collaborative framework with PRE-EARTHQUAKE (EU) and iSTEP3 (Taiwan) projects for coordinated measurements and prospective validation over seven testing regions: Southern California (USA), Eastern Honshu (Japan), Italy, Greece, Turkey, Taiwan (ROC), Kamchatka and Sakhalin (Russia). The current experiment provided a "stress test" opportunity to validate the physical based earthquake precursor approach over regions of high seismicity. Our initial results are: (1) Real-time tests have shown the presence of anomalies in the atmosphere and ionosphere before most of the significant (M>5.5) earthquakes; (2) False positives exist and ratios are different for each region, varying between 50% for (Southern Italy), 35% (California) down to 25% (Taiwan, Kamchatka and Japan) with a significant reduction of false positives as soon as at least two geophysical parameters are contemporarily used; (3) Main problems remain related to the systematic collection and real-time integration of pre-earthquake observations. Our findings suggest that real-time testing of physically based pre-earthquake signals provides a short-term predictive power (in all three important parameters, namely location, time and magnitude) for the occurrence of major earthquakes in the tested regions and this result encourages testing to continue with a more detailed analysis of

  19. Strong earthquakes, novae and cosmic ray environment

    NASA Technical Reports Server (NTRS)

    Yu, Z. D.

    1985-01-01

    Observations about the relationship between seismic activity and astronomical phenomena are discussed. First, after investigating the seismic data (magnitude 7.0 and over) with the method of superposed epochs it is found that world seismicity evidently increased after the occurring of novae with apparent magnitude brighter than 2.2. Second, a great many earthquakes of magnitude 7.0 and over occurred in the 13th month after two of the largest ground level solar cosmic ray events (GLEs). The causes of three high level phenomena of global seismic activity in 1918-1965 can be related to these, and it is suggested that according to the information of large GLE or bright nova predictions of the times of global intense seismic activity can be made.

  20. Earthquakes on Your Dinner Table

    NASA Astrophysics Data System (ADS)

    Alexeev, N. A.; Tape, C.; Alexeev, V. A.

    2016-12-01

    Earthquakes have interesting physics applicable to other phenomena like propagation of waves, also, they affect human lives. This study focused on three questions, how: depth, distance from epicenter and ground hardness affect earthquake strength. Experimental setup consisted of a gelatin slab to simulate crust. The slab was hit with a weight and earthquake amplitude was measured. It was found that earthquake amplitude was larger when the epicenter was deeper, which contradicts observations and probably was an artifact of the design. Earthquake strength was inversely proportional to the distance from the epicenter, which generally follows reality. Soft and medium jello were implanted into hard jello. It was found that earthquakes are stronger in softer jello, which was a result of resonant amplification in soft ground. Similar results are found in Minto Flats, where earthquakes are stronger and last longer than in the nearby hills. Earthquakes waveforms from Minto Flats showed that that the oscillations there have longer periods compared to the nearby hills with harder soil. Two gelatin pieces with identical shapes and different hardness were vibrated on a platform at varying frequencies in order to demonstrate that their resonant frequencies are statistically different. This phenomenon also occurs in Yukon Flats.

  1. ERTS-1 image contributes to understanding of geologic structures related to Managua earthquake, 1972

    NASA Technical Reports Server (NTRS)

    Carter, W. D.; Eaton, G. P.

    1973-01-01

    ERTS-1 imaged the western portion of Nicaragua on December 24, 1972, one day after the central part of the city of Managua was devastated by a major earthquake which measured 5.6 on the Richter scale. ERTS-1 images reveal sets of lineaments (which may reflect fault systems) along any one of which movement could have taken place. One set includes a line of active volcanoes that parallels the coast and constitutes the southwestern edge of the Nicaraguan Depression, a regional graben which cuts obliquely across the Central American isthmus. This trend is offset approximately 10km in a right lateral geometric sense just west of the city of Managua. A parallel lineament, north of Lake Managua, marks the northeast edge of the graben. A second set, extends northward to northwestward from the mouth of the Rio Grande (Viejo) north of Lake Managua and can be projected southward across the lake to Managua. It is this set along which geometric offset of the volcanic lineament appears to have taken place.

  2. Anomalous chemical changes in well waters and possible relation to earthquakes.

    Chi-Yu, King; Evans, William C.; Presser, T.; Husk, R.H.

    1981-01-01

    Water level, temperature, salinity, electric conductivity, and pH have been measured periodically for several years at three water wells located along a 17km segment of the San Andreas fault between San Juan Bautista and Cienega Winery in central California. Water samples were collected at the same time for subsequent chemical analyses in the laboratory. Some sudden large changes in salinity and conductivity were recorded in early March 1980 at the two wells near San Juan Bautista. These changes coincided approximately with the beginning of an episode of increased local seismicity, including a magnitude 4.8 earthquake on April 13. Analyses of water samples revealed corresponding changes in ion concentrations, especially of Na+, Ca2+, Mg2+, 035SO42-, 046HCO3-, F-, and Cl-. The observed changes may be the result of mixing of waters from different aquifers through cracks developed in the water barriers by a possible crustal strain episode that may have occurred in the study area.-Authors

  3. A seismological study of shallow weak earthquakes in the urban area of Hamburg city, Germany, and its possible relation to salt dissolution

    NASA Astrophysics Data System (ADS)

    Dahm, Torsten; Heimann, Sebastian; Bialowons, Wilhelm

    2010-05-01

    In the night from 8/9 April 2009, shortly after midnight on Maundy Thursday before Easter, several people in Gross-Flottbek, Hamburg, felt unusual strong ground shocks so that some of them left their houses in fear of earthquake shaking. Police and Fire Brigade received phone calls of worried residents, and few days later Internet pages were published where people reported their observations. On 21 April 2009 at about 8 p.m. local time a second micro-earthquake was felt. Damage to buildings or infrastructure did not occur to our knowledge. The Institute of Geophysics, University of Hamburg, installed from 22 April to 17 May 2009 three temporal seismic stations in the epicentral area. Seismological data from two close-by stations at the Deutsches Elektron-Synchrotron (DESY) in about 1 km and the Geophysical Institute in about 7 km distance were collected and integrated to the temporal network. The events occurred above the roof of the shallow Othmarschen Langenfelde salt diapir (OLD), in an area known for active sinkhole formation and previous historic ground shaking events. The analysis of the seismological data recovers that three shallow micro-earthquakes occurred from 8 to 21 April at a depth of about 100m, the largest one with a moment magnitude of about MW 0.6. Depth location of such shallow events is difficult with standard methods, and is here constrained by waveform modeling of surface waves. Earthquakes occurring in soft sediments within the uppermost 100 m are a rare phenomena and cannot be explained by standard models. Rupture process in soft sediments differ from those on faults in more competent rock. We discuss the rupture and source mechanism of the earthquakes in the context of previous historic shocks and existing sinkhole and deformation data. Although the event was so weak, the rupture duration was unusual long and possibly 0.3 s. Three possible models for the generation of repeated micro-earthquakes in Gross Flottbek are developed and discussed

  4. State-of-the-Art for Assessing Earthquake Hazards in the United States. Report 25. Parameters for Specifying Intensity-Related Earthquake Ground Motions.

    DTIC Science & Technology

    1987-09-01

    and Sponheuer, W. 1969. Scale of Seismic Intensity: Proc. Fourth World Conf. on Earthquake Engineering, Santiago, Chile . Murphy, J. R., and O’Brien, L...Predom V/H el, V/I Vel V/H Displ V/H sec VIH Period Period Predom Accel cm/sec Vel cm Disp .05 Dur sec sec Period S11 2 0.48 MODIFIED MERCALLI INTENSITY...0.1 0. 0.16 142.20 Long. Vert Hor Vert Ratio Ratio Vert Ratio Vert r io Du r atio Predom Predom VIH Acce V/H Vel V /H Dspi V H sec 1, H Period Period

  5. Pre-seismic geomagnetic and ionosphere signatures related to the Mw5.7 earthquake occurred in Vrancea zone on September 24, 2016

    NASA Astrophysics Data System (ADS)

    Stanica, Dragos Armand; Stanica, Dumitru; Błęcki, Jan; Ernst, Tomasz; Jóźwiak, Waldemar; Słomiński, Jan

    2018-02-01

    To emphasize the relationship between the pre-seismic geomagnetic signals and Vrancea seismicity, in this work it is hypothesized that before an earthquake initiation, the high stress reached into seismogenic volume generates dehydration of the rocks and fracturing processes followed by release of electric charges along the faulting systems, which lead to resistivity changes. These changes were explored on September 2016 by the normalized function Bzn obtained from the geomagnetic data recorded in ULF range (0.001-0.0083 Hz). A statistical analysis was also performed to discriminate on the new Bzn* time series a pre-seismic signature related to the Mw5.7 earthquake. Significant anomalous behavior of Bzn* was identified on September 21, with 3 days prior to the onset of the seismic event. Similar information is provided by registrations of the magnetic and electron concentration variations in the ionosphere over the Vrancea zone, by Swarm satellites, 4 days and 1 day before the earthquake.

  6. Relations between Post-traumatic Stress Disorder, Dissociation and Attention-Deficit/Hyperactivity Disorder among Earthquake Survivors

    PubMed Central

    ÖZDEMİR, Osman; BOYSAN, Murat; GÜZEL ÖZDEMİR, Pınar; YILMAZ, Ekrem

    2015-01-01

    Introduction There is a burgeoning interest in relations between post-traumatic stress disorder (PTSD) and attention-deficit/hyperactivity disorder (ADHD). Although few studies were conducted, weak evidence was found supporting the hypothesis that ADHD may be a risk factor for the development of PTSD. In addition, there is a paucity of research addressing the relations between dissociation and ADHD. In this study, our aim was to examine the relations between PTSD and ADHD combined with the mediating effect of dissociative psychopathology. Methods The participants were 317 undergraduate students, a greater proportion of whom experienced the 2011 Van earthquake (66%). The participants were administered the Posttraumatic Diagnostic Scale, Dissociative Experiences Scale, Adult ADHD Self-Report Scale, Beck Depression Inventory and Beck Anxiety Inventory. Results We found that ADHD symptoms and dissociation were significantly associated with PTSD. Considering the multivariate relations between ADHD, PTSD and dissociation, significant associations between PTSD and ADHD resulted from symptom overlaps. However, pathological dissociation mediated the relations between PTSD and ADHD. Conclusion We concluded that ADHD comorbidity was not a predominant vulnerability factor for the development of post-traumatic stress response but may be an exacerbating factor after the development of PTSD. PMID:28360719

  7. Evidence for late Holocene relative sea-level fall from reconnaissance stratigraphical studies in an area of earthquake-subsided intertidal deposits, Isla Chiloé, southern Chile

    Frostick, L.E.; Steel, R.J.; Bartsch-Winkler, S.; Schmoll, H.R.

    1993-01-01

    At Río Pudeto and Quetalmahue, two estuaries along the northern shore of Isla Chiloé that subsided as much as 2 m in the great 1960 earthquake, reconnaissance stratigraphical studies reveal evidence of a regressive, nearshore marine sequence. The intertidal deposits include a peat-bearing, high-intertidal marsh sequence as thick as 1.4 m overlying shell- and foraminifera-bearing silt and clay layers presumed to represent a deeper water, low-intertidal environment.Stratigraphy indicates a relative sea-level fall since about 5000 years BP as evidenced by radiocarbon ages that constrain the peat-bearing sequences. Locally, low-intertidal silt and clay overlie high-intertidal peat layers, but such minor transgressions cannot be correlated from site to site. At Río Pudeto, the youngest foraminifera-bearing silt deposit is no younger than 1200 years BP. The youngest age of shells at Quetalmahue is about 2600 years BP. The oldest peat-bearing deposits that are not overlain by silt deposits are about 1350 years BP at Río Pudeto, and as old as 4900 years BP at Quetalmahue. At Río Pudeto, peat-bearing deposits, which are overlain by silt and clay, range in age from 760 to 5430 years BP, and at Quetalmahue from 290 to 5290 years BP. A beach terrace on the northwest coast of the Isla is estimated to have been emergent since 1150 + 130 years ago.Although some relatively abrupt transgressions may be due to sudden coseismic subsidence, data are not sufficient to document regional subsidence during individual plate-interface earthquakes. Seven earthquakes in south central Chile since 1520, especially those that occurred in 1575, 1737, and 1837, are thought to have been of a magnitude comparable to that of the 1960 earthquake. Although the sedimentological effects of the 1960 earthquake on the intertidal zone were dramatic, only limited evidence of possible historic earthquakes is found on Isla Chiloé and nearby islands; the ages and displacements of these earthquakes are

  8. Nursing phenomena in inpatient psychiatry.

    PubMed

    Frauenfelder, F; Müller-Staub, M; Needham, I; Van Achterberg, T

    2011-04-01

    Little is known about the question if the nursing diagnosis classification of North American Nursing Association-International (NANDA-I) describes the adult inpatient psychiatric nursing care. The present study aimed to identify nursing phenomena mentioned in journal articles about the psychiatric inpatient nursing care and to compare these phenomena with the labels and the definitions of the nursing diagnoses to elucidate how well this classification covers these phenomena. A search of journal articles took place in the databases MedLine, PsychInfo, Cochrane and CINAHL. A qualitative content analysis approach was used to identify nursing phenomena in the articles. Various phenomena were found in the articles. The study demonstrated that NANDA-I describes essential phenomena for the adult inpatient psychiatry on the level of labels and definitions. However, some apparently important nursing phenomena are not covered by the labels or definitions of NANDA-I. Other phenomena are assigned as defining characteristics or as related factors to construct nursing diagnoses. The further development of the classification NANDA-I will strengthen the application in the daily work of psychiatric nurses and enhance the quality of nursing care in the inpatient setting. © 2010 Blackwell Publishing.

  9. Crustal deformation at the terminal stage before earthquake occurrence

    NASA Astrophysics Data System (ADS)

    Chen, C. H.; Meng, G.; Su, X.

    2016-12-01

    GPS data retrieved from 300 stations in China are used in this work to study stressed areas during earthquake preparation periods. Surface deformation data are derived by using the standard method and are smoothed by a temporal moving to mitigate influence from noise. A statistical method is used to distinguish significant variations from the smoothed data. The spatial distributions comprised of those significant variations show that a diameter of a stressed area preparing earthquakes is about 3500 km for a M6 event. The deformation deduced from the significant variations is highly related with the slip direction of the fault plane determined through the focal mechanism solution of earthquakes. Although the causal mechanism of such large stressed areas with rapid changes is not fully understood, the analytical results suggest that the earthquake preparation would be one of the factors dominating the common mode error in GPS studies. Mechanisms and/or numerical models of some pre-earthquake anomalous phenomena would be reconsidered based on this novel observation.

  10. What Can Sounds Tell Us About Earthquake Interactions?

    NASA Astrophysics Data System (ADS)

    Aiken, C.; Peng, Z.

    2012-12-01

    It is important not only for seismologists but also for educators to effectively convey information about earthquakes and the influences earthquakes can have on each other. Recent studies using auditory display [e.g. Kilb et al., 2012; Peng et al. 2012] have depicted catastrophic earthquakes and the effects large earthquakes can have on other parts of the world. Auditory display of earthquakes, which combines static images with time-compressed sound of recorded seismic data, is a new approach to disseminating information to a general audience about earthquakes and earthquake interactions. Earthquake interactions are influential to understanding the underlying physics of earthquakes and other seismic phenomena such as tremors in addition to their source characteristics (e.g. frequency contents, amplitudes). Earthquake interactions can include, for example, a large, shallow earthquake followed by increased seismicity around the mainshock rupture (i.e. aftershocks) or even a large earthquake triggering earthquakes or tremors several hundreds to thousands of kilometers away [Hill and Prejean, 2007; Peng and Gomberg, 2010]. We use standard tools like MATLAB, QuickTime Pro, and Python to produce animations that illustrate earthquake interactions. Our efforts are focused on producing animations that depict cross-section (side) views of tremors triggered along the San Andreas Fault by distant earthquakes, as well as map (bird's eye) views of mainshock-aftershock sequences such as the 2011/08/23 Mw5.8 Virginia earthquake sequence. These examples of earthquake interactions include sonifying earthquake and tremor catalogs as musical notes (e.g. piano keys) as well as audifying seismic data using time-compression. Our overall goal is to use auditory display to invigorate a general interest in earthquake seismology that leads to the understanding of how earthquakes occur, how earthquakes influence one another as well as tremors, and what the musical properties of these

  11. Fractal dynamics of earthquakes

    SciT

    Bak, P.; Chen, K.

    1995-05-01

    Many objects in nature, from mountain landscapes to electrical breakdown and turbulence, have a self-similar fractal spatial structure. It seems obvious that to understand the origin of self-similar structures, one must understand the nature of the dynamical processes that created them: temporal and spatial properties must necessarily be completely interwoven. This is particularly true for earthquakes, which have a variety of fractal aspects. The distribution of energy released during earthquakes is given by the Gutenberg-Richter power law. The distribution of epicenters appears to be fractal with dimension D {approx} 1--1.3. The number of after shocks decay as a function ofmore » time according to the Omori power law. There have been several attempts to explain the Gutenberg-Richter law by starting from a fractal distribution of faults or stresses. But this is a hen-and-egg approach: to explain the Gutenberg-Richter law, one assumes the existence of another power-law--the fractal distribution. The authors present results of a simple stick slip model of earthquakes, which evolves to a self-organized critical state. Emphasis is on demonstrating that empirical power laws for earthquakes indicate that the Earth`s crust is at the critical state, with no typical time, space, or energy scale. Of course the model is tremendously oversimplified; however in analogy with equilibrium phenomena they do not expect criticality to depend on details of the model (universality).« less

  12. DSM-5 posttraumatic stress symptom dimensions and health-related quality of life among Chinese earthquake survivors.

    PubMed

    Li, Gen; Wang, Li; Cao, Chengqi; Fang, Ruojiao; Liu, Ping; Luo, Shu; Zhang, Jianxin; Hall, Brain J; Elhai, Jon D

    2018-01-01

    It has been well-documented that posttraumatic stress symptoms cause impairments in health-related quality of life (HRQoL). Until now we have little data on how DSM-5 PTSD symptom dimensions relate to different aspects of HRQoL. Clarifying this question would be informative to improve the quality of life of PTSD patients. This study aimed to investigate the effects of dimensions of a well-supported seven-factor model of DSM-5 PTSD symptoms on physical and psychosocial HRQoL. A total of 1063 adult survivors of the 2008 Wenchuan earthquake took part in this study nine years after the disaster. PTSD symptoms were measured by the PTSD Checklist for DSM-5 (PCL-5). HRQoL was measured by the Medical Outcomes Survey Short Form-36 (SF-36). The associations between PTSD symptom dimensions and HRQoL were examined using structural equation models. Dysphoric arousal symptoms were found to significantly relate to physical HRQoL. Other symptom dimensions were not associated with HRQoL. Our findings contribute to the relationship between DSM-5 PTSD and HRQoL, and carry implications for further clinical practice and research on trauma-exposed individuals.

  13. DSM-5 posttraumatic stress symptom dimensions and health-related quality of life among Chinese earthquake survivors

    PubMed Central

    Cao, Chengqi; Fang, Ruojiao; Liu, Ping; Luo, Shu; Zhang, Jianxin; Hall, Brain J.; Elhai, Jon D.

    2018-01-01

    ABSTRACT It has been well-documented that posttraumatic stress symptoms cause impairments in health-related quality of life (HRQoL). Until now we have little data on how DSM-5 PTSD symptom dimensions relate to different aspects of HRQoL. Clarifying this question would be informative to improve the quality of life of PTSD patients. This study aimed to investigate the effects of dimensions of a well-supported seven-factor model of DSM-5 PTSD symptoms on physical and psychosocial HRQoL. A total of 1063 adult survivors of the 2008 Wenchuan earthquake took part in this study nine years after the disaster. PTSD symptoms were measured by the PTSD Checklist for DSM-5 (PCL-5). HRQoL was measured by the Medical Outcomes Survey Short Form-36 (SF-36). The associations between PTSD symptom dimensions and HRQoL were examined using structural equation models. Dysphoric arousal symptoms were found to significantly relate to physical HRQoL. Other symptom dimensions were not associated with HRQoL. Our findings contribute to the relationship between DSM-5 PTSD and HRQoL, and carry implications for further clinical practice and research on trauma-exposed individuals. PMID:29736219

  14. A new asymptotic method for jump phenomena

    NASA Technical Reports Server (NTRS)

    Reiss, E. L.

    1980-01-01

    Physical phenomena involving rapid and sudden transitions, such as snap buckling of elastic shells, explosions, and earthquakes, are characterized mathematically as a small disturbance causing a large-amplitude response. Because of this, standard asymptotic and perturbation methods are ill-suited to these problems. In the present paper, a new method of analyzing jump phenomena is proposed. The principal feature of the method is the representation of the response in terms of rational functions. For illustration, the method is applied to the snap buckling of an elastic arch and to a simple combustion problem.

  15. Development of a national system for prevention and mitigation of earthquake damages to people and properties, and the reduction of costs related to earthquakes for the Italian Government

    NASA Astrophysics Data System (ADS)

    Console, R.; Greco, M.; Colangelo, A.; Cioè, A.; Trivigno, L.; Chiappini, M.; Ponzo, F.

    2015-12-01

    Recognizing that the Italian territory is prone to disasters in connection with seismic and hydro-geological risk, it has become necessary to define novel regulations and viable solutions aimed at conveying the economical resources of the Italian Government, too often utilized for the management of post-event situations, towards prevention activities. The work synthetically presents the project developed by the CGIAM together with the INGV, and open to collaboration with other Italian and International partners. This project is aimed at the development of a National System for prevention and mitigation of the earthquakes damages, through the definition of a model that achieves the mitigation of the building collapsing risk and the consequent reduction of casualties. Such a model is based on two main issues a) a correct evaluation of risk, defined as a reliable assessment of the hazard expected at a given site and of the vulnerability of civil and industrial buildings, b) setting up of novel strategies for the safety of buildings. The hazard assessment is pursued through the application of innovative multidisciplinary geophysical methodologies and the application of a physically based earthquake simulator. The structural vulnerability of buildings is estimated by means of simplified techniques based on few representative parameters (such as different structural typologies, dynamic soil-structure interaction, etc.) and, for detailed studies, standard protocols for model updating techniques. We analyze, through numerical and experimental approaches, new solutions for the use of innovative materials, and new techniques for the reduction of seismic vulnerability of structural, non-structural and accessorial elements, including low cost type. The project activities are initially implemented on a study area in Southern Italy (Calabria) selected because of its tectonic complexity. The results are expected to be applicable for other hazardous seismic areas of Italy.

  16. Relative locations between shallow very low frequency earthquakes and low frequency tremors investigated based on near-filed BBOBS records

    NASA Astrophysics Data System (ADS)

    Chi, W. C.; To, A.; Chen, W. J.; Konishi, K.

    2017-12-01

    Two types of anomalous seismic events of long duration with signals depleted in high frequencies relative to most earthquakes are recorded in a network of broadband ocean bottom seismometers (BBOBS) deployed at shallow Nankai subduction zone (DONET1). The first type is very low frequency earthquake (VLFE) whose signals are observed both in the lower and higher frequency ranges of the 0.1 Hz microseism band, which are 0.02-0.06 Hz and 2-8 Hz. The second type is low frequency tremor (LFT), whose signals are only observed at 2-8 Hz. The waveform similarity at 2-8 Hz and concurrences of the two types of event warrant further investigations on whether they represent the same phenomenon or not. Previously, To et al., (2015) examined the relation between VLFEs and LFTs by comparing their maximum amplitude at two different frequency ranges, 2-8 Hz and 0.02-0.05 Hz. The comparison showed that the maximum amplitudes measured at the two frequency ranges correlate positively for VLFEs, that is, large magnitude VLFEs showed large amplitude in both frequency ranges. The comparison also showed that the amplitude measured at 2-8 Hz were larger for VLFEs than those of LFTs. Based on such amplitude observations, they concluded that VLFEs and LFTs are likely smaller and larger events of the same phenomenon. Here, we examined the relation between the two types of event based on their spatial distribution. Their distributions should be similar if they represent the same phenomenon. The data are broadband seismographs of 20 stations of DONET1. We detected 144 VLFEs and 775 LFTs during the intense LFT/VLFE activity period of one week in October 2015. Events are located using an envelope cross correlation method. We used the root-mean-square (RMS) amplitudes constructed from the two horizontal components, bandpass filtered at 2-­8 Hz and then smoothed by taking a moving average with a window length of 5 s. The obtained distributions of VLFEs and LFTs show similar patterns. They both

  17. Recurrence and interoccurrence behavior of self-organized complex phenomena

    NASA Astrophysics Data System (ADS)

    Abaimov, S. G.; Turcotte, D. L.; Shcherbakov, R.; Rundle, J. B.

    2007-08-01

    The sandpile, forest-fire and slider-block models are said to exhibit self-organized criticality. Associated natural phenomena include landslides, wildfires, and earthquakes. In all cases the frequency-size distributions are well approximated by power laws (fractals). Another important aspect of both the models and natural phenomena is the statistics of interval times. These statistics are particularly important for earthquakes. For earthquakes it is important to make a distinction between interoccurrence and recurrence times. Interoccurrence times are the interval times between earthquakes on all faults in a region whereas recurrence times are interval times between earthquakes on a single fault or fault segment. In many, but not all cases, interoccurrence time statistics are exponential (Poissonian) and the events occur randomly. However, the distribution of recurrence times are often Weibull to a good approximation. In this paper we study the interval statistics of slip events using a slider-block model. The behavior of this model is sensitive to the stiffness α of the system, α=kC/kL where kC is the spring constant of the connector springs and kL is the spring constant of the loader plate springs. For a soft system (small α) there are no system-wide events and interoccurrence time statistics of the larger events are Poissonian. For a stiff system (large α), system-wide events dominate the energy dissipation and the statistics of the recurrence times between these system-wide events satisfy the Weibull distribution to a good approximation. We argue that this applicability of the Weibull distribution is due to the power-law (scale invariant) behavior of the hazard function, i.e. the probability that the next event will occur at a time t0 after the last event has a power-law dependence on t0. The Weibull distribution is the only distribution that has a scale invariant hazard function. We further show that the onset of system-wide events is a well defined

  18. Earthquake Hazards.

    ERIC Educational Resources Information Center

    Donovan, Neville

    1979-01-01

    Provides a survey and a review of earthquake activity and global tectonics from the advancement of the theory of continental drift to the present. Topics include: an identification of the major seismic regions of the earth, seismic measurement techniques, seismic design criteria for buildings, and the prediction of earthquakes. (BT)

  19. Real-Time Earthquake Monitoring with Spatio-Temporal Fields

    NASA Astrophysics Data System (ADS)

    Whittier, J. C.; Nittel, S.; Subasinghe, I.

    2017-10-01

    With live streaming sensors and sensor networks, increasingly large numbers of individual sensors are deployed in physical space. Sensor data streams are a fundamentally novel mechanism to deliver observations to information systems. They enable us to represent spatio-temporal continuous phenomena such as radiation accidents, toxic plumes, or earthquakes almost as instantaneously as they happen in the real world. Sensor data streams discretely sample an earthquake, while the earthquake is continuous over space and time. Programmers attempting to integrate many streams to analyze earthquake activity and scope need to write code to integrate potentially very large sets of asynchronously sampled, concurrent streams in tedious application code. In previous work, we proposed the field stream data model (Liang et al., 2016) for data stream engines. Abstracting the stream of an individual sensor as a temporal field, the field represents the Earth's movement at the sensor position as continuous. This simplifies analysis across many sensors significantly. In this paper, we undertake a feasibility study of using the field stream model and the open source Data Stream Engine (DSE) Apache Spark(Apache Spark, 2017) to implement a real-time earthquake event detection with a subset of the 250 GPS sensor data streams of the Southern California Integrated GPS Network (SCIGN). The field-based real-time stream queries compute maximum displacement values over the latest query window of each stream, and related spatially neighboring streams to identify earthquake events and their extent. Further, we correlated the detected events with an USGS earthquake event feed. The query results are visualized in real-time.

  20. Progress in Understanding the Pre-Earthquake Associated Events by Analyzing IR Satellite Data

    NASA Technical Reports Server (NTRS)

    Ouzounov, Dimitar; Taylor, Patrick; Bryant, Nevin

    2004-01-01

    We present latest result in understanding the potential relationship between tectonic stress, electro-chemical and thermodynamic processes in the Earths crust and atmosphere with an increase in IR flux as a potential signature of electromagnetic (EM) phenomena that are related to earthquake activity, either pre-, co- or post seismic. Thermal infra-red (TIR) surveys performed by the polar orbiting (NOAA/AVHRR MODIS) and geosynchronous weather satellites (GOES, METEOSAT) gave an indication of the appearance (from days to weeks before the event) of "anomalous" space-time TIR transients that are associated with the location (epicenter and local tectonic structures) and time of a number of major earthquakes with M>5 and focal depths less than 50km. We analyzed broad category of associated pre-earthquake events, which provided evidence for changes in surface temperature, surface latent heat flux, chlorophyll concentrations, soil moisture, brightness temperature, emissivity of surface, water vapour in the atmosphere prior to the earthquakes occurred in Algeria, India, Iran, Italy, Mexico and Japan. The cause of such anomalies has been mainly related to the change of near-surface thermal properties due to complex lithosphere-hydrosphere-atmospheric interactions. As final results we present examples from the most recent (2000-2004) worldwide strong earthquakes and the techniques used to capture the tracks of EM emission mid-IR anomalies and a methodology for practical future use of such phenomena in the early warning systems.

  1. Report on the Aseismic Slip, Tremor, and Earthquakes Workshop

    Gomberg, Joan; Roeloffs, Evelyn; Trehu, Anne; Dragert, Herb; Meertens, Charles

    2008-01-01

    This report summarizes the discussions and information presented during the workshop on Aseismic Slip, Tremor, and Earthquakes. Workshop goals included improving coordination among those involved in conducting research related to these phenomena, assessing the implications for earthquake hazard assessment, and identifying ways to capitalize on the education and outreach opportunities presented by these phenomena. Research activities of focus included making, disseminating, and analyzing relevant measurements; the relationships among tremor, aseismic or 'slow-slip', and earthquakes; and discovering the underlying causative physical processes. More than 52 participants contributed to the workshop, held February 25-28, 2008 in Sidney, British Columbia. The workshop was sponsored by the U.S. Geological Survey, the National Science Foundation?s Earthscope Program and UNAVCO Consortium, and the Geological Survey of Canada. This report has five parts. In the first part, we integrate the information exchanged at the workshop as it relates to advancing our understanding of earthquake generation and hazard. In the second part, we summarize the ideas and concerns discussed in workshop working groups on Opportunities for Education and Outreach, Data and Instrumentation, User and Public Needs, and Research Coordination. The third part presents summaries of the oral presentations. The oral presentations are grouped as they were at the workshop in the categories of phenomenology, underlying physical processes, and implications for earthquake hazards. The fourth part contains the meeting program and the fifth part lists the workshop participants. References noted in parentheses refer to the authors of presentations made at the workshop, and published references are noted in square brackets and listed in the Reference section. Appendix A contains abstracts of all participant presentations and posters, which also have been posted online, along with presentations and author contact

  2. The relation of cool flames and auto-ignition phenomena to process safety at elevated pressure and temperature.

    PubMed

    Pekalski, A A; Zevenbergen, J F; Pasman, H J; Lemkowitz, S M; Dahoe, A E; Scarlett, B

    2002-07-01

    The cool-flame phenomenon can occur in fuel-oxygen (air) mixtures within the flammable range and outside the flammable range, at fuel-rich compositions, at temperatures below the auto-ignition temperature (AIT). It is caused by chemical reactions occurring spontaneously at relatively low temperatures and is favoured by elevated pressure. The hazards that cool flames generate are described. These vary from spoiling a product specification through contamination and explosive decomposition of condensed peroxides to the appearance of unexpected normal (hot) flame (two-stage ignition).

  3. OMG Earthquake! Can Twitter improve earthquake response?

    NASA Astrophysics Data System (ADS)

    Earle, P. S.; Guy, M.; Ostrum, C.; Horvath, S.; Buckmaster, R. A.

    2009-12-01

    The U.S. Geological Survey (USGS) is investigating how the social networking site Twitter, a popular service for sending and receiving short, public, text messages, can augment its earthquake response products and the delivery of hazard information. The goal is to gather near real-time, earthquake-related messages (tweets) and provide geo-located earthquake detections and rough maps of the corresponding felt areas. Twitter and other social Internet technologies are providing the general public with anecdotal earthquake hazard information before scientific information has been published from authoritative sources. People local to an event often publish information within seconds via these technologies. In contrast, depending on the location of the earthquake, scientific alerts take between 2 to 20 minutes. Examining the tweets following the March 30, 2009, M4.3 Morgan Hill earthquake shows it is possible (in some cases) to rapidly detect and map the felt area of an earthquake using Twitter responses. Within a minute of the earthquake, the frequency of “earthquake” tweets rose above the background level of less than 1 per hour to about 150 per minute. Using the tweets submitted in the first minute, a rough map of the felt area can be obtained by plotting the tweet locations. Mapping the tweets from the first six minutes shows observations extending from Monterey to Sacramento, similar to the perceived shaking region mapped by the USGS “Did You Feel It” system. The tweets submitted after the earthquake also provided (very) short first-impression narratives from people who experienced the shaking. Accurately assessing the potential and robustness of a Twitter-based system is difficult because only tweets spanning the previous seven days can be searched, making a historical study impossible. We have, however, been archiving tweets for several months, and it is clear that significant limitations do exist. The main drawback is the lack of quantitative information

  4. Complex surface rupturing and related formation mechanisms in the Xiaoyudong area for the 2008 Mw 7.9 Wenchuan Earthquake, China

    NASA Astrophysics Data System (ADS)

    Tan, Xi-bin; Yuan, Ren-mao; Xu, Xi-wei; Chen, Gui-hua; Klinger, Yann; Chang, Chung-Pai; Ren, Jun-jie; Xu, Chong; Li, Kang

    2012-09-01

    The large oblique reverse slip shock of the 2008 Mw = 7.9 Wenchuan earthquake, China, produced one of the longest and most complicated surface ruptures ever known. The complexity is particularly evident in the Xiaoyudong area, where three special phenomena occurred: the 7 km long Xiaoyudong rupture perpendicular to the Beichuan-Yingxiu fault; the occurrence of two parallel faults rupturing simultaneously, and apparent discontinuity of the Beichuan-Yingxiu rupture. This paper systematically documents these co-seismic rupture phenomena for the Xiaoyudong area. The discussion and results are based on field investigations and analyses of faulting mechanisms and prevalent stress conditions. The results show that the Beichuan-Yingxiu fault formed a 3.5 km wide restraining stepover at the Xiaoyudong area. The Xiaoyudong fault is not a tear fault suggested by previous researches, but a frontal reverse fault induced by the oblique compression at this stepover; it well accommodates the 'deformation gap' of the Beichuan-Yingxiu fault in the Xiaoyudong area. Further, stress along the Peng-Guan fault plane doubles due to a change in dip angle of the Beichuan-Yingxiu fault across the Xiaoyudong restraining stepover. This resulted in two faults rupturing the ground's surface simultaneously, to the north of the Xiaoyudong area. These results are helpful in deepening our understanding of the dynamic processes that produced surface ruptures during the Wenchuan earthquake. Furthermore, the results suggest more attention be focused on the influence of dextral slip component, the change of the control fault's attitude, and property differences in rocks on either side of faults when discussing the formation mechanism of surface ruptures.

  5. Earthquakes, November-December 1991

    Person, W.J.

    1992-01-01

    There were three major earthquakes (7.0-7.9) during the last two months of the year: a magntidue 7.0 on November 19 in Columbia, a magnitude 7.4 in the Kuril Islands on December 22, and a magnitude 7.1 in the South Sandwich Islands on December 27. Earthquake-related deaths were reported in Colombia, Yemen, and Iran. there were no significant earthquakes in the United States during this reporting period. 

  6. Investigation of Ionospheric Anomalies related to moderate Romanian earthquakes occurred during last decade using VLF/LF INFREP and GNSS Global Networks

    NASA Astrophysics Data System (ADS)

    Moldovan, Iren-Adelina; Oikonomou, Christina; Haralambous, Haris; Nastase, Eduard; Emilian Toader, Victorin; Biagi, Pier Francesco; Colella, Roberto; Toma-Danila, Dragos

    2017-04-01

    Ionospheric TEC (Total Electron Content) variations and Low Frequency (LF) signal amplitude data prior to five moderate earthquakes (Mw≥5) occurred in Romania, in Vrancea crustal and subcrustal seismic zones, during the last decade were analyzed using observations from the Global Navigation Satellite System (GNSS) and the European INFREP (International Network for Frontier Research on Earthquake Precursors) networks respectively, aiming to detect potential ionospheric anomalies related to these events and describe their characteristics. For this, spectral analysis on TEC data and terminator time method on VLF/LF data were applied. It was found that TEC perturbations appeared few days (1-7) up to few hours before the events lasting around 2-3 hours, with periods 20 and 3-5 minutes which could be associated with the impending earthquakes. In addition, in all three events the sunrise terminator times were delayed approximately 20-40 min few days prior and during the earthquake day. Acknowledgments This work was partially supported by the Partnership in Priority Areas Program - PNII, under MEN-UEFISCDI, DARING Project no. 69/2014 and the Nucleu Program - PN 16-35, Project no. 03 01

  7. Anomalous Diffuse CO2 Emission Changes at San Vicente Volcano Related to Earthquakes in El Salvador, Central America

    NASA Astrophysics Data System (ADS)

    Salazar, J.; Hernandez, P.; Perez, N.; Barahona, F.; Olmos, R.; Cartagena, R.; Soriano, T.; Notsu, K.; Lopez, D.

    2001-12-01

    San Vicente or Chichontepeque (2,180 m a.s.l.) is a composite andesitic volcano located 50 Km east of San Salvador. Its paired edifice rises from the so-called Central Graben, an extensional structure parallel to the Pacific coast, and has been inactive for the last 3000 yrs. Fumaroles (98.2°C ) and hot spring waters are present along radial faults at two localities on the northern slope of the volcano (Aguas Agrias and El Infiernillo). CO2 is the most abundant component in the dry gas (>90%) and its mean isotopic composition (δ 13C(CO2)=-2.11 ‰ and 3He/4He of 6.9 Ra) suggests a magmatic origin for the CO2. These manifestations are supposed to be linked to a 1,200 m depth 250°C reservoir with a CO2 partial pressure of 14 bar extended beneath the volcano (Aiuppa et al., 1997). In February 13, 2001, a 6.6 magnitude earthquake with epicenter about 20 Km W of San Vicente damaged and destroyed many towns and villages in the north area of the volcano causing some deceases. In addition, two seismic swarms were recorded beneath the northeastern flank of the volcano in April and May 2001. Searching for any link between the actual seismic activity and changes in the diffuse CO2 degassing at San Vicente, an NDIR instrument for continuos monitoring of the diffuse CO2 degassing was set up at Aguas Agrias in March 2001. Soil CO2 efflux and several meteorological and soil physical variables were measured in an hourly basis. Very significative pre-seismic and post-seismic relationships have been found in the observed diffuse CO2 efflux temporal variations related to the May 2001 seismic swarms. A sustained 50% increase on the average diffuse CO2 efflux was observed 8 days before the May 8, 5.1 magnitude earthquake. This pre-seismic behaviour may be considered a precursor of the May 2001 seismic swarm at San Vicente volcano. However, about a three-fold increase in the diffuse CO2 efflux was also observed after the intense seismicity recorded on May 8-9. These preliminary

  8. Lichenometry dating of rock collapse related to the great Lisbon Earthquake (1755) at the SE part of Spain

    NASA Astrophysics Data System (ADS)

    Perez-Lopez, Raul; Rodriguez-Pascua, Miguel Angel; Silva, Pablo G.; Bischoff, James L.; Owen, Lewis A.; Giner-Robles, Jorge L.; Díez-Herrero, Andres

    2010-05-01

    "De una montaña, se desprendió una parte" (A large part of a mountain has fallen down). This sentence was extracted from an ancient text written at the end of the 18th Century, in relation with the great Earthquake of Lisbon in 1755 (Martínez-Solares, 2001), and describing the rock collapse recorded near the small town of Agramón, 50 km southeastward of Albacete city (SE of Spain). Up to now, archaeologists have suggested this rock collapse to the archaeological site of "El Tolmo de Minateda", a small butte (420 m long) of calcarenitic sandstone bedrock with a flat top and scarped cliffs (20m high) bordering the butte. This ancient city was habited by several civilizations from Bronze Ages to modern times (i.e. Iberians, Roman, Visigoths, Muslims, Medieval ages, etc.). The landscape of this area is characterized by a flat terrain with isolated relict structural buttes consisting of Late Neogene marine sandstones created by differential erosion. The site exhibits three different stages of massive rock collapse. The oldest is located at the north of the site while the younger is located at the south part of the site and affecting Visigothic stone carved tombs. Archaeologists have postulated that the youngest of these was triggered by the Lisbon earthquake of 1755. We have carried out a lichenometric analysis over the free-faces of the rock blocks, with the aim of testing the postulate. For our purpose, we have calculated the calibrated growth curve for Aspicilia Radiosa (Hoff.), which yields a linear growth of 0.2425 mm per yr (R2 = 0.97, N=20). This growth rate was determined for the time interval from 800 BP yrs to the present by two different approaches: (1) rates obtained from cemetery measurements (200 yrs BP) and (2) rates determined from well-dated archaeological monuments (200-800 yrs BP). Our analysis revealed that the age of the rock-falling was in the year 1754 AD ±4. Thus, our results confirm that this collapse of ca. 5000 m3 of volume was triggered

  9. Stress-related phenomena and detoxification mechanisms induced by common pharmaceuticals in alfalfa (Medicago sativa L.) plants.

    PubMed

    Christou, Anastasis; Antoniou, Chrystalla; Christodoulou, Charalampia; Hapeshi, Evroula; Stavrou, Ioannis; Michael, Costas; Fatta-Kassinos, Despo; Fotopoulos, Vasileios

    2016-07-01

    Pharmaceutically active compounds (PhACs) have been recently shown to exert phytotoxic effects. The present study explores the uptake, systemic translocation, and abiotic stress responses and detoxification mechanisms induced by the exposure of alfalfa plants grown in sand under greenhouse conditions to four common, individually applied PhACs (10μgL(-1)) (diclofenac, sulfamethoxazole, trimethoprim, 17a-ethinylestradiol) and their mixture. Stress physiology markers (lipid peroxidation, proline, H2O2 and NO content, antioxidant activity assays) and gene expression levels of key plant detoxification components (including glutathione S-transferases, GST7, GST17; superoxide dismutases, CuZnSOD, FeSOD; proton pump, H(+)-ATP, and cytochrome c oxidase, CytcOx), were evaluated. PhACs were detected in significantly higher concentrations in roots compared with leaves. Stress related effects, manifested via membrane lipid peroxidation and oxidative burst, were local (roots) rather than systemic (leaves), and exacerbated when the tested PhACs were applied in mixture. Systemic accumulation of H2O2 in leaves suggests its involvement in signal transduction and detoxification responses. Increased antioxidant enzymatic activities, as well as upregulated transcript levels of GST7, GST17, H(+)-ATPase and CytcOx, propose their role in the detoxification of the selected PhACs in plants. The current findings provide novel biochemical and molecular evidence highlighting the studied PhACs as an emerging abiotic stress factor, and point the need for further research on wastewater flows under natural agricultural environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. The October 12, 1992, Dahshur, Egypt, Earthquake

    Thenhaus, P.C.; Celebi, M.; Sharp, R.V.

    1993-01-01

    We were part of an international reconnaissance team that investigated the Dahsur earthquake. This article summarizes our findings and points out how even a relatively moderate sized earthquake can cause widespread damage and a large number of casualities. 

  11. Turkish Compulsory Earthquake Insurance (TCIP)

    NASA Astrophysics Data System (ADS)

    Erdik, M.; Durukal, E.; Sesetyan, K.

    2009-04-01

    Through a World Bank project a government-sponsored Turkish Catastrophic Insurance Pool (TCIP) is created in 2000 with the essential aim of transferring the government's financial burden of replacing earthquake-damaged housing to international reinsurance and capital markets. Providing coverage to about 2.9 Million homeowners TCIP is the largest insurance program in the country with about 0.5 Billion USD in its own reserves and about 2.3 Billion USD in total claims paying capacity. The total payment for earthquake damage since 2000 (mostly small, 226 earthquakes) amounts to about 13 Million USD. The country-wide penetration rate is about 22%, highest in the Marmara region (30%) and lowest in the south-east Turkey (9%). TCIP is the sole-source provider of earthquake loss coverage up to 90,000 USD per house. The annual premium, categorized on the basis of earthquake zones type of structure, is about US90 for a 100 square meter reinforced concrete building in the most hazardous zone with 2% deductible. The earthquake engineering related shortcomings of the TCIP is exemplified by fact that the average rate of 0.13% (for reinforced concrete buildings) with only 2% deductible is rather low compared to countries with similar earthquake exposure. From an earthquake engineering point of view the risk underwriting (Typification of housing units to be insured, earthquake intensity zonation and the sum insured) of the TCIP needs to be overhauled. Especially for large cities, models can be developed where its expected earthquake performance (and consequently the insurance premium) can be can be assessed on the basis of the location of the unit (microzoned earthquake hazard) and basic structural attributes (earthquake vulnerability relationships). With such an approach, in the future the TCIP can contribute to the control of construction through differentiation of premia on the basis of earthquake vulnerability.

  12. FLARE: A New User Facility for Laboratory Studies of Multiple-Scale Physics of Magnetic Reconnection and Related Phenomena in Heliophysics and Astrophysics

    NASA Astrophysics Data System (ADS)

    Ji, H.; Bhattacharjee, A.; Goodman, A.; Prager, S.; Daughton, W.; Cutler, R.; Fox, W.; Hoffmann, F.; Kalish, M.; Kozub, T.; Jara-Almonte, J.; Myers, C.; Ren, Y.; Sloboda, P.; Yamada, M.; Yoo, J.; Bale, S. D.; Carter, T.; Dorfman, S.; Drake, J.; Egedal, J.; Sarff, J.; Wallace, J.

    2017-10-01

    The FLARE device (Facility for Laboratory Reconnection Experiments; flare.pppl.gov) is a new laboratory experiment under construction at Princeton with first plasmas expected in the fall of 2017, based on the design of Magnetic Reconnection Experiment (MRX; mrx.pppl.gov) with much extended parameter ranges. Its main objective is to provide an experimental platform for the studies of magnetic reconnection and related phenomena in the multiple X-line regimes directly relevant to space, solar, astrophysical and fusion plasmas. The main diagnostics is an extensive set of magnetic probe arrays, simultaneously covering multiple scales from local electron scales ( 2 mm), to intermediate ion scales ( 10 cm), and global MHD scales ( 1 m). Specific example space physics topics which can be studied on FLARE will be discussed.

  13. Altered lipid peroxidation markers are related to post-traumatic stress disorder (PTSD) and not trauma itself in earthquake survivors.

    PubMed

    Atli, Abdullah; Bulut, Mahmut; Bez, Yasin; Kaplan, İbrahim; Özdemir, Pınar Güzel; Uysal, Cem; Selçuk, Hilal; Sir, Aytekin

    2016-06-01

    The traumatic life events, including earthquakes, war, and interpersonal conflicts, cause a cascade of psychological and biological changes known as post-traumatic stress disorder (PTSD). Malondialdehyde (MDA) is a reliable marker of lipid peroxidation, and paraoxonase is a known antioxidant enzyme. The aims of this study were to investigate the relationship between earthquake trauma, PTSD effects on oxidative stress and the levels of serum paraoxonase 1 (PON1) enzyme activity, and levels of serum MDA. The study was carried out on three groups called: the PTSD group, the traumatized with earthquake exercise group, and healthy control group, which contained 32, 31, and 38 individuals, respectively. Serum MDA levels and PON1 enzyme activities from all participants were measured, and the results were compared across all groups. There were no significant differences between the PTSD patients and non-PTSD earthquake survivors in terms of the study variables. The mean PON1 enzyme activity from PTSD patients was significantly lower, while the mean MDA level was significantly higher than that of the healthy control group (p < 0.01 for both measurements). Similarly, earthquake survivors who did not develop PTSD showed higher MDA levels and lower PON1 activity when compared to healthy controls. However, the differences between these groups did not reach a statistically significant level. Increased MDA level and decreased PON1 activity measured in PTSD patients after earthquake and may suggest increased oxidative stress in these patients. The nonsignificant trends that are observed in lipid peroxidation markers of earthquake survivors may indicate higher impact of PTSD development on these markers than trauma itself. For example, PTSD diagnosis seems to add to the effect of trauma on serum MDA levels and PON1 enzyme activity. Thus, serum MDA levels and PON1 enzyme activity may serve as biochemical markers of PTSD diagnosis.

  14. Pre-seismic anomalous geomagnetic signature related to M8.3 earthquake occurred in Chile on September 16-th, 2015

    NASA Astrophysics Data System (ADS)

    Armand Stanica, Dragos, ,, Dr.; Stanica, Dumitru, ,, Dr.; Vladimirescu, Nicoleta

    2016-04-01

    In this paper, we retrospectively analyzed the geomagnetic data collected, via internet (www.intermagnet.com), on the interval 01 July-30 September 2015 at the observatories Easter Island (IMP) and Pilar (PIL), placed in Chile and Argentina, respectively, to emphasize a possible relationship between the pre-seismic anomalous behavior of the normalized function Bzn and M8.3 earthquake, that occurred in Offshore Coquimbo (Chile) on September 16-th, 2015. The daily mean distributions of the normalized function Bzn=Bz/Bperp (where Bz is vertical component of the geomagnetic field; Bperp is geomagnetic component perpendicular to the geoelectrical strike) and its standard deviation (STDEV) are performed in the ULF frequency range 0.001Hz to 0.0083Hz by using the FFT band-pass filter analysis. It was demonstrated that in pre-seismic conditions the Bzn has a significant enhancement due to the crustal electrical conductivity changes, possibly associated with the earthquake-induced rupture-processes and high-pressure fluid flow through the faulting system developed inside the foci and its neighboring area. After analyzing the anomalous values of the normalized function Bzn obtained at Easter Island and Pilar observatories, the second one taken as reference, we used a statistical analysis, based on a standardized random variable equation, to identify on 1-2 September 2015 a pre-seismic signature related to the M8.3 earthquake. The lead time was 14 days before the M8.3 earthquake occurrence. The final conclusion is that the proposed geomagnetic methodology might be used to provide suitable information for the extreme earthquake hazard assessment.

  15. Patient trends in orthopedic traumas and related disorders after tsunami caused by the Great East Japan Earthquake: An experience in the primary referral medical center.

    PubMed

    Matsuzawa, Gaku; Sano, Hirotaka; Ohnuma, Hideji; Tomiya, Akihito; Kuwahara, Yoshiyuki; Hashimoto, Chihiro; Imamura, Itaru; Ishibashi, Satoru; Kobayashi, Michio; Kobayashi, Masakazu; Ishii, Tadashi; Kaneda, Iwao; Itoi, Eiji

    2016-07-01

    In the Great East Japan Earthquake, the Japanese Red Cross Ishinomaki Hospital played an important role as a principal referral center within the Ishinomaki region, one of the most severely affected areas in eastern Japan. The present study describes the patient population, clinical characteristics, and time courses of the medical problems observed at this hospital. A retrospective survey of medical logs and records was conducted on the first 2 weeks after the earthquake to characterize orthopedic traumas and related disorders treated during this catastrophe. Patient number, severity of injuries, number of patients secondarily transported to the referral medical centers in the inland area, and the number of surgeries performed during the study period were investigated. Totally, 7686 patients visited the hospital. Of which, 1807 patients suffered from exogenous diseases, such as trauma, burns, crush syndrome, deep venous thrombosis, and infectious diseases. Patients who suffered from hypothermia were the most frequently seen within the first 2 weeks after the earthquake. Interestingly, most patients' conditions were not severe and required only simple treatments. Four patients (0.2% of patients with exogenous diseases) were secondarily transported to the referral medical centers in the inland area and only four patients were surgically treated because of a lack of available implants, surgical devices, and electric power supply. The Great East Japan Earthquake and subsequent tsunami, which occurred during an early spring afternoon, resulted in a unique orthopedic patient population, which included few severely injured patients compared with numerous deaths. We believe that each coastal region hospital should develop its own emergency medical care system to address future tsunami events while considering their surrounding environment. The information described in the present study should be important for preparation toward future events involving massive earthquakes

  16. Earthquakes, July-August 1992

    Person, W.J.

    1992-01-01

    There were two major earthquakes (7.0≤M<8.0) during this reporting period. A magnitude 7.5 earthquake occurred in Kyrgyzstan on August 19 and a magnitude 7.0 quake struck the Ascension Island region on August 28. In southern California, aftershocks of the magnitude 7.6 earthquake on June 28, 1992, continued. One of these aftershocks caused damage and injuries, and at least one other aftershock caused additional damage. Earthquake-related fatalities were reportred in Kyrgzstan and Pakistan. 

  17. ViscoSim Earthquake Simulator

    Pollitz, Fred

    2012-01-01

    Synthetic seismicity simulations have been explored by the Southern California Earthquake Center (SCEC) Earthquake Simulators Group in order to guide long‐term forecasting efforts related to the Unified California Earthquake Rupture Forecast (Tullis et al., 2012a). In this study I describe the viscoelastic earthquake simulator (ViscoSim) of Pollitz, 2009. Recapitulating to a large extent material previously presented by Pollitz (2009, 2011) I describe its implementation of synthetic ruptures and how it differs from other simulators being used by the group.

  18. Earthquake Facts

    MedlinePlus

    ... recordings of large earthquakes, scientists built large spring-pendulum seismometers in an attempt to record the long- ... are moving away from one another. The first “pendulum seismoscope” to measure the shaking of the ground ...

  19. Debris Flows and Related Phenomena

    NASA Astrophysics Data System (ADS)

    Ancey, C.

    Torrential floods are a major natural hazard, claiming thousands of lives and millions of dollars in lost property each year in almost all mountain areas on the Earth. After a catastrophic eruption of Mount St. Helen in the USA in May 1980, water from melting snow, torrential rains from the eruption cloud, and water displaced from Spirit Lake mixed with deposited ash and debris to produce very large debris flows and cause extensive damage and loss of life [1]. During the 1985 eruption of Nevado del Ruiz in Colombia, more than 20,000 people perished when a large debris flow triggered by the rapid melting of snow and ice at the volcano summit, swept through the town of Armero [2]. In 1991, the eruption of Pinatubo volcano in the Philippines disperses more than 5 cubic kilometres of volcanic ash into surrounding valleys. Much of that sediment has subsequently been mobilised as debris flows by typhoon rains and has devastated more than 300 square kilometres of agricultural land. Even, in Eur opean countries, recent events that torrential floods may have very destructive effects (Sarno and Quindici in southern Italy in May 1998, where approximately 200 people were killed). The catastrophic character of these floods in mountainous watersheds is a consequence of significant transport of materials associated with water flows. Two limiting flow regimes can be distinguished. Bed load and suspension refer to dilute transport of sediments within water. This means that water is the main agent in the flow dynamics and that the particle concentration does not exceed a few percent. Such flows are typically two-phase flows. In contrast, debris flows are mas s movements of concentrated slurries of water, fine solids, rocks and boulders. As a first approximation, debris flows can be treated as one-phase flows and their flow properties can be studied using classical rheological methods. The study of debris flows is a very exciting albeit immature science, made up of disparate elements borrowed from geomorphology, geology, hydrology, soil mechanics, and fluid mechanics. The purpose of this chapter is to provide an introduction to physical aspects of debris flows, with specific attention directed to their rheological features. Despite attempts to provide a coherent view on the topic, coverage is incomplete and the reader is referred to a series of papers and books. Three books are particularly commendable [3-5]. Some review papers provide interesting overviews, introducing the newcomers to the field to the main concepts [6-8]. The background material in rheology can be found in Chaps. 2 and 3.

  20. Earthquake watch

    Hill, M.

    1976-01-01

     When the time comes that earthquakes can be predicted accurately, what shall we do with the knowledge? This was the theme of a November 1975 conference on earthquake warning and response held in San Francisco called by Assistant Secretary of the Interior Jack W. Carlson. Invited were officials of State and local governments from Alaska, California, Hawaii, Idaho, Montana, Nevada, utah, Washington, and Wyoming and representatives of the news media. 

  1. Nowcasting Earthquakes and Tsunamis

    NASA Astrophysics Data System (ADS)

    Rundle, J. B.; Turcotte, D. L.

    2017-12-01

    The term "nowcasting" refers to the estimation of the current uncertain state of a dynamical system, whereas "forecasting" is a calculation of probabilities of future state(s). Nowcasting is a term that originated in economics and finance, referring to the process of determining the uncertain state of the economy or market indicators such as GDP at the current time by indirect means. We have applied this idea to seismically active regions, where the goal is to determine the current state of a system of faults, and its current level of progress through the earthquake cycle (http://onlinelibrary.wiley.com/doi/10.1002/2016EA000185/full). Advantages of our nowcasting method over forecasting models include: 1) Nowcasting is simply data analysis and does not involve a model having parameters that must be fit to data; 2) We use only earthquake catalog data which generally has known errors and characteristics; and 3) We use area-based analysis rather than fault-based analysis, meaning that the methods work equally well on land and in subduction zones. To use the nowcast method to estimate how far the fault system has progressed through the "cycle" of large recurring earthquakes, we use the global catalog of earthquakes, using "small" earthquakes to determine the level of hazard from "large" earthquakes in the region. We select a "small" region in which the nowcast is to be made, and compute the statistics of a much larger region around the small region. The statistics of the large region are then applied to the small region. For an application, we can define a small region around major global cities, for example a "small" circle of radius 150 km and a depth of 100 km, as well as a "large" earthquake magnitude, for example M6.0. The region of influence of such earthquakes is roughly 150 km radius x 100 km depth, which is the reason these values were selected. We can then compute and rank the seismic risk of the world's major cities in terms of their relative seismic risk

  2. The search for Infrared radiation prior to major earthquakes

    NASA Astrophysics Data System (ADS)

    Ouzounov, D.; Taylor, P.; Pulinets, S.

    2004-12-01

    This work describes our search for a relationship between tectonic stresses and electro-chemical and thermodynamic processes in the Earth and increases in mid-IR flux as part of a possible ensemble of electromagnetic (EM) phenomena that may be related to earthquake activity. Recent analysis of continuous ongoing long- wavelength Earth radiation (OLR) indicates significant and anomalous variability prior to some earthquakes. The cause of these anomalies is not well understood but could be the result of a triggering by an interaction between the lithosphere-hydrosphere and atmospheric related to changes in the near surface electrical field and gas composition prior to the earthquake. The OLR anomaly covers large areas surrounding the main epicenter. We have use the NOAA IR data to differentiate between the global and seasonal variability and these transient local anomalies. Indeed, on the basis of a temporal and spatial distribution analysis, an anomaly pattern is found to occur several days prior some major earthquakes. The significance of these observations was explored using data sets of some recent worldwide events.

  3. Earthquake Related Variation of Total Electron Content in Ionosphere over Chinese Mainland Derived from Observations of a Nationwide GNSS Network

    NASA Astrophysics Data System (ADS)

    Gan, Weijun

    2016-07-01

    Crustal Movement Observation Network of China (CMONOC) is a key national scientific infrastructure project carried out during 1997-2012 with 2 phases. The network is composed of 260 continuously observed GNSS stations (CORS) and 2081 campaign mode GNSS stations, with the main purpose to monitor the crustal movement, perceptible water vapor (PWV), total electron content (TEC), and many other tectonic and environmental elements around mainland China, by mainly using the Global Navigation Satellite System (GNSS) technology. Here, based on the GNSS data of 260 CORS of COMNOC for about 5 years, we investigated the characteristics of TEC in ionosphere over Chinese Mainland and discussed if there was any abnormal change of TEC before and after a big earthquake. our preliminary results show that it is hard to see any convincing precursor of TEC before a big earthquake. However, the huge energy released by a big earthquake can obviously disturb the TEC over meizoseismal area.

  4. Revealing the deformational anomalies based on GNSS data in relation to the preparation and stress release of large earthquakes

    NASA Astrophysics Data System (ADS)

    Kaftan, V. I.; Melnikov, A. Yu.

    2018-01-01

    The results of Global Navigational Satellite System (GNSS) observations in the regions of large earthquakes are analyzed. The characteristics of the Earth's surface deformations before, during, and after the earthquakes are considered. The obtained results demonstrate the presence of anomalous deformations close to the epicenters of the events. Statistical estimates of the anomalous strains and their relationship with measurement errors are obtained. Conclusions are drawn about the probable use of local GNSS networks to assess the risk of the occurrence of strong seismic events.

  5. Earthquakes March-April 1992

    Person, Waverly J.

    1992-01-01

    The months of March and April were quite active seismically speaking. There was one major earthquake (7.0Earthquake-related deaths were reported in Iran, Costa Rica, Turkey, and Germany.

  6. Earthquake Source Mechanics

    NASA Astrophysics Data System (ADS)

    The past 2 decades have seen substantial progress in our understanding of the nature of the earthquake faulting process, but increasingly, the subject has become an interdisciplinary one. Thus, although the observation of radiated seismic waves remains the primary tool for studying earthquakes (and has been increasingly focused on extracting the physical processes occurring in the “source”), geological studies have also begun to play a more important role in understanding the faulting process. Additionally, defining the physical underpinning for these phenomena has come to be an important subject in experimental and theoretical rock mechanics.In recognition of this, a Maurice Ewing Symposium was held at Arden House, Harriman, N.Y. (the former home of the great American statesman Averill Harriman), May 20-23, 1985. The purpose of the meeting was to bring together the international community of experimentalists, theoreticians, and observationalists who are engaged in the study of various aspects of earthquake source mechanics. The conference was attended by more than 60 scientists from nine countries (France, Italy, Japan, Poland, China, the United Kingdom, United States, Soviet Union, and the Federal Republic of Germany).

  7. Earthquakes for Kids

    MedlinePlus

    ... across a fault to learn about past earthquakes. Science Fair Projects A GPS instrument measures slow movements of the ground. Become an Earthquake Scientist Cool Earthquake Facts Today in Earthquake History A scientist stands in ...

  8. 2010 Chile Earthquake Aftershock Response

    NASA Astrophysics Data System (ADS)

    Barientos, Sergio

    2010-05-01

    The Mw=8.8 earthquake off the coast of Chile on 27 February 2010 is the 5th largest megathrust earthquake ever to be recorded and provides an unprecedented opportunity to advance our understanding of megathrust earthquakes and associated phenomena. The 2010 Chile earthquake ruptured the Concepcion-Constitucion segment of the Nazca/South America plate boundary, south of the Central Chile region and triggered a tsunami along the coast. Following the 2010 earthquake, a very energetic aftershock sequence is being observed in an area that is 600 km along strike from Valparaiso to 150 km south of Concepcion. Within the first three weeks there were over 260 aftershocks with magnitude 5.0 or greater and 18 with magnitude 6.0 or greater (NEIC, USGS). The Concepcion-Constitucion segment lies immediately north of the rupture zone associated with the great magnitude 9.5 Chile earthquake, and south of the 1906 and the 1985 Valparaiso earthquakes. The last great subduction earthquake in the region dates back to the February 1835 event described by Darwin (1871). Since 1835, part of the region was affected in the north by the Talca earthquake in December 1928, interpreted as a shallow dipping thrust event, and by the Chillan earthquake (Mw 7.9, January 1939), a slab-pull intermediate depth earthquake. For the last 30 years, geodetic studies in this area were consistent with a fully coupled elastic loading of the subduction interface at depth; this led to identify the area as a mature seismic gap with potential for an earthquake of magnitude of the order 8.5 or several earthquakes of lesser magnitude. What was less expected was the partial rupturing of the 1985 segment toward north. Today, the 2010 earthquake raises some disturbing questions: Why and how the rupture terminated where it did at the northern end? How did the 2010 earthquake load the adjacent segment to the north and did the 1985 earthquake only partially ruptured the plate interface leaving loaded asperities since

  9. Department of Energy Natural Phenomena Hazards Mitigation Program

    SciT

    Murray, R.C.

    1993-09-01

    This paper will present a summary of past and present accomplishments of the Natural Phenomena Hazards Program that has been ongoing at Lawrence Livermore National Laboratory since 1975. The Natural Phenomena covered includes earthquake; winds, hurricanes, and tornadoes; flooding and precipitation; lightning; and volcanic events. The work is organized into four major areas (1) Policy, requirements, standards, and guidance (2) Technical support, research development, (3) Technology transfer, and (4) Oversight.

  10. Foot morphometric phenomena.

    PubMed

    Agić, Ante

    2007-06-01

    Knowledge of the foot morphometry is important for proper foot structure and function. Foot structure as a vital part of human body is important for many reasons. The foot anthropometric and morphology phenomena are analyzed together with hidden biomechanical descriptors in order to fully characterize foot functionality. For Croatian student population the scatter data of the individual foot variables were interpolated by multivariate statistics. Foot morphometric descriptors are influenced by many factors, such as life style, climate, and things of great importance in human society. Dominant descriptors related to fit and comfort are determined by the use 3D foot shape and advanced foot biomechanics. Some practical recommendations and conclusions for medical, sportswear and footwear practice are highlighted.

  11. An earthquake history derived from stratigraphic and microfossil evidence of relative sea-level change at Coos Bay, southern coastal Oregon

    Nelson, A.R.; Jennings, A.E.; Kashima, K.

    1996-01-01

    Much of the uncertainty in determining the number and magnitude of past great earthquakes in the Cascadia subduction zone of western North America stems from difficulties in using estuarine stratigraphy to infer the size and rate of late Holocene relative sea-level changes. A sequence of interbedded peaty and muddy intertidal sediment beneath a small, protected tidal marsh in a narrow inlet of Coos Bay, Oregon, records ten rapid to instantaneous rises in relative sea level. Each rise is marked by a contact that records an upward transition from peaty to muddy sediment. But only two contacts, dating from about 1700 and 2300 yr ago, show the site-wide extent and abrupt changes in lithology and foraminiferal and diatom assemblages that can be used to infer at least half a meter of sudden coseismic subsidence. Although the characteristics of a third, gradual contact do not differ from those of some contacts produced by nonseismic processes, regional correlation with other similar sequences and high-precision 14C dating suggest that the third contact records a great plate-boundary earthquake about 300 yr ago. A fourth contact formed too slowly to have been caused by coseismic subsidence. Because lithologic and microfossil data are not sufficient to distinguish a coseismic from a nonseismic origin for the other six peatmud contacts, we cannot determine earthquake recurrence intervals at this site. Similar uncertainties in great earthquake recurrence and magnitude prevail at similar sites elsewhere in the Cascadia subduction zone, except those with sequences showing changes in fossils indicative of > 1 m of sudden subsidence, sand sheets deposited by tsunamis, or liquefaction features.

  12. Characteristics of broadband slow earthquakes explained by a Brownian model

    NASA Astrophysics Data System (ADS)

    Ide, S.; Takeo, A.

    2017-12-01

    Brownian slow earthquake (BSE) model (Ide, 2008; 2010) is a stochastic model for the temporal change of seismic moment release by slow earthquakes, which can be considered as a broadband phenomena including tectonic tremors, low frequency earthquakes, and very low frequency (VLF) earthquakes in the seismological frequency range, and slow slip events in geodetic range. Although the concept of broadband slow earthquake may not have been widely accepted, most of recent observations are consistent with this concept. Then, we review the characteristics of slow earthquakes and how they are explained by BSE model. In BSE model, the characteristic size of slow earthquake source is represented by a random variable, changed by a Gaussian fluctuation added at every time step. The model also includes a time constant, which divides the model behavior into short- and long-time regimes. In nature, the time constant corresponds to the spatial limit of tremor/SSE zone. In the long-time regime, the seismic moment rate is constant, which explains the moment-duration scaling law (Ide et al., 2007). For a shorter duration, the moment rate increases with size, as often observed for VLF earthquakes (Ide et al., 2008). The ratio between seismic energy and seismic moment is constant, as shown in Japan, Cascadia, and Mexico (Maury et al., 2017). The moment rate spectrum has a section of -1 slope, limited by two frequencies corresponding to the above time constant and the time increment of the stochastic process. Such broadband spectra have been observed for slow earthquakes near the trench axis (Kaneko et al., 2017). This spectrum also explains why we can obtain VLF signals by stacking broadband seismograms relative to tremor occurrence (e.g., Takeo et al., 2010; Ide and Yabe, 2014). The fluctuation in BSE model can be non-Gaussian, as far as the variance is finite, as supported by the central limit theorem. Recent observations suggest that tremors and LFEs are spatially characteristic

  13. Some comparisons between mining-induced and laboratory earthquakes

    McGarr, A.

    1994-01-01

    Although laboratory stick-slip friction experiments have long been regarded as analogs to natural crustal earthquakes, the potential use of laboratory results for understanding the earthquake source mechanism has not been fully exploited because of essential difficulties in relating seismographic data to measurements made in the controlled laboratory environment. Mining-induced earthquakes, however, provide a means of calibrating the seismic data in terms of laboratory results because, in contrast to natural earthquakes, the causative forces as well as the hypocentral conditions are known. A comparison of stick-slip friction events in a large granite sample with mining-induced earthquakes in South Africa and Canada indicates both similarities and differences between the two phenomena. The physics of unstable fault slip appears to be largely the same for both types of events. For example, both laboratory and mining-induced earthquakes have very low seismic efficiencies {Mathematical expression} where ??a is the apparent stress and {Mathematical expression} is the average stress acting on the fault plane to cause slip; nearly all of the energy released by faulting is consumed in overcoming friction. In more detail, the mining-induced earthquakes differ from the laboratory events in the behavior of ?? as a function of seismic moment M0. Whereas for the laboratory events ?????0.06 independent of M0, ?? depends quite strongly on M0 for each set of induced earthquakes, with 0.06 serving, apparently, as an upper bound. It seems most likely that this observed scaling difference is due to variations in slip distribution over the fault plane. In the laboratory, a stick-slip event entails homogeneous slip over a fault of fixed area. For each set of induced earthquakes, the fault area appears to be approximately fixed but the slip is inhomogeneous due presumably to barriers (zones of no slip) distributed over the fault plane; at constant {Mathematical expression}, larger

  14. Predictability of Landslide Timing From Quasi-Periodic Precursory Earthquakes

    NASA Astrophysics Data System (ADS)

    Bell, Andrew F.

    2018-02-01

    Accelerating rates of geophysical signals are observed before a range of material failure phenomena. They provide insights into the physical processes controlling failure and the basis for failure forecasts. However, examples of accelerating seismicity before landslides are rare, and their behavior and forecasting potential are largely unknown. Here I use a Bayesian methodology to apply a novel gamma point process model to investigate a sequence of quasiperiodic repeating earthquakes preceding a large landslide at Nuugaatsiaq in Greenland in June 2017. The evolution in earthquake rate is best explained by an inverse power law increase with time toward failure, as predicted by material failure theory. However, the commonly accepted power law exponent value of 1.0 is inconsistent with the data. Instead, the mean posterior value of 0.71 indicates a particularly rapid acceleration toward failure and suggests that only relatively short warning times may be possible for similar landslides in future.

  15. Initiation process of earthquakes and its implications for seismic hazard reduction strategy.

    PubMed Central

    Kanamori, H

    1996-01-01

    For the average citizen and the public, "earthquake prediction" means "short-term prediction," a prediction of a specific earthquake on a relatively short time scale. Such prediction must specify the time, place, and magnitude of the earthquake in question with sufficiently high reliability. For this type of prediction, one must rely on some short-term precursors. Examinations of strain changes just before large earthquakes suggest that consistent detection of such precursory strain changes cannot be expected. Other precursory phenomena such as foreshocks and nonseismological anomalies do not occur consistently either. Thus, reliable short-term prediction would be very difficult. Although short-term predictions with large uncertainties could be useful for some areas if their social and economic environments can tolerate false alarms, such predictions would be impractical for most modern industrialized cities. A strategy for effective seismic hazard reduction is to take full advantage of the recent technical advancements in seismology, computers, and communication. In highly industrialized communities, rapid earthquake information is critically important for emergency services agencies, utilities, communications, financial companies, and media to make quick reports and damage estimates and to determine where emergency response is most needed. Long-term forecast, or prognosis, of earthquakes is important for development of realistic building codes, retrofitting existing structures, and land-use planning, but the distinction between short-term and long-term predictions needs to be clearly communicated to the public to avoid misunderstanding. Images Fig. 8 PMID:11607657

  16. Initiation process of earthquakes and its implications for seismic hazard reduction strategy.

    PubMed

    Kanamori, H

    1996-04-30

    For the average citizen and the public, "earthquake prediction" means "short-term prediction," a prediction of a specific earthquake on a relatively short time scale. Such prediction must specify the time, place, and magnitude of the earthquake in question with sufficiently high reliability. For this type of prediction, one must rely on some short-term precursors. Examinations of strain changes just before large earthquakes suggest that consistent detection of such precursory strain changes cannot be expected. Other precursory phenomena such as foreshocks and nonseismological anomalies do not occur consistently either. Thus, reliable short-term prediction would be very difficult. Although short-term predictions with large uncertainties could be useful for some areas if their social and economic environments can tolerate false alarms, such predictions would be impractical for most modern industrialized cities. A strategy for effective seismic hazard reduction is to take full advantage of the recent technical advancements in seismology, computers, and communication. In highly industrialized communities, rapid earthquake information is critically important for emergency services agencies, utilities, communications, financial companies, and media to make quick reports and damage estimates and to determine where emergency response is most needed. Long-term forecast, or prognosis, of earthquakes is important for development of realistic building codes, retrofitting existing structures, and land-use planning, but the distinction between short-term and long-term predictions needs to be clearly communicated to the public to avoid misunderstanding.

  17. Teaching optical phenomena with Tracker

    NASA Astrophysics Data System (ADS)

    Rodrigues, M.; Simeão Carvalho, P.

    2014-11-01

    Since the invention and dissemination of domestic laser pointers, observing optical phenomena is a relatively easy task. Any student can buy a laser and experience at home, in a qualitative way, the reflection, refraction and even diffraction phenomena of light. However, quantitative experiments need instruments of high precision that have a relatively complex setup. Fortunately, nowadays it is possible to analyse optical phenomena in a simple and quantitative way using the freeware video analysis software ‘Tracker’. In this paper, we show the advantages of video-based experimental activities for teaching concepts in optics. We intend to show: (a) how easy the study of such phenomena can be, even at home, because only simple materials are needed, and Tracker provides the necessary measuring instruments; and (b) how we can use Tracker to improve students’ understanding of some optical concepts. We give examples using video modelling to study the laws of reflection, Snell’s laws, focal distances in lenses and mirrors, and diffraction phenomena, which we hope will motivate teachers to implement it in their own classes and schools.

  18. Crystallization phenomena in slags

    NASA Astrophysics Data System (ADS)

    Orrling, Carl Folke

    2000-09-01

    The crystallization of the mold slag affects both the heat transfer and the lubrication between the mold and the strand in continuous casting of steel. In order for mold slag design to become an engineering science rather than an empirical exercise, a fundamental understanding of the melting and solidification behavior of a slag must be developed. Thus it is necessary to be able to quantify the phenomena that occur under the thermal conditions that are found in the mold of a continuous caster. The double hot thermocouple technique (DHTT) and the Confocal Laser Scanning Microscope used in this study are two novel techniques for investigating melting and solidification phenomena of transparent slags. Results from these techniques are useful in defining the phenomena that occur when the slag film infiltrates between the mold and the shell of the casting. TTT diagrams were obtained for various slags and indicated that the onset of crystallization is a function of cooling rate and slag chemistry. Crystal morphology was found to be dependent upon the experimental temperature and four different morphologies were classified based upon the degree of melt undercooling. Continuous cooling experiments were carried out to develop CCT diagrams and it was found that the amount and appearance of the crystalline fraction greatly depends on the cooling conditions. The DHTT can also be used to mimic the cooling profile encountered by the slag in the mold of a continuous caster. In this differential cooling mode (DCT), it was found that the details of the cooling rate determine the actual response of the slag to a thermal gradient and small changes can lead to significantly different results. Crystal growth rates were measured and found to be in the range between 0.11 mum/s to 11.73 mum/s depending on temperature and slag chemistry. Alumina particles were found to be effective innoculants in oxide melts reducing the incubation time for the onset of crystallization and also extending

  19. Distribution and migration of aftershocks of the 2010 Mw 7.4 Ogasawara Islands intraplate normal-faulting earthquake related to a fracture zone in the Pacific plate

    NASA Astrophysics Data System (ADS)

    Obana, Koichiro; Takahashi, Tsutomu; No, Tetsuo; Kaiho, Yuka; Kodaira, Shuichi; Yamashita, Mikiya; Sato, Takeshi; Nakamura, Takeshi

    2014-04-01

    describe the aftershocks of a Mw 7.4 intraplate normal-faulting earthquake that occurred 150 km east Ogasawara (Bonin) Islands, Japan, on 21 December 2010. It occurred beneath the outer trench slope of the Izu-Ogasawara trench, where the Pacific plate subducts beneath the Philippine Sea plate. Aftershock observations using ocean bottom seismographs (OBSs) began soon after the earthquake and multichannel seismic reflection surveys were conducted across the aftershock area. Aftershocks were distributed in a NW-SE belt 140 km long, oblique to the N-S trench axis. They formed three subparallel lineations along a fracture zone in the Pacific plate. The OBS observations combined with data from stations on Chichi-jima and Haha-jima Islands revealed a migration of the aftershock activity. The first hour, which likely outlines the main shock rupture, was limited to an 80 km long area in the central part of the subsequent aftershock area. The first hour activity occurred mainly around, and appears to have been influenced by, nearby large seamounts and oceanic plateau, such as the Ogasawara Plateau and the Uyeda Ridge. Over the following days, the aftershocks expanded beyond or into these seamounts and plateau. The aftershock distribution and migration suggest that crustal heterogeneities related to a fracture zone and large seamounts and oceanic plateau in the incoming Pacific plate affected the rupture of the main shock. Such preexisting structures may influence intraplate normal-faulting earthquakes in other regions of plate flexure prior to subduction.

  20. Earthquake impact scale

    Wald, D.J.; Jaiswal, K.S.; Marano, K.D.; Bausch, D.

    2011-01-01

    With the advent of the USGS prompt assessment of global earthquakes for response (PAGER) system, which rapidly assesses earthquake impacts, U.S. and international earthquake responders are reconsidering their automatic alert and activation levels and response procedures. To help facilitate rapid and appropriate earthquake response, an Earthquake Impact Scale (EIS) is proposed on the basis of two complementary criteria. On the basis of the estimated cost of damage, one is most suitable for domestic events; the other, on the basis of estimated ranges of fatalities, is generally more appropriate for global events, particularly in developing countries. Simple thresholds, derived from the systematic analysis of past earthquake impact and associated response levels, are quite effective in communicating predicted impact and response needed after an event through alerts of green (little or no impact), yellow (regional impact and response), orange (national-scale impact and response), and red (international response). Corresponding fatality thresholds for yellow, orange, and red alert levels are 1, 100, and 1,000, respectively. For damage impact, yellow, orange, and red thresholds are triggered by estimated losses reaching $1M, $100M, and $1B, respectively. The rationale for a dual approach to earthquake alerting stems from the recognition that relatively high fatalities, injuries, and homelessness predominate in countries in which local building practices typically lend themselves to high collapse and casualty rates, and these impacts lend to prioritization for international response. In contrast, financial and overall societal impacts often trigger the level of response in regions or countries in which prevalent earthquake resistant construction practices greatly reduce building collapse and resulting fatalities. Any newly devised alert, whether economic- or casualty-based, should be intuitive and consistent with established lexicons and procedures. Useful alerts should

  1. Strain buildup and release, earthquake prediction and selection of VBL sites for margins of the north Pacific

    NASA Technical Reports Server (NTRS)

    Scholz, C. H.; Bilham, R.; Johnson, T. L.

    1981-01-01

    During the past year, the grant supported research on several aspects of crustal deformation. The relation between earthquake displacements and fault dimensions was studied in an effort to find scaling laws that relate static parameters such as slip and stress drop to the dimensions of the rupture. Several implications of the static relations for the dynamic properties of earthquakes such as rupture velocity and dynamic stress drop were proposed. A theoretical basis for earthquake related phenomena associated with slow rupture growth or propagation, such as delayed multiple events, was developed using the stress intensity factor defined in fracture mechanics and experimental evidence from studies of crack growth by stress corrosion. Finally, extensive studies by Japanese geologists have established the offset across numerous faults in Japan over the last one hundred thousand years. These observations of intraplate faulting are being used to establish the spatial variations of the average strain rate of subregions in southern Japan.

  2. Earthquake lights and the stress-activation of positive hole charge carriers in rocks

    St-Laurent, F.; Derr, J.S.; Freund, F.T.

    2006-01-01

    Earthquake-related luminous phenomena (also known as earthquake lights) may arise from (1) the stress-activation of positive hole (p-hole) charge carriers in igneous rocks and (2) the accumulation of high charge carrier concentrations at asperities in the crust where the stress rates increase very rapidly as an earthquake approaches. It is proposed that, when a critical charge carrier concentration is reached, the p-holes form a degenerated solid state plasma that can break out of the confined rock volume and propagate as a rapidly expanding charge cloud. Upon reaching the surface the charge cloud causes dielectric breakdown at the air-rock interface, i.e. corona discharges, accompanied by the emission of light and high frequency electromagnetic radiation. ?? 2006 Elsevier Ltd. All rights reserved.

  3. Specific variations of air temperature and relative humidity around the time of Michoacan earthquake M8.1 Sept. 19, 1985 as a possible indicator of interaction between tectonic plates

    NASA Astrophysics Data System (ADS)

    Pulinets, S. A.; Dunajecka, M. A.

    2007-02-01

    The recent development of the Lithosphere-Atmosphere-Ionosphere (LAI) coupling model and experimental data of remote sensing satellites on thermal anomalies before major strong earthquakes have demonstrated that radon emanations in the area of earthquake preparation can produce variations of the air temperature and relative humidity. Specific repeating pattern of humidity and air temperature variations was revealed as a result of analysis of the meteorological data for several tens of strong earthquakes all over the world. The main physical process responsible for the observed variations is the latent heat release due to water vapor condensation on ions produced as a result of air ionization by energetic α-particles emitted by 222Rn. The high effectiveness of this process was proved by the laboratory and field experiments; hence the specific variations of air humidity and temperature can be used as indicator of radon variations before earthquakes. We analyzed the historical meteorological data all over the Mexico around the time of one of the most destructive earthquakes (Michoacan earthquake M8.1) that affected the Mexico City on September 19, 1985. Several distinct zones of specific variations of the air temperature and relative humidity were revealed that may indicate the different character of radon variations in different parts of Mexico before the Michoacan earthquake. The most interesting result on the specific variations of atmosphere parameters was obtained at Baja California region close to the border of Cocos and Rivera tectonic plates. This result demonstrates the possibility of the increased radon variations not only in the vicinity of the earthquake source but also at the border of interacting tectonic plates. Recent results on Thermal InfraRed (TIR) anomalies registered by Meteosat 5 before the Gujarat earthquake M7.9 on 26 of January 2001 supports the idea on the possibility of thermal effects at the border of interacting tectonic plates.

  4. Simultaneous infrasonic, seismic, magnetic and ionospheric observations in an earthquake epicentre

    NASA Astrophysics Data System (ADS)

    Laštovička, J.; Baše, J.; Hruška, F.; Chum, J.; Šindelářová, T.; Horálek, J.; Zedník, J.; Krasnov, V.

    2010-10-01

    Various pre-seismic and co-seismic effects have been reported in the literature in the solid Earth, hydrosphere, atmosphere, electric/magnetic field and in the ionosphere. Some of the effects observed above the surface, particularly some of the pre-seismic effects, are still a matter of debate. Here we analyze the co-seismic effects of a relatively weak earthquake of 28 October 2008, which was a part of an earthquake swarm in the westernmost region of the Czech Republic. Special attention is paid to unique measurements of infrasonic phenomena. As far as we know, these have been the first infrasonic measurements during earthquake in the epicentre zone. Infrasonic oscillations (˜1-12 Hz) in the epicentre region appear to be excited essentially by the vertical seismic oscillations. The observed oscillations are real epicentral infrasound not caused by seismic shaking of the instruments or by meteorological phenomena. Seismo-infrasonic oscillations observed 155 km apart from the epicentre were excited in situ by seismic waves. No earthquake-related infrasonic effects have been observed in the ionosphere. Necessity to make vibration tests of instruments is pointed out in order to be sure that observed effects are not effects of mechanical shaking of the instrument.

  5. Relationships between mental health distress and work-related factors among prefectural public servants two months after the Great East Japan Earthquake.

    PubMed

    Fukasawa, Maiko; Suzuki, Yuriko; Obara, Akiko; Kim, Yoshiharu

    2015-02-01

    In times of disaster, public servants face multiple burdens as they engage in a demanding and stressful disaster-response work while managing their own needs caused by the disaster. We investigated the effects of work-related factors on the mental health of prefectural public servants working in the area devastated by the Great East Japan Earthquake to identify some ideas for organizational work modifications to protect their mental health. Two months after the earthquake, Miyagi prefecture conducted a self-administered health survey of prefectural public servants and obtained 4,331 (82.8%) valid responses. We investigated relationships between mental health distress (defined as K6 ≥ 13) and work-related variables (i.e., job type, overwork, and working environment) stratified by level of earthquake damage experienced. The proportion of participants with mental health distress was 3.0% in the group that experienced less damage and 5.9% in the group that experienced severe damage. In the group that experienced less damage, working >100 h of overtime per month (adjusted odds ratio [OR], 2.06; 95% confidence interval [CI], 1.11-3.82) and poor workplace communication (adjusted OR, 10.96; 95% CI, 6.63-18.09) increased the risk of mental health distress. In the group that experienced severe damage, handling residents' complaints (adjusted OR, 4.79; 95% CI, 1.55-14.82) and poor workplace communication (adjusted OR, 9.14; 95% CI, 3.34-24.97) increased the risk, whereas involvement in disaster-related work (adjusted OR, 0.39; 95% CI, 0.18-0.86) decreased the risk. Workers who have experienced less disaster-related damage might benefit from working fewer overtime hours, and those who have experienced severe damage might benefit from avoiding contact with residents and engaging in disaster-related work. Facilitating workplace communication appeared important for both groups of workers.

  6. Intermediate-term earthquake prediction

    Knopoff, L.

    1990-01-01

    The problems in predicting earthquakes have been attacked by phenomenological methods from pre-historic times to the present. The associations of presumed precursors with large earthquakes often have been remarked upon. the difficulty in identifying whether such correlations are due to some chance coincidence or are real precursors is that usually one notes the associations only in the relatively short time intervals before the large events. Only rarely, if ever, is notice taken of whether the presumed precursor is to be found in the rather long intervals that follow large earthquakes, or in fact is absent in these post-earthquake intervals. If there are enough examples, the presumed correlation fails as a precursor in the former case, while in the latter case the precursor would be verified. Unfortunately, the observer is usually not concerned with the 'uniteresting' intervals that have no large earthquakes

  7. Earthquake Simulator Finds Tremor Triggers

    Johnson, Paul

    2018-01-16

    Using a novel device that simulates earthquakes in a laboratory setting, a Los Alamos researcher has found that seismic waves-the sounds radiated from earthquakes-can induce earthquake aftershocks, often long after a quake has subsided. The research provides insight into how earthquakes may be triggered and how they recur. Los Alamos researcher Paul Johnson and colleague Chris Marone at Penn State have discovered how wave energy can be stored in certain types of granular materials-like the type found along certain fault lines across the globe-and how this stored energy can suddenly be released as an earthquake when hit by relatively small seismic waves far beyond the traditional “aftershock zone” of a main quake. Perhaps most surprising, researchers have found that the release of energy can occur minutes, hours, or even days after the sound waves pass; the cause of the delay remains a tantalizing mystery.

  8. Spatial variations in fault friction related to lithology from rupture and afterslip of the 2014 South Napa, California, earthquake

    Michael Floyd,; Richard Walters,; John Elliot,; Funning, Gareth J.; Svarc, Jerry L.; Murray, Jessica R.; Andy Hooper,; Yngvar Larsen,; Petar Marinkovic,; Bürgmann, Roland; Johanson, Ingrid; Tim Wright,

    2016-01-01

    Following earthquakes, faults are often observed to continue slipping aseismically. It has been proposed that this afterslip occurs on parts of the fault with rate-strengthening friction that are stressed by the mainshock, but our understanding has been limited by a lack of immediate, high-resolution observations. Here we show that the behavior of afterslip following the 2014 South Napa earthquake varied over distances of only a few kilometers. This variability cannot be explained by coseismic stress changes alone. We present daily positions from continuous and survey GPS sites that we re-measured within 12 hours of the mainshock, and surface displacements from the new Sentinel-1 radar mission. This unique geodetic data set constrains the distribution and evolution of coseismic and postseismic fault slip with exceptional resolution in space and time. We suggest that the observed heterogeneity in behavior is caused by lithological controls on the frictional properties of the fault plane.

  9. Surface Deformation Due to the May 27, 1995 Sakhalin Earthquake and Related Events Measured by JERS-1 SAR Interferometry

    NASA Technical Reports Server (NTRS)

    Fielding, E. J.; Fujiwara, Satoshi; Hensley, S.; Rosen, P. A.; Tobita, Mikio; Shimada, Masanobu

    1996-01-01

    A large (M&subw;=7.0) earthquake on May 27, 1995 completely destroyed the town of Neftegorsk in the northern part of Sakhalin Island and caused more than 2000 human deaths. The shallow, right-lateral, strick-slip earthquake resulted in extensive surface ruptures and up to 7 m of horizontal displacement as reported by field workers. The sourthern part of the mainshock epicenter zone was imaged by the JERS-1 SAR (synthetic aperature radar) one month (April 28) before and two weeks after (June 11) the mainshock. Despite drastically changed surface conditions in the 44 days between the two images, due primarily to spring thaw, we obtained reasonably good interferometric correlation with the L-band (24 cm) SAR pair. The interoferogram records the distribution of deformation reflecting displacement during both the mainshock and aftershocks. The ability to map the deformation pattern can aid the assessment and mitigation of damage.

  10. Båth's law and its relation to the tectonic environment: A case study for earthquakes in Mexico

    NASA Astrophysics Data System (ADS)

    Rodríguez-Pérez, Q.; Zúñiga, F. R.

    2016-09-01

    We studied 66 mainshocks and their largest aftershocks in the Mexican subduction zone and in the Gulf of California with magnitudes in the range of 5.2 < Mw < 8.0 from 1932 to 2015. Three different types of earthquakes were analyzed: shallow thrust interplate, intermediate-depth inslab and transform strike-slip earthquakes (26, 19 and 21 events, respectively). We focus on observational aspects of the Båth's law. By studying the magnitude difference, energy ratios and energy partitioning of the mainshock-largest aftershock sequences, we analyze the physics of the mainshock-largest aftershock relationship (Båth's law). The partitioning of energy during a mainshock-aftershock sequence shows that about 96-97% of the energy dissipated in a sequence is associated with the mainshock and the rest is due to aftershocks. Our results for radiated seismic energy and energy-to-moment ratio are partially in agreement with worldwide studies supporting the observation of mechanism dependence of radiated seismic energy. The statistical tests indicate that the only significant difference is for shallow thrust and strike-slip events for these parameters. The statistical comparison of stress drop of shallow thrust versus that of inslab events shows a strongly significant difference with a confidence better than 99%. The comparison of stress drop of shallow thrust events with that of strike-slip events, also indicates a strongly significant difference. We see no dependence of stress drop with magnitude, which is strong evidence of earthquake self-similarity. We do not observe a systematic depth dependence of stress drop. The results also reveal differences in the earthquake rupture among the events. The magnitude difference between the mainshock and the largest aftershock for inslab events is larger than interplate and strike-slip events suggesting focal mechanism dependence of Båth's law. For the case of this parameter, only that for inslab and strike-slip events present a

  11. Understanding Earthquakes

    ERIC Educational Resources Information Center

    Davis, Amanda; Gray, Ron

    2018-01-01

    December 26, 2004 was one of the deadliest days in modern history, when a 9.3 magnitude earthquake--the third largest ever recorded--struck off the coast of Sumatra in Indonesia (National Centers for Environmental Information 2014). The massive quake lasted at least 10 minutes and devastated the Indian Ocean. The quake displaced an estimated…

  12. Earthquake Testing

    NASA Technical Reports Server (NTRS)

    1979-01-01

    During NASA's Apollo program, it was necessary to subject the mammoth Saturn V launch vehicle to extremely forceful vibrations to assure the moonbooster's structural integrity in flight. Marshall Space Flight Center assigned vibration testing to a contractor, the Scientific Services and Systems Group of Wyle Laboratories, Norco, California. Wyle-3S, as the group is known, built a large facility at Huntsville, Alabama, and equipped it with an enormously forceful shock and vibration system to simulate the liftoff stresses the Saturn V would encounter. Saturn V is no longer in service, but Wyle-3S has found spinoff utility for its vibration facility. It is now being used to simulate earthquake effects on various kinds of equipment, principally equipment intended for use in nuclear power generation. Government regulations require that such equipment demonstrate its ability to survive earthquake conditions. In upper left photo, Wyle3S is preparing to conduct an earthquake test on a 25ton diesel generator built by Atlas Polar Company, Ltd., Toronto, Canada, for emergency use in a Canadian nuclear power plant. Being readied for test in the lower left photo is a large circuit breaker to be used by Duke Power Company, Charlotte, North Carolina. Electro-hydraulic and electro-dynamic shakers in and around the pit simulate earthquake forces.

  13. Oral health-related quality of life and related factors among residents in a disaster area of the Great East Japan Earthquake and giant tsunami.

    PubMed

    Kishi, Mitsuo; Aizawa, Fumie; Matsui, Miki; Yokoyama, Yukari; Abe, Akiko; Minami, Kentaro; Suzuki, Ruriko; Miura, Hiroyuki; Sakata, Kiyomi; Ogawa, Akira

    2015-09-15

    Oral health is one of the most important issues for disaster survivors. The aim of this study was to determine post-disaster distribution of oral health-related quality of life (OHRQoL) and related factors in survivors of the Great East Japan Earthquake and Tsunami. Questionnaires to assess OHRQoL, psychological distress, disaster-related experiences, and current systemic-health and economic conditions were sent to survivors over 18 years of age living in Otsuchi, one of the most severely damaged municipalities. OHRQoL and psychological distress were assessed using the General Oral Health Assessment Index (GOHAI) and the Kessler Psychological Distress Scale (K6), Japanese version, respectively. Among 11,411 residents, 1,987 returned the questionnaire (response rate, 17.4%) and received an oral examination to determine number of present teeth, dental caries status, and tooth-mobility grade, and to assess periodontal health using the Community Periodontal Index. Relationships between GOHAI and related factors were examined by nonparametric bivariate and multinomial logistic regression analyses using GOHAI cutoff points at the 25(th) and 50(th) national standard percentiles. GOHAI scores were significantly lower in the 50-69-age group compared with other age groups in this study and compared with the national standard score. In bivariate analyses, all factors assessed in this study (i.e., sex, age, evacuation from home, interruption of dental treatment, lost or fractured dentures, self-rated systemic health, serious psychological distress (SPD), economic status, number of teeth, having decayed teeth, CPI code, and tooth mobility) were significantly associated with OHRQoL. Subsequent multinomial logistic regression analyses revealed that participants of upper-middle age, who had received dental treatment before the disaster, who had lost or fractured dentures, and who had clinical oral health problems were likely to show low levels of OHRQoL. In addition, perceived

  14. Local observations of the onset of a large earthquake: 28 June 1992 Landers, California

    Abercrombie, Richael; Mori, Jim

    1994-01-01

    The Landers earthquake (MW 7.3) of 28 June 1992 had a very emergent onset. The first large amplitude arrivals are delayed by about 3 sec with respect to the origin time, and are preceded by smaller-scale slip. Other large earthquakes have been observed to have similar emergent onsets, but the Landers event is one of the first to be well recorded on nearby stations. We used these recordings to investigate the spatial relationship between the hypocenter and the onset of the large energy release, and to determine the slip function of the 3-sec nucleation process. Relative location of the onset of the large energy release with respect to the initial hypocenter indicates its source was between 1 and 4 km north of the hypocenter and delayed by approximately 2.5 sec. Three-station array analysis of the P wave shows that the large amplitude onset arrives with a faster apparent velocity compared to the first arrivals, indicating that the large amplitude source was several kilometers deeper than the initial onset. An ML 2.8 foreshock, located close to the hypocenter, was used as an empirical Green's function to correct for path and site effects from the first 3 sec of the mainshock seismogram. The resultant deconvolution produced a slip function that showed two subevents preceding the main energy release, an MW4.4 followed by an MW 5.6. These subevents do not appear anomalous in comparison to simple moderate-sized earthquakes, suggesting that they were normal events which just triggered or grew into a much larger earthquake. If small and moderate-sized earthquakes commonly “detonate” much larger events, this implies that the dynamic stresses during earthquake rupture are at least as important as long-term static stresses in causing earthquakes, and the prospects of reliable earthquake prediction from premonitory phenomena are not improved.

  15. 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.

  16. Modeling fast and slow earthquakes at various scales

    PubMed Central

    IDE, Satoshi

    2014-01-01

    Earthquake sources represent dynamic rupture within rocky materials at depth and often can be modeled as propagating shear slip controlled by friction laws. These laws provide boundary conditions on fault planes embedded in elastic media. Recent developments in observation networks, laboratory experiments, and methods of data analysis have expanded our knowledge of the physics of earthquakes. Newly discovered slow earthquakes are qualitatively different phenomena from ordinary fast earthquakes and provide independent information on slow deformation at depth. Many numerical simulations have been carried out to model both fast and slow earthquakes, but problems remain, especially with scaling laws. Some mechanisms are required to explain the power-law nature of earthquake rupture and the lack of characteristic length. Conceptual models that include a hierarchical structure over a wide range of scales would be helpful for characterizing diverse behavior in different seismic regions and for improving probabilistic forecasts of earthquakes. PMID:25311138

  17. Modeling fast and slow earthquakes at various scales.

    PubMed

    Ide, Satoshi

    2014-01-01

    Earthquake sources represent dynamic rupture within rocky materials at depth and often can be modeled as propagating shear slip controlled by friction laws. These laws provide boundary conditions on fault planes embedded in elastic media. Recent developments in observation networks, laboratory experiments, and methods of data analysis have expanded our knowledge of the physics of earthquakes. Newly discovered slow earthquakes are qualitatively different phenomena from ordinary fast earthquakes and provide independent information on slow deformation at depth. Many numerical simulations have been carried out to model both fast and slow earthquakes, but problems remain, especially with scaling laws. Some mechanisms are required to explain the power-law nature of earthquake rupture and the lack of characteristic length. Conceptual models that include a hierarchical structure over a wide range of scales would be helpful for characterizing diverse behavior in different seismic regions and for improving probabilistic forecasts of earthquakes.

  18. Ultrafast Phenomena XIV

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takayoshi; Okada, Tadashi; Kobayashi, Tetsuro; Nelson, Keith A.; de Silvestri, Sandro

    Ultrafast Phenomena XIV presents the latest advances in ultrafast science, including ultrafast laser and measurement technology as well as studies of ultrafast phenomena. Pico-, femto-, and atosecond processes relevant in physics, chemistry, biology, and engineering are presented. Ultrafast technology is now having a profound impact within a wide range of applications, among them imaging, material diagnostics, and transformation and high-speed optoelectronics . This book summarizes results presented at the 14th Ultrafast Phenomena Conference and reviews the state of the art in this important and rapidly advancing field.

  19. New ideas about the physics of earthquakes

    NASA Astrophysics Data System (ADS)

    Rundle, John B.; Klein, William

    1995-07-01

    It may be no exaggeration to claim that this most recent quaddrenium has seen more controversy and thus more progress in understanding the physics of earthquakes than any in recent memory. The most interesting development has clearly been the emergence of a large community of condensed matter physicists around the world who have begun working on the problem of earthquake physics. These scientists bring to the study of earthquakes an entirely new viewpoint, grounded in the physics of nucleation and critical phenomena in thermal, magnetic, and other systems. Moreover, a surprising technology transfer from geophysics to other fields has been made possible by the realization that models originally proposed to explain self-organization in earthquakes can also be used to explain similar processes in problems as disparate as brain dynamics in neurobiology (Hopfield, 1994), and charge density waves in solids (Brown and Gruner, 1994). An entirely new sub-discipline is emerging that is focused around the development and analysis of large scale numerical simulations of the dynamics of faults. At the same time, intriguing new laboratory and field data, together with insightful physical reasoning, has led to significant advances in our understanding of earthquake source physics. As a consequence, we can anticipate substantial improvement in our ability to understand the nature of earthquake occurrence. Moreover, while much research in the area of earthquake physics is fundamental in character, the results have many potential applications (Cornell et al., 1993) in the areas of earthquake risk and hazard analysis, and seismic zonation.

  20. Determination of the fault plane and rupture size of the 2013 Santa Cruz earthquake, Bolivia, 5.2 Mw, by relative location of the aftershocks

    NASA Astrophysics Data System (ADS)

    Rivadeneyra-Vera, C.; Assumpção, M.; Minaya, E.; Aliaga, P.; Avila, G.

    2016-11-01

    The Central Andes of southern Bolivia is a highly seismic region with many active faults, that could generate earthquakes up to 8.9 Mw. In 2013, an earthquake of 5.2 Mw occurred in Santa Cruz de la Sierra, in the sub-Andean belt, close to the Mandeyapecua fault, one of the most important reverse faults in Bolivia. Five larger aftershocks were reported by the International Seismological Centre (ISC) and 33 smaller aftershocks were recorded by the San Calixto Observatory (OSC) in the two months after the mainshock. Distances between epicenters of the events were up to 36 km, which is larger than expected for an earthquake of this magnitude. Using data from South American regional stations and the relative location technique with Rayleigh waves, the epicenters of the five larger aftershocks of the Santa Cruz series were determined in relation to the mainshock. This method enabled to achieve epicentral locations with uncertainties smaller than 1 km. Additionally, using data of three Bolivian stations (MOC, SIV and LPAZ) eight smaller aftershocks, recorded by the OSC, were relocated through correlation of P and S waves. The results show a NNW-SSE trend of epicenters and suggest an E dipping plane. The maximum distance between the aftershocks is 14 km, which is not consistent with the expected subsurface rupture length, in accordance with the magnitude of the mainshock. The events are located away from the Mandeyapecua fault and show an opposite dip, demonstrating that these events were generated by another fault in the area, that had not been well studied yet.

  1. Nonlinear waves in earth crust faults: application to regular and slow earthquakes

    NASA Astrophysics Data System (ADS)

    Gershenzon, Naum; Bambakidis, Gust

    2015-04-01

    The genesis, development and cessation of regular earthquakes continue to be major problems of modern geophysics. How are earthquakes initiated? What factors determine the rapture velocity, slip velocity, rise time and geometry of rupture? How do accumulated stresses relax after the main shock? These and other questions still need to be answered. In addition, slow slip events have attracted much attention as an additional source for monitoring fault dynamics. Recently discovered phenomena such as deep non-volcanic tremor (NVT), low frequency earthquakes (LFE), very low frequency earthquakes (VLF), and episodic tremor and slip (ETS) have enhanced and complemented our knowledge of fault dynamic. At the same time, these phenomena give rise to new questions about their genesis, properties and relation to regular earthquakes. We have developed a model of macroscopic dry friction which efficiently describes laboratory frictional experiments [1], basic properties of regular earthquakes including post-seismic stress relaxation [3], the occurrence of ambient and triggered NVT [4], and ETS events [5, 6]. Here we will discuss the basics of the model and its geophysical applications. References [1] Gershenzon N.I. & G. Bambakidis (2013) Tribology International, 61, 11-18, http://dx.doi.org/10.1016/j.triboint.2012.11.025 [2] Gershenzon, N.I., G. Bambakidis and T. Skinner (2014) Lubricants 2014, 2, 1-x manuscripts; doi:10.3390/lubricants20x000x; arXiv:1411.1030v2 [3] Gershenzon N.I., Bykov V. G. and Bambakidis G., (2009) Physical Review E 79, 056601 [4] Gershenzon, N. I, G. Bambakidis, (2014a), Bull. Seismol. Soc. Am., 104, 4, doi: 10.1785/0120130234 [5] Gershenzon, N. I.,G. Bambakidis, E. Hauser, A. Ghosh, and K. C. Creager (2011), Geophys. Res. Lett., 38, L01309, doi:10.1029/2010GL045225. [6] Gershenzon, N.I. and G. Bambakidis (2014) Bull. Seismol. Soc. Am., (in press); arXiv:1411.1020

  2. ELECTRICAL PHENOMENA IN NERVE

    PubMed Central

    Shanes, Abraham M.

    1949-01-01

    The action of a number of agents, which may be classified as "stabilizers" and "unstabilizers" on the electrical oscillations and after-potentials in the squid giant axon has been examined. The effects on the spike, "positive overshoot," and "potassium potential" were also observed, but where possible concentrations were employed which left these phenomena unaltered. Veratrine augmented the oscillations and the negative after-potential, particularly with repetitive stimulation. Yohimbine caused a small long lasting positive after-potential and depressed the oscillations, effects also enhanced with repetitive activity. Cocaine and procaine suppressed the oscillations and the negative after-potential but DDT was completely inert. An elevation in the medium calcium depressed the oscillations and the naturally occurring negative after-potential; negative after-potentials induced with veratrine were increased by calcium. A decrease in the potassium augmented the oscillations and the negative after-potential. A hypothesis is presented in which these effects are interpreted in terms of potassium concentration at the fiber surface as regulated by a labile permeability and metabolism. This is discussed in relation to the available evidence for these factors. It is a pleasure to acknowledge the author's indebtedness to Dr. D. E. S. Brown, Director, and to his staff at the Bermuda Biological Station for Research for the cooperation and special facilities provided during the initiation of this work. Dr. T. Baylor of Princeton University very kindly provided the camera and film used in Bermuda. PMID:18139008

  3. GPS Technologies as a Tool to Detect the Pre-Earthquake Signals Associated with Strong Earthquakes

    NASA Astrophysics Data System (ADS)

    Pulinets, S. A.; Krankowski, A.; Hernandez-Pajares, M.; Liu, J. Y. G.; Hattori, K.; Davidenko, D.; Ouzounov, D.

    2015-12-01

    The existence of ionospheric anomalies before earthquakes is now widely accepted. These phenomena started to be considered by GPS community to mitigate the GPS signal degradation over the territories of the earthquake preparation. The question is still open if they could be useful for seismology and for short-term earthquake forecast. More than decade of intensive studies proved that ionospheric anomalies registered before earthquakes are initiated by processes in the boundary layer of atmosphere over earthquake preparation zone and are induced in the ionosphere by electromagnetic coupling through the Global Electric Circuit. Multiparameter approach based on the Lithosphere-Atmosphere-Ionosphere Coupling model demonstrated that earthquake forecast is possible only if we consider the final stage of earthquake preparation in the multidimensional space where every dimension is one from many precursors in ensemble, and they are synergistically connected. We demonstrate approaches developed in different countries (Russia, Taiwan, Japan, Spain, and Poland) within the framework of the ISSI and ESA projects) to identify the ionospheric precursors. They are also useful to determine the all three parameters necessary for the earthquake forecast: impending earthquake epicenter position, expectation time and magnitude. These parameters are calculated using different technologies of GPS signal processing: time series, correlation, spectral analysis, ionospheric tomography, wave propagation, etc. Obtained results from different teams demonstrate the high level of statistical significance and physical justification what gives us reason to suggest these methodologies for practical validation.

  4. Earthquake and Tsunami booklet based on two Indonesia earthquakes

    NASA Astrophysics Data System (ADS)

    Hayashi, Y.; Aci, M.

    2014-12-01

    Many destructive earthquakes occurred during the last decade in Indonesia. These experiences are very important precepts for the world people who live in earthquake and tsunami countries. We are collecting the testimonies of tsunami survivors to clarify successful evacuation process and to make clear the characteristic physical behaviors of tsunami near coast. We research 2 tsunami events, 2004 Indian Ocean tsunami and 2010 Mentawai slow earthquake tsunami. Many video and photographs were taken by people at some places in 2004 Indian ocean tsunami disaster; nevertheless these were few restricted points. We didn't know the tsunami behavior in another place. In this study, we tried to collect extensive information about tsunami behavior not only in many places but also wide time range after the strong shake. In Mentawai case, the earthquake occurred in night, so there are no impressive photos. To collect detail information about evacuation process from tsunamis, we contrived the interview method. This method contains making pictures of tsunami experience from the scene of victims' stories. In 2004 Aceh case, all survivors didn't know tsunami phenomena. Because there were no big earthquakes with tsunami for one hundred years in Sumatra region, public people had no knowledge about tsunami. This situation was highly improved in 2010 Mentawai case. TV programs and NGO or governmental public education programs about tsunami evacuation are widespread in Indonesia. Many people know about fundamental knowledge of earthquake and tsunami disasters. We made drill book based on victim's stories and painted impressive scene of 2 events. We used the drill book in disaster education event in school committee of west Java. About 80 % students and teachers evaluated that the contents of the drill book are useful for correct understanding.

  5. Satellite Infrared Radiation Measurements Prior to the Major Earthquakes

    NASA Technical Reports Server (NTRS)

    Ouzounov, Dimitar; Pulintes, S.; Bryant, N.; Taylor, Patrick; Freund, F.

    2005-01-01

    This work describes our search for a relationship between tectonic stresses and increases in mid-infrared (IR) flux as part of a possible ensemble of electromagnetic (EM) phenomena that may be related to earthquake activity. We present and &scuss observed variations in thermal transients and radiation fields prior to the earthquakes of Jan 22, 2003 Colima (M6.7) Mexico, Sept. 28 .2004 near Parkfield (M6.0) in California and Northern Sumatra (M8.5) Dec. 26,2004. Previous analysis of earthquake events has indicated the presence of an IR anomaly, where temperatures increased or did not return to its usual nighttime value. Our procedures analyze nighttime satellite data that records the general condtion of the ground after sunset. We have found from the MODIS instrument data that five days before the Colima earthquake the IR land surface nighttime temperature rose up to +4 degrees C in a 100 km radius around the epicenter. The IR transient field recorded by MODIS in the vicinity of Parkfield, also with a cloud free environment, was around +1 degree C and is significantly smaller than the IR anomaly around the Colima epicenter. Ground surface temperatures near the Parkfield epicenter four days prior to the earthquake show steady increase. However, on the night preceding the quake, a significant drop in relative humidity was indicated, process similar to those register prior to the Colima event. Recent analyses of continuous ongoing long- wavelength Earth radiation (OLR) indicate significant and anomalous variability prior to some earthquakes. The cause of these anomalies is not well understood but could be the result of a triggering by an interaction between the lithosphere-hydrosphere and atmospheric related to changes in the near surface electrical field and/or gas composition prior to the earthquake. The OLR anomaly usually covers large areas surrounding the main epicenter. We have found strong anomalies signal (two sigma) along the epicentral area signals on Dec 21

  6. Connecting slow earthquakes to huge earthquakes.

    PubMed

    Obara, Kazushige; Kato, Aitaro

    2016-07-15

    Slow earthquakes are characterized by a wide spectrum of fault slip behaviors and seismic radiation patterns that differ from those of traditional earthquakes. However, slow earthquakes and huge megathrust earthquakes can have common slip mechanisms and are located in neighboring regions of the seismogenic zone. The frequent occurrence of slow earthquakes may help to reveal the physics underlying megathrust events as useful analogs. Slow earthquakes may function as stress meters because of their high sensitivity to stress changes in the seismogenic zone. Episodic stress transfer to megathrust source faults leads to an increased probability of triggering huge earthquakes if the adjacent locked region is critically loaded. Careful and precise monitoring of slow earthquakes may provide new information on the likelihood of impending huge earthquakes. Copyright © 2016, American Association for the Advancement of Science.

  7. Attempt at correlating Italian long lineaments from LANDSAT-1 satellite images with some geological phenomena. Possible use in geothermal energy research

    NASA Technical Reports Server (NTRS)

    Barbier, E.; Fanelli, M.

    1975-01-01

    By utilizing the images from the LANDSAT-1, in the spectral band 0.8-1.1 microns (near infrared), a photomosaic was obtained of Italian territory. From this mosaic the field of long lineaments was drawn, corresponding to fractures of the earth crust more than 100 km long. The relationship between lineaments, hot springs, volcanic areas, and earthquake epicenters is verified. There is a clear connection between long lineaments and hot springs: 78% of the springs are located on one or more lineaments, and the existence of hot lineaments was observed. A slightly weaker, but still significant, connection exists between the Pliocene-Quaternary volcanic areas and long lineaments. The relationship between earthquakes and long lineaments can only be verified in some cases. The lineaments which can be related to earthquakes have little or no connection with the other phenomena.

  8. A Connection between Transport Phenomena and Thermodynamics

    ERIC Educational Resources Information Center

    Swaney, Ross; Bird, R. Byron

    2017-01-01

    Although students take courses in transport phenomena and thermodynamics, they probably do not ask whether these two subjects are related. Here we give an answer to that question. Specifically we give relationships between the equations of change for total energy, internal energy, and entropy of transport phenomena and key equations of equilibrium…

  9. Road Damage Following Earthquake

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Ground shaking triggered liquefaction in a subsurface layer of water-saturated sand, producing differential lateral and vertical movement in a overlying carapace of unliquified sand and slit, which moved from right to left towards the Pajaro River. This mode of ground failure, termed lateral spreading, is a principal cause of liquefaction-related earthquake damage caused by the Oct. 17, 1989, Loma Prieta earthquake. Sand and soil grains have faces that can cause friction as they roll and slide against each other, or even cause sticking and form small voids between grains. This complex behavior can cause soil to behave like a liquid under certain conditions such as earthquakes or when powders are handled in industrial processes. Mechanics of Granular Materials (MGM) experiments aboard the Space Shuttle use the microgravity of space to simulate this behavior under conditons that carnot be achieved in laboratory tests on Earth. MGM is shedding light on the behavior of fine-grain materials under low effective stresses. Applications include earthquake engineering, granular flow technologies (such as powder feed systems for pharmaceuticals and fertilizers), and terrestrial and planetary geology. Nine MGM specimens have flown on two Space Shuttle flights. Another three are scheduled to fly on STS-107. The principal investigator is Stein Sture of the University of Colorado at Boulder. Credit: S.D. Ellen, U.S. Geological Survey

  10. Observations and recommendations regarding landslide hazards related to the January 13, 2001 M-7.6 El Salvador earthquake

    Jibson, Randall W.; Crone, Anthony J.

    2001-01-01

    The January 13, 2001 earthquake (M-7.6) off the coast of El Salvador triggered widespread damaging landslides in many parts of the El Salvador. In the aftermath of the earthquake, the Salvadoran government requested technical assistance through the U.S. Agency for International Development (USAID); USAID, in turn, requested help from technical experts in landslide hazards from the U.S. Geological Survey. In response to that request, we arrived in El Salvador on January 31, 2001 and worked with USAID personnel and Salvadoran agency counterparts in visiting landslide sites and evaluating present and potential hazards. A preliminary, unofficial report was prepared at the end of our trip (February 9) to provide immediate information and assistance to interested agencies and parties. The current report is an updated and somewhat expanded version of that unofficial report. Because of the brief nature of this report, conclusions and recommendations contained herein should be considered tentative and may be revised in the future.

  11. Defeating Earthquakes

    NASA Astrophysics Data System (ADS)

    Stein, R. S.

    2012-12-01

    The 2004 M=9.2 Sumatra earthquake claimed what seemed an unfathomable 228,000 lives, although because of its size, we could at least assure ourselves that it was an extremely rare event. But in the short space of 8 years, the Sumatra quake no longer looks like an anomaly, and it is no longer even the worst disaster of the Century: 80,000 deaths in the 2005 M=7.6 Pakistan quake; 88,000 deaths in the 2008 M=7.9 Wenchuan, China quake; 316,000 deaths in the M=7.0 Haiti, quake. In each case, poor design and construction were unable to withstand the ferocity of the shaken earth. And this was compounded by inadequate rescue, medical care, and shelter. How could the toll continue to mount despite the advances in our understanding of quake risk? The world's population is flowing into megacities, and many of these migration magnets lie astride the plate boundaries. Caught between these opposing demographic and seismic forces are 50 cities of at least 3 million people threatened by large earthquakes, the targets of chance. What we know for certain is that no one will take protective measures unless they are convinced they are at risk. Furnishing that knowledge is the animating principle of the Global Earthquake Model, launched in 2009. At the very least, everyone should be able to learn what his or her risk is. At the very least, our community owes the world an estimate of that risk. So, first and foremost, GEM seeks to raise quake risk awareness. We have no illusions that maps or models raise awareness; instead, earthquakes do. But when a quake strikes, people need a credible place to go to answer the question, how vulnerable am I, and what can I do about it? The Global Earthquake Model is being built with GEM's new open source engine, OpenQuake. GEM is also assembling the global data sets without which we will never improve our understanding of where, how large, and how frequently earthquakes will strike, what impacts they will have, and how those impacts can be lessened by

  12. Issues on the Japanese Earthquake Hazard Evaluation

    NASA Astrophysics Data System (ADS)

    Hashimoto, M.; Fukushima, Y.; Sagiya, T.

    2013-12-01

    The 2011 Great East Japan Earthquake forced the policy of counter-measurements to earthquake disasters, including earthquake hazard evaluations, to be changed in Japan. Before the March 11, Japanese earthquake hazard evaluation was based on the history of earthquakes that repeatedly occurs and the characteristic earthquake model. The source region of an earthquake was identified and its occurrence history was revealed. Then the conditional probability was estimated using the renewal model. However, the Japanese authorities changed the policy after the megathrust earthquake in 2011 such that the largest earthquake in a specific seismic zone should be assumed on the basis of available scientific knowledge. According to this policy, three important reports were issued during these two years. First, the Central Disaster Management Council issued a new estimate of damages by a hypothetical Mw9 earthquake along the Nankai trough during 2011 and 2012. The model predicts a 34 m high tsunami on the southern Shikoku coast and intensity 6 or higher on the JMA scale in most area of Southwest Japan as the maximum. Next, the Earthquake Research Council revised the long-term earthquake hazard evaluation of earthquakes along the Nankai trough in May 2013, which discarded the characteristic earthquake model and put much emphasis on the diversity of earthquakes. The so-called 'Tokai' earthquake was negated in this evaluation. Finally, another report by the CDMC concluded that, with the current knowledge, it is hard to predict the occurrence of large earthquakes along the Nankai trough using the present techniques, based on the diversity of earthquake phenomena. These reports created sensations throughout the country and local governments are struggling to prepare counter-measurements. These reports commented on large uncertainty in their evaluation near their ends, but are these messages transmitted properly to the public? Earthquake scientists, including authors, are involved in

  13. Earthquake clouds and physical mechanism of their formation.

    NASA Astrophysics Data System (ADS)

    Doda, L.; Pulinets, S.

    2006-12-01

    The Lithosphere-Atmosphere-Ionosphere (LAI) coupling model created recently permitted to explain some unknown phenomena observed around the time of strong earthquakes. One of them is formation of special shape clouds, usually presented as the thin linear structures. It was discovered that these clouds are associated with the active tectonic faults or with the tectonic plate borders. They repeat the fault shape but usually are turned in relation to the fault position. Their formation is explained by the anomalous vertical electric field generated in the vicinity of active tectonic structure due to air ionization produced by the radon increased emanation. The new formed ions through the hydration process do not recombine and growth with time due to increased water molecules attachment to the ion. Simultaneously they move up driven by the anomalous electric field and drift in the crossed ExB fields. At the higher altitudes the large ion clusters become the centers of condensation and the cloud formation. Examples for the recent major earthquakes (Sumatra 2004, Kashmir 2005, Java 2006) are presented. The size and the angle of the cloud rotation in relation to the fault position permit to estimate the magnitude of the impending earthquake.

  14. Earthquake Damping Device for Steel Frame

    NASA Astrophysics Data System (ADS)

    Zamri Ramli, Mohd; Delfy, Dezoura; Adnan, Azlan; Torman, Zaida

    2018-04-01

    Structures such as buildings, bridges and towers are prone to collapse when natural phenomena like earthquake occurred. Therefore, many design codes are reviewed and new technologies are introduced to resist earthquake energy especially on building to avoid collapse. The tuned mass damper is one of the earthquake reduction products introduced on structures to minimise the earthquake effect. This study aims to analyse the effectiveness of tuned mass damper by experimental works and finite element modelling. The comparisons are made between these two models under harmonic excitation. Based on the result, it is proven that installing tuned mass damper will reduce the dynamic response of the frame but only in several input frequencies. At the highest input frequency applied, the tuned mass damper failed to reduce the responses. In conclusion, in order to use a proper design of damper, detailed analysis must be carried out to have sufficient design based on the location of the structures with specific ground accelerations.

  15. Understanding earthquake from the granular physics point of view — Causes of earthquake, earthquake precursors and predictions

    NASA Astrophysics Data System (ADS)

    Lu, Kunquan; Hou, Meiying; Jiang, Zehui; Wang, Qiang; Sun, Gang; Liu, Jixing

    2018-03-01

    We treat the earth crust and mantle as large scale discrete matters based on the principles of granular physics and existing experimental observations. Main outcomes are: A granular model of the structure and movement of the earth crust and mantle is established. The formation mechanism of the tectonic forces, which causes the earthquake, and a model of propagation for precursory information are proposed. Properties of the seismic precursory information and its relevance with the earthquake occurrence are illustrated, and principle of ways to detect the effective seismic precursor is elaborated. The mechanism of deep-focus earthquake is also explained by the jamming-unjamming transition of the granular flow. Some earthquake phenomena which were previously difficult to understand are explained, and the predictability of the earthquake is discussed. Due to the discrete nature of the earth crust and mantle, the continuum theory no longer applies during the quasi-static seismological process. In this paper, based on the principles of granular physics, we study the causes of earthquakes, earthquake precursors and predictions, and a new understanding, different from the traditional seismological viewpoint, is obtained.

  16. Some statistical features of the seismic activity related to the recent M8.2 and M7.1 earthquakes in Mexico

    NASA Astrophysics Data System (ADS)

    Guzman, L.; Baeza-Blancas, E.; Reyes, I.; Angulo Brown, F.; Rudolf Navarro, A.

    2017-12-01

    By studying the magnitude earthquake catalogs, previous studies have reported evidence that some changes in the spatial and temporal organization of earthquake activity is observedbefore and after of a main-shock. These previous studies have used different approach methods for detecting clustering behavior and distance-events density in order topoint out the asymmetric behavior of before shocks and aftershocks. Here, we present a statistical analysis of the seismic activity related to the M8.2 and M7.1 earthquakes occurredon Sept. 7th and Sept. 19th, respectively. First, we calculated the interevent time and distance for the period Sept. 7th 2016 until Oct. 20th 2017 for each seismic region ( a radius of 150 km centeredat coordinates of the M8.1 and M7.1). Next, we calculated the "velocity" of the walker as the ratio between the interevent distance and interevent time, and similarly, we also constructed the"acceleration". A slider pointer is considered to estimate some statistical features within time windows of size τ for the velocity and acceleration sequences before and after the main shocks. Specifically, we applied the fractal dimension method to detect changes in the correlation (persistence) behavior of events in the period before the main events.Our preliminary results pointed out that the fractal dimension associated to the velocity and acceleration sequences exhibits changes in the persistence behavior before the mainshock, while thescaling dimension values after the main events resemble a more uncorrelated behavior. Moreover, the relationship between the standard deviation of the velocity and the local mean velocity valuefor a given time window-size τ is described by an exponent close to 1.5, and the cumulative distribution of velocity and acceleration are well described by power law functions after the crash and stretched-exponential-like distribution before the main shock. On the other hand, we present an analysis of patterns of seismicquiescence

  17. Symposium Entitled: Particle Lung Interactions: ’Overload’ Related Phenomena. A Journal of Aerosol Medicine - Deposition, Clearance, and Effects in the Lung. Volume 3, Supplement 1

    DTIC Science & Technology

    1991-04-01

    week and two years (subchronic GMRL studies versus chronic ITRI and Fh-ITA studies ); exposure concentrations were changed by a factor of 40 (Fh-ITA...a forum for the publication of studies involving inhalation of particles and gases in the respiratory tract, covering the use of aerosols as tools to... study basic physiologic phenomena, their use as selective delivery systems for medication, and the toxic effects of inhaled agents. JOURNAL OF AEROSOL

  18. Detection of co-seismic earthquake gravity field signals using GRACE-like mission simulations

    NASA Astrophysics Data System (ADS)

    Sharifi, Mohammad Ali; Shahamat, Abolfazl

    2017-05-01

    After launching the GRACE satellite mission in 2002, the earth's gravity field and its temporal variations are measured with a closer inspection. Although these variations are mainly because of the mass transfer of land water storage, they can also happen due to mass movements related to some natural phenomena including earthquakes, volcanic eruptions, melting of polar ice caps and glacial isostatic adjustment. Therefore this paper shows which parameters of an earthquake are more sensitive to GRACE-Like satellite missions. For this purpose, the parameters of the Maule earthquake that occurred in recent years and Alaska earthquake that occurred in 1964 have been chosen. Then we changed their several parameters to serve our purpose. The GRACE-Like sensitivity is observed by using the simulation of the earthquakes along with gravity changes they caused, as well as using dislocation theory under a half space earth. This observation affects the various faulting parameters which include fault length, width, depth and average slip. These changes were therefore evaluated and the result shows that the GRACE satellite missions tend to be more sensitive to Width among the Length and Width, the other parameter is Dip variations than other parameters. This article can be useful to the upcoming scenario designers and seismologists in their quest to study fault parameters.

  19. The EM Earthquake Precursor

    NASA Astrophysics Data System (ADS)

    Jones, K. B., II; Saxton, P. T.

    2013-12-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After the 1989 Loma Prieta Earthquake, American earthquake investigators predetermined magnetometer use and a minimum earthquake magnitude necessary for EM detection. This action was set in motion, due to the extensive damage incurred and public outrage concerning earthquake forecasting; however, the magnetometers employed, grounded or buried, are completely subject to static and electric fields and have yet to correlate to an identifiable precursor. Secondly, there is neither a networked array for finding any epicentral locations, nor have there been any attempts to find even one. This methodology needs dismissal, because it is overly complicated, subject to continuous change, and provides no response time. As for the minimum magnitude threshold, which was set at M5, this is simply higher than what modern technological advances have gained. Detection can now be achieved at approximately M1, which greatly improves forecasting chances. A propagating precursor has now been detected in both the field and laboratory. Field antenna testing conducted outside the NE Texas town of Timpson in February, 2013, detected three strong EM sources along with numerous weaker signals. The antenna had mobility, and observations were noted for recurrence, duration, and frequency response. Next, two

  20. Journal of Transportation and Statistics : special issue on the Northridge earthquake

    DOT National Transportation Integrated Search

    1998-09-01

    This is special issue on the Northridge Earthquake. Contents: Impacts of the Northridge Earthquake on Transit and Highway Use by Genevieve Giuliano; Transport Related Impacts on the Northridge Earthquake by Peter Gordon; Goods Movement After the Nort...

  1. Ion exchange phenomena

    SciT

    Bourg, I.C.; Sposito, G.

    Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculationmore » (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).« less

  2. Surface faulting along the inland Itozawa normal fault (eastern Japan) and relation to the 2011 Tohoku-oki megathrust earthquake

    NASA Astrophysics Data System (ADS)

    Ferry, Matthieu; Tsutsumi, Hiroyuki; Meghraoui, Mustapha; Toda, Shinji

    2013-04-01

    The 11 March 2011 Mw 9 Tohoku-oki earthquake ruptured ~500 km length of the Japan Trench along the coast of eastern Japan and significantly impacted the stress regime within the crust. The resulting change in seismicity over the Japan mainland was exhibited by the 11 April 2011 Mw 6.6 Iwaki earthquake that ruptured the Itozawa and Yunodake faults. Trending NNW and NW, respectively, these 70-80° W-dipping faults bound the Iwaki basin of Neogene age and have been reactivated simultaneously both along 15-km-long sections. Here, we present initial results from a paleoseismic excavation performed across the Itozawa fault within the Tsunagi Valley at the northern third of the observed surface rupture. At the Tsunagi site, the rupture affects a rice paddy, which provides an ideally horizontal initial state to collect detailed and accurate measurements. The surface break is composed of a continuous 30-to-40-cm-wide purely extensional crack that separates the uplifted block from a gently dipping 1-to-2-m-wide strip affected by right-stepping en-echelon cracks and locally bounded by a ~0.1-m-high reverse scarplet. Total station across-fault topographic profiles indicate the pre-earthquake ground surface was vertically deformed by ~0.6 m while direct field examinations reveal that well-defined rice paddy limits have been left-laterally offset by ~0.1 m. The 12-m-long, 3.5-m-deep trench exposes the 30-to-40-cm-thick cultivated soil overlaying a 1-m-thick red to yellow silt unit, a 2-m-thick alluvial gravel unit and a basal 0.1-1-m-thick organic-rich silt unit. Deformation associated to the 2011 rupture illustrates down-dip movement along a near-vertical fault with a well-expressed bending moment at the surface and generalized warping. On the north wall, the intermediate gravel unit displays a deformation pattern similar to granular flow with only minor discrete faulting and no splay to be continuously followed from the main fault to the surface. On the south wall, warping

  3. Surface faulting along the inland Itozawa normal fault (eastern Japan) and relation to the 2011 Tohoku-oki megathrust earthquake

    NASA Astrophysics Data System (ADS)

    Ferry, M.; Tsutsumi, H.; Meghraoui, M.; Toda, S.

    2012-12-01

    The 11 March 2011 Mw 9 Tohoku-oki earthquake ruptured ~500 km length of the Japan Trench along the coast of eastern Japan and significantly impacted the stress regime within the crust. The resulting change in seismicity over the Japan mainland was exhibited by the 11 April 2011 Mw 6.6 Iwaki earthquake that ruptured the Itozawa and Yunodake faults. Trending NNW and NW, respectively, these 70-80° W-dipping faults bound the Iwaki basin of Neogene age and have been reactivated simultaneously both along 15-km-long sections. Here, we present initial results from a paleoseismic excavation performed across the Itozawa fault within the Tsunagi Valley at the northern third of the observed surface rupture. At the Tsunagi site, the rupture affects a rice paddy, which provides an ideally horizontal initial state to collect detailed and accurate measurements. The surface break is composed of a continuous 30-to-40-cm-wide purely extensional crack that separates the uplifted block from a gently dipping 1-to-2-m-wide strip affected by right-stepping en-echelon cracks and locally bounded by a ~0.1-m-high reverse scarplet. Total station across-fault topographic profiles indicate the pre-earthquake ground surface was vertically deformed by ~0.6 m while direct field examinations reveal that well-defined rice paddy limits have been left-laterally offset by ~0.1 m. The 12-m-long, 3.5-m-deep trench exposes the 30-to-40-cm-thick cultivated soil overlaying a 1-m-thick red to yellow silt unit, a 2-m-thick alluvial gravel unit and a basal 0.1-1-m-thick organic-rich silt unit. Deformation associated to the 2011 rupture illustrates down-dip movement along a near-vertical fault with a well-expressed bending moment at the surface and generalized warping. On the north wall, the intermediate gravel unit displays a deformation pattern similar to granular flow with only minor discrete faulting and no splay to be continuously followed from the main fault to the surface. On the south wall, warping

  4. Self-esteem and hope mediate the relations between social support and post-traumatic stress disorder and growth in adolescents following the Ya'an earthquake.

    PubMed

    Zhou, Xiao; Wu, Xinchun; Zhen, Rui

    2018-01-01

    Although posttraumatic stress disorders (PTSD) and posttraumatic growth (PTG) can co-exist, and several theories suggest that social support, self-esteem, and hope can predict both PTSD and PTG, no study to date has examined the combined role of social support, self-esteem, and hope in PTSD and PTG. The present study aimed to simultaneously examine the mediating roles of self-esteem and hope in the relations between social support and PTSD, and between social support and PTG. This study included 397 adolescents living in Lushan County, China, who were affected by the Ya'an earthquake. The participants completed the self-report questionnaires at two and a half years after the earthquake. Structural equation models were built to examine the roles of social support, self-esteem, and hope in PTSD and PTG. Social support directly and negatively predicted PTSD and positively predicted PTG. Moreover, social support negatively predicted PTSD via self-esteem, and positively predicted PTG via hope. In addition, social support positively predicted PTG through multiple mediating paths from self-esteem to hope. PTSD and PTG had different predictive paths. Specifically, social support reduced PTSD through enhanced self-esteem and promoted PTG through hope, or through the path from self-esteem to hope.

  5. Earthquake nucleation on faults with rate-and state-dependent strength

    Dieterich, J.H.

    1992-01-01

    Dieterich, J.H., 1992. Earthquake nucleation on faults with rate- and state-dependent strength. In: T. Mikumo, K. Aki, M. Ohnaka, L.J. Ruff and P.K.P. Spudich (Editors), Earthquake Source Physics and Earthquake Precursors. Tectonophysics, 211: 115-134. Faults with rate- and state-dependent constitutive properties reproduce a range of observed fault slip phenomena including spontaneous nucleation of slip instabilities at stresses above some critical stress level and recovery of strength following slip instability. Calculations with a plane-strain fault model with spatially varying properties demonstrate that accelerating slip precedes instability and becomes localized to a fault patch. The dimensions of the fault patch follow scaling relations for the minimum critical length for unstable fault slip. The critical length is a function of normal stress, loading conditions and constitutive parameters which include Dc, the characteristic slip distance. If slip starts on a patch that exceeds the critical size, the length of the rapidly accelerating zone tends to shrink to the characteristic size as the time of instability approaches. Solutions have been obtained for a uniform, fixed-patch model that are in good agreement with results from the plane-strain model. Over a wide range of conditions, above the steady-state stress, the logarithm of the time to instability linearly decreases as the initial stress increases. Because nucleation patch length and premonitory displacement are proportional to Dc, the moment of premonitory slip scales by D3c. The scaling of Dc is currently an open question. Unless Dc for earthquake faults is significantly greater than that observed on laboratory faults, premonitory strain arising from the nucleation process for earthquakes may by too small to detect using current observation methods. Excluding the possibility that Dc in the nucleation zone controls the magnitude of the subsequent earthquake, then the source dimensions of the smallest

  6. Geochemical challenge to earthquake prediction.

    PubMed Central

    Wakita, H

    1996-01-01

    The current status of geochemical and groundwater observations for earthquake prediction in Japan is described. The development of the observations is discussed in relation to the progress of the earthquake prediction program in Japan. Three major findings obtained from our recent studies are outlined. (i) Long-term radon observation data over 18 years at the SKE (Suikoen) well indicate that the anomalous radon change before the 1978 Izu-Oshima-kinkai earthquake can with high probability be attributed to precursory changes. (ii) It is proposed that certain sensitive wells exist which have the potential to detect precursory changes. (iii) The appearance and nonappearance of coseismic radon drops at the KSM (Kashima) well reflect changes in the regional stress state of an observation area. In addition, some preliminary results of chemical changes of groundwater prior to the 1995 Kobe (Hyogo-ken nanbu) earthquake are presented. PMID:11607665

  7. "Storms of crustal stress" and AE earthquake precursors

    NASA Astrophysics Data System (ADS)

    Gregori, G. P.; Poscolieri, M.; Paparo, G.; de Simone, S.; Rafanelli, C.; Ventrice, G.

    2010-02-01

    "storm", started in 2008, the l'Aquila earthquake occurred. Additional logical analysis envisages the possibility of distinguishing some kind of "elementary" constituents of a "crustal storm", which can be briefly called "crustal substorms". The concept of "storm" and "substorm" is a common logical aspect, which is shared by several phenomena, depending on their common intrinsic and primary logical properties that can be called lognormality and fractality. Compared to a "crustal storm", a "crustal substorm" is likely to be reckoned to some specific seismic event. Owing to brevity purposes, however, the discussion of "substorms" is given elsewhere. AE is an effective tool for monitoring these phenomena, and other processes that are ongoing within the crust. Eventually they result to be precursors of some more or less violent earthquake. It should be stressed, however, that the target of AE monitoring is diagnosing the Earth's crust. In contrast, earthquake prediction implies a much different perspective, which makes sense only by means of more detailed multiparametric monitoring. An AE array can provide real physical information only about the processes that are objectively ongoing inside different and contiguous large slabs of the crust. The purpose is to monitor the stress propagation that crosses different regions, in order to envisage where and when it can eventually trigger a catastrophe of the system. The conclusion is that continental - or planetary - scale arrays of AE monitoring stations, which record a few different AE frequencies, appear to be the likely first step for diagnosing the evolution of local structures preceding an earthquake. On the other hand, as it is well known, the magnitude of the shock is to be related to the elastic energy stored in the focal volume, rather than to the trigger that starts it.

  8. Natural phenomena evaluations of the K-25 site UF{sub 6} cylinder storage yards

    SciT

    Fricke, K.E.

    1996-09-15

    The K-25 Site UF{sub 6} cylinder storage yards are used for the temporary storage of UF{sub 6} normal assay cylinders and long-term storage of other UF{sub 6} cylinders. The K-25 Site UF{sub 6} cylinder storage yards consist of six on-site areas: K-1066-B, K-1066-E, K-1066-F, K-1066-J, K-1066-K and K-1066-L. There are no permanent structures erected on the cylinder yards, except for five portable buildings. The operating contractor for the K-25 Site is preparing a Safety Analysis Report (SAR) to examine the safety related aspects of the K-25 Site UF{sub 6} cylinder storage yards. The SAR preparation encompasses many tasks terminating inmore » consequence analysis for the release of gaseous and liquid UF{sub 6}, one of which is the evaluation of natural phenomena threats, such as earthquakes, floods, and winds. In support of the SAR, the six active cylinder storage yards were evaluated for vulnerabilities to natural phenomena, earthquakes, high winds and tornados, tornado-generated missiles, floods (local and regional), and lightning. This report summarizes those studies. 30 refs.« less

  9. Unraveling earthquake stresses: Insights from dynamically triggered and induced earthquakes

    NASA Astrophysics Data System (ADS)

    Velasco, A. A.; Alfaro-Diaz, R. A.

    2017-12-01

    Induced seismicity, earthquakes caused by anthropogenic activity, has more than doubled in the last several years resulting from practices related to oil and gas production. Furthermore, large earthquakes have been shown to promote the triggering of other events within two fault lengths (static triggering), due to static stresses caused by physical movement along the fault, and also remotely from the passage of seismic waves (dynamic triggering). Thus, in order to understand the mechanisms for earthquake failure, we investigate regions where natural, induced, and dynamically triggered events occur, and specifically target Oklahoma. We first analyze data from EarthScope's USArray Transportable Array (TA) and local seismic networks implementing an optimized (STA/LTA) detector in order to develop local detection and earthquake catalogs. After we identify triggered events through statistical analysis, and perform a stress analysis to gain insight on the stress-states leading to triggered earthquake failure. We use our observations to determine the role of different transient stresses in contributing to natural and induced seismicity by comparing these stresses to regional stress orientation. We also delineate critically stressed regions of triggered seismicity that may indicate areas susceptible to earthquake hazards associated with sustained fluid injection in provinces of induced seismicity. Anthropogenic injection and extraction activity can alter the stress state and fluid flow within production basins. By analyzing the stress release of these ancient faults caused by dynamic stresses, we may be able to determine if fluids are solely responsible for increased seismic activity in induced regions.

  10. Identification of Deep Earthquakes

    DTIC Science & Technology

    2010-09-01

    discriminants that will reliably separate small, crustal earthquakes (magnitudes less than about 4 and depths less than about 40 to 50 km) from small...characteristics on discrimination plots designed to separate nuclear explosions from crustal earthquakes. Thus, reliably flagging these small, deep events is...Further, reliably identifying subcrustal earthquakes will allow us to eliminate deep events (previously misidentified as crustal earthquakes) from

  11. Earthquake Potential in Myanmar

    NASA Astrophysics Data System (ADS)

    Aung, Hla Hla

    Myanmar region is generally believed to be an area of high earthquake potential from the point of view of seismic activity which has been low compared to the surrounding regions like Indonesia, China, and Pakistan. Geoscientists and seismologists predicted earthquakes to occur in the area north of the Sumatra-Andaman Islands, i.e. the southwest and west part of Myanmar. Myanmar tectonic setting relative to East and SE Asia is rather peculiar and unique with different plate tectonic models but similar to the setting of western part of North America. Myanmar crustal blocks are caught within two lithospheric plates of India and Indochina experiencing oblique subduction with major dextral strike-slip faulting of the Sagaing fault. Seismic tomography and thermal structure of India plate along the Sunda subduction zone vary from south to north. Strong partitioning in central Andaman basin where crustal fragmentation and northward dispersion of Burma plate by back-arc spreading mechanism has been operating since Neogene. Northward motion of Burma plate relative to SE Asia would dock against the major continent further north and might have caused the accumulation of strain which in turn will be released as earthquakes in the future.

  12. Revisiting the 1872 Owens Valley, California, Earthquake

    Hough, S.E.; Hutton, K.

    2008-01-01

    The 26 March 1872 Owens Valley earthquake is among the largest historical earthquakes in California. The felt area and maximum fault displacements have long been regarded as comparable to, if not greater than, those of the great San Andreas fault earthquakes of 1857 and 1906, but mapped surface ruptures of the latter two events were 2-3 times longer than that inferred for the 1872 rupture. The preferred magnitude estimate of the Owens Valley earthquake has thus been 7.4, based largely on the geological evidence. Reinterpreting macroseismic accounts of the Owens Valley earthquake, we infer generally lower intensity values than those estimated in earlier studies. Nonetheless, as recognized in the early twentieth century, the effects of this earthquake were still generally more dramatic at regional distances than the macroseismic effects from the 1906 earthquake, with light damage to masonry buildings at (nearest-fault) distances as large as 400 km. Macroseismic observations thus suggest a magnitude greater than that of the 1906 San Francisco earthquake, which appears to be at odds with geological observations. However, while the mapped rupture length of the Owens Valley earthquake is relatively low, the average slip was high. The surface rupture was also complex and extended over multiple fault segments. It was first mapped in detail over a century after the earthquake occurred, and recent evidence suggests it might have been longer than earlier studies indicated. Our preferred magnitude estimate is Mw 7.8-7.9, values that we show are consistent with the geological observations. The results of our study suggest that either the Owens Valley earthquake was larger than the 1906 San Francisco earthquake or that, by virtue of source properties and/or propagation effects, it produced systematically higher ground motions at regional distances. The latter possibility implies that some large earthquakes in California will generate significantly larger ground motions than San

  13. Focal mechanisms of earthquakes in Mongolia

    NASA Astrophysics Data System (ADS)

    Sodnomsambuu, D.; Natalia, R.; Gangaadorj, B.; Munkhuu, U.; Davaasuren, G.; Danzansan, E.; Yan, R.; Valentina, M.; Battsetseg, B.

    2011-12-01

    Focal mechanism data provide information on the relative magnitudes of the principal stresses, so that a tectonic regime can be assigned. Especially such information is useful for the study of intraplate seismic active regions. A study of earthquake focal mechanisms in the territory of Mongolia as landlocked and intraplate region was conducted. We present map of focal mechanisms of earthquakes with M4.5 which occurred in Mongolia and neighboring regions. Focal mechanisms solutions were constrained by the first motion solutions, as well as by waveform modeling, particularly CMT solutions. Four earthquakes have been recorded in Mongolia in XX century with magnitude more than 8, the 1905 M7.9 Tsetserleg and M8.4 Bolnai earthquakes, the 1931 M8.0 Fu Yun earthquake, the 1957 M8.1 Gobi-Altai earthquake. However the map of focal mechanisms of earthquakes in Mongolia allows seeing all seismic active structures: Gobi Altay, Mongolian Altay, active fringe of Hangay dome, Hentii range etc. Earthquakes in the most of Mongolian territory and neighboring China regions are characterized by strike-slip and reverse movements. Strike-slip movements also are typical for earthquakes in Altay Range in Russia. The north of Mongolia and south part of the Baikal area is a region where have been occurred earthquakes with different focal mechanisms. This region is a zone of the transition between compressive regime associated to India-Eurasian collision and extensive structures localized in north of the country as Huvsgul area and Baykal rift. Earthquakes in the Baikal basin itself are characterized by normal movements. Earthquakes in Trans-Baikal zone and NW of Mongolia are characterized dominantly by strike-slip movements. Analysis of stress-axis orientations, the tectonic stress tensor is presented. The map of focal mechanisms of earthquakes in Mongolia could be useful tool for researchers in their study on Geodynamics of Central Asia, particularly of Mongolian and Baikal regions.

  14. Investigating Lushan Earthquake Victims' Individual Behavior Response and Rescue Organization.

    PubMed

    Kang, Peng; Lv, Yipeng; Deng, Qiangyu; Liu, Yuan; Zhang, Yi; Liu, Xu; Zhang, Lulu

    2017-12-11

    Research concerning the impact of earthquake victims' individual behavior and its association with earthquake-related injuries is lacking. This study examined this relationship along with effectiveness of earthquake rescue measures. The six most severely destroyed townships during the Lushan earthquake were examined; 28 villages and three earthquake victims' settlement camp areas were selected as research areas. Inclusion criteria comprised living in Lushan county for a longtime, living in Lushan county during the 2013 Lushan earthquake, and having one's home destroyed. Earthquake victims with an intellectual disability or communication problems were excluded. The earthquake victims (N (number) = 5165, male = 2396) completed a questionnaire (response rate: 94.7%). Among them, 209 were injured (5.61%). Teachers (p < 0.0001, OR (odds ratios) = 3.33) and medical staff (p = 0.001, OR = 4.35) were more vulnerable to the earthquake than were farmers. Individual behavior was directly related to injuries, such as the first reaction after earthquake and fear. There is an obvious connection between earthquake-related injury and individual behavior characteristics. It is strongly suggested that victims receive mental health support from medical practitioners and the government to minimize negative effects. The initial reaction after an earthquake also played a vital role in victims' trauma; therefore, earthquake-related experience and education may prevent injuries. Self-aid and mutual help played key roles in emergency, medical rescue efforts.

  15. Are Lowered Socioeconomic Circumstances Causally Related to Tooth Loss? A Natural Experiment Involving the 2011 Great East Japan Earthquake.

    PubMed

    Matsuyama, Yusuke; Aida, Jun; Tsuboya, Toru; Hikichi, Hiroyuki; Kondo, Katsunori; Kawachi, Ichiro; Osaka, Ken

    2017-07-01

    Oral health status is correlated with socioeconomic status. However, the causal nature of the relationship is not established. Here we describe a natural experiment involving deteriorating socioeconomic circumstances following exposure to the 2011 Great East Japan Earthquake and Tsunami. We investigated the relationship between subjective economic deterioration and housing damage due to the disaster and tooth loss in a cohort of community-dwelling residents (n = 3,039), from whom we obtained information about socioeconomic status and health status in 2010 (i.e., predating the disaster). A follow-up survey was performed in 2013 (postdisaster), and 82.1% of the 4,380 eligible survivors responded. We estimated the impact of subjective economic deterioration and housing damage due to the disaster on tooth loss by fitting an instrumental variable probit model. Subjective economic deterioration and housing damage due to the disaster were significantly associated with 8.1% and 1.7% increases in the probability of tooth loss (probit coefficients were 0.469 (95% confidence interval: 0.065, 0.872) and 0.103 (95% confidence interval: 0.011, 0.196), respectively). In this natural experiment, we confirmed the causal relationship between deteriorating socioeconomic circumstances and tooth loss. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Large earthquakes and creeping faults

    Harris, Ruth A.

    2017-01-01

    Faults are ubiquitous throughout the Earth's crust. The majority are silent for decades to centuries, until they suddenly rupture and produce earthquakes. With a focus on shallow continental active-tectonic regions, this paper reviews a subset of faults that have a different behavior. These unusual faults slowly creep for long periods of time and produce many small earthquakes. The presence of fault creep and the related microseismicity helps illuminate faults that might not otherwise be located in fine detail, but there is also the question of how creeping faults contribute to seismic hazard. It appears that well-recorded creeping fault earthquakes of up to magnitude 6.6 that have occurred in shallow continental regions produce similar fault-surface rupture areas and similar peak ground shaking as their locked fault counterparts of the same earthquake magnitude. The behavior of much larger earthquakes on shallow creeping continental faults is less well known, because there is a dearth of comprehensive observations. Computational simulations provide an opportunity to fill the gaps in our understanding, particularly of the dynamic processes that occur during large earthquake rupture and arrest.

  17. Faulting apparently related to the 1994 Northridge, California, earthquake and possible co-seismic origin of surface cracks in Potrero Canyon, Los Angeles County, California

    Catchings, R.D.; Goldman, M.R.; Lee, W.H.K.; Rymer, M.J.; Ponti, D.J.

    1998-01-01

    Apparent southward-dipping, reverse-fault zones are imaged to depths of about 1.5 km beneath Potrero Canyon, Los Angeles County, California. Based on their orientation and projection to the surface, we suggest that the imaged fault zones are extensions of the Oak Ridge fault. Geologic mapping by others and correlations with seismicity studies suggest that the Oak Ridge fault is the causative fault of the 17 January 1994 Northridge earthquake (Northridge fault). Our seismically imaged faults may be among several faults that collectively comprise the Northridge thrust fault system. Unusually strong shaking in Potrero Canyon during the Northridge earthquake may have resulted from focusing of seismic energy or co-seismic movement along existing, related shallow-depth faults. The strong shaking produced ground-surface cracks and sand blows distributed along the length of the canyon. Seismic reflection and refraction images show that shallow-depth faults may underlie some of the observed surface cracks. The relationship between observed surface cracks and imaged faults indicates that some of the surface cracks may have developed from nontectonic alluvial movement, but others may be fault related. Immediately beneath the surface cracks, P-wave velocities are unusually low (<400 m/sec), and there are velocity anomalies consistent with a seismic reflection image of shallow faulting to depths of at least 100 m. On the basis of velocity data, we suggest that unconsolidated soils (<800 m/sec) extend to depths of about 15 to 20 m beneath our datum (<25 m below ground surface). The underlying rocks range in velocity from about 1000 to 5000 m/sec in the upper 100 m. This study illustrates the utility of high-resolution seismic imaging in assessing local and regional seismic hazards.

  18. Membrane Transport Phenomena (MTP)

    NASA Technical Reports Server (NTRS)

    Mason, Larry W.

    1997-01-01

    The third semi-annual period of the MTP project has been involved with performing experiments using the Membrane Transport Apparatus (MTA), development of analysis techniques for the experiment results, analytical modeling of the osmotic transport phenomena, and completion of a DC-9 microgravity flight to test candidate fluid cell geometries. Preparations were also made for the MTP Science Concept Review (SCR), held on 13 June 1997 at Lockheed Martin Astronautics in Denver. These activities are detailed in the report.

  19. Paramutation phenomena in plants.

    PubMed

    Pilu, Roberto

    2015-08-01

    Paramutation is a particular epigenetic phenomenon discovered in Zea mays by Alexander Brink in the 1950s, and then also found in other plants and animals. Brink coined the term paramutation (from the Greek syllable "para" meaning beside, near, beyond, aside) in 1958, with the aim to differentiate paramutation from mutation. The peculiarity of paramutation with respect to other gene silencing phenomena consists in the ability of the silenced allele (named paramutagenic) to silence the other allele (paramutable) present in trans. The newly silenced (paramutated) allele remains stable in the next generations even after segregation from the paramutagenic allele and acquires paramutagenic ability itself. The inheritance behaviour of these epialleles permits a fast diffusion of a particular gene expression level/phenotype in a population even in the absence of other evolutionary influences, thus breaking the Hardy-Weinberg law. As with other gene silencing phenomena such as quelling in the fungus Neurospora crassa, transvection in Drosophila, co-suppression and virus-induced gene silencing (VIGS) described in transgenic plants and RNA interference (RNAi) in the nematode Caenorhabditis elegans, paramutation occurs without changes in the DNA sequence. So far the molecular basis of paramutation remains not fully understood, although many studies point to the involvement of RNA causing changes in DNA methylation and chromatin structure of the silenced genes. In this review I summarize all paramutation phenomena described in plants, focusing on the similarities and differences between them. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Streamflow and water well responses to earthquakes.

    PubMed

    Montgomery, David R; Manga, Michael

    2003-06-27

    Earthquake-induced crustal deformation and ground shaking can alter stream flow and water levels in wells through consolidation of surficial deposits, fracturing of solid rocks, aquifer deformation, and the clearing of fracture-filling material. Although local conditions affect the type and amplitude of response, a compilation of reported observations of hydrological response to earthquakes indicates that the maximum distance to which changes in stream flow and water levels in wells have been reported is related to earthquake magnitude. Detectable streamflow changes occur in areas within tens to hundreds of kilometers of the epicenter, whereas changes in groundwater levels in wells can occur hundreds to thousands of kilometers from earthquake epicenters.

  1. Technical basis, supporting information, and strategy for development and implementation of DOE policy for natural phenomena hazards

    SciT

    Murray, R.C.

    1991-09-01

    Policy for addressing natural phenomenon comprises a hierarchy of interrelated documents. The top level of policy is contained in the code of Federal Regulations which establishes the framework and intent to ensure overall safety of DOE facilities when subjected to the effects of natural phenomena. The natural phenomena to be considered include earthquakes and tsunami, winds, hurricanes and tornadoes, floods, volcano effects and seiches. Natural phenomena criteria have been established for design of new facilities; evaluation of existing facilities; additions, modifications, and upgrades to existing facilities; and evaluation criteria for new or existing sites. Steps needed to implement these fourmore » general criteria are described. The intent of these criteria is to identify WHAT needs to be done to ensure adequate protection from natural phenomena. The commentary provides discussion of WHY this is needed for DOE facilities within the complex. Implementing procedures identifying HOW to carry out these criteria are next identified. Finally, short and long term tasks needed to identify the implementing procedure are tabulated. There is an overall need for consistency throughout the DOE complex related to natural phenomena including consistent terminology, policy, and implementation. 1 fig, 6 tabs.« less

  2. Earthquake potential revealed by tidal influence on earthquake size-frequency statistics

    NASA Astrophysics Data System (ADS)

    Ide, Satoshi; Yabe, Suguru; Tanaka, Yoshiyuki

    2016-11-01

    The possibility that tidal stress can trigger earthquakes is long debated. In particular, a clear causal relationship between small earthquakes and the phase of tidal stress is elusive. However, tectonic tremors deep within subduction zones are highly sensitive to tidal stress levels, with tremor rate increasing at an exponential rate with rising tidal stress. Thus, slow deformation and the possibility of earthquakes at subduction plate boundaries may be enhanced during periods of large tidal stress. Here we calculate the tidal stress history, and specifically the amplitude of tidal stress, on a fault plane in the two weeks before large earthquakes globally, based on data from the global, Japanese, and Californian earthquake catalogues. We find that very large earthquakes, including the 2004 Sumatran, 2010 Maule earthquake in Chile and the 2011 Tohoku-Oki earthquake in Japan, tend to occur near the time of maximum tidal stress amplitude. This tendency is not obvious for small earthquakes. However, we also find that the fraction of large earthquakes increases (the b-value of the Gutenberg-Richter relation decreases) as the amplitude of tidal shear stress increases. The relationship is also reasonable, considering the well-known relationship between stress and the b-value. This suggests that the probability of a tiny rock failure expanding to a gigantic rupture increases with increasing tidal stress levels. We conclude that large earthquakes are more probable during periods of high tidal stress.

  3. Anomalous decrease in relatively large shocks and increase in the p and b values preceding the April 16, 2016, M7.3 earthquake in Kumamoto, Japan

    NASA Astrophysics Data System (ADS)

    Nanjo, K. Z.; Yoshida, A.

    2017-01-01

    The 2016 Kumamoto earthquakes in Kyushu, Japan, started with a magnitude ( M) 6.5 quake on April 14 on the Hinagu fault zone (FZ), followed by active seismicity including an M6.4 quake. Eventually, an M7.3 quake occurred on April 16 on the Futagawa FZ. We investigated if any sign indicative of the M7.3 quake could be found in the space-time changes in seismicity after the M6.5 quake. As a quality control, we determined in advance the threshold magnitude, above which all earthquakes are completely recorded. We then showed that the occurrence rate of relatively large ( M ≥ 3) earthquakes significantly decreased 1 day before the M7.3 quake. Significance of this decrease was evaluated by one standard deviation of sampled changes in the rate of occurrence. We next confirmed that seismicity with M ≥ 3 was well modeled by the Omori-Utsu law with p 1.5 ± 0.3, which indicates that the temporal decay of seismicity was significantly faster than a typical decay with p = 1. The larger p value was obtained when we used data of the longer time period in the analysis. This significance was confirmed by a bootstrapping approach. Our detailed analysis shows that the large p value was caused by the rapid decay of the seismicity in the northern area around the Futagawa FZ. Application of the slope (the b value) of the Gutenberg-Richter frequency-magnitude distribution to the spatiotemporal change in the seismicity revealed that the b value in the northern area increased significantly, the increase being Δ b = 0.3-0.5. Significance was verified by a statistical test of Δ b and a test using bootstrapping errors. Based on our findings, combined with the results obtained by a stress inversion analysis performed by the National Research Institute for Earth Science and Disaster Resilience, we suggested that stress near the Futagawa FZ had reduced just prior to the occurrence of the M7.3 quake. We proposed, with some other observations, that a reduction in stress might have been

  4. Earthquakes in Arkansas and vicinity 1699-2010

    Dart, Richard L.; Ausbrooks, Scott M.

    2011-01-01

    This map summarizes approximately 300 years of earthquake activity in Arkansas. It is one in a series of similar State earthquake history maps. Work on the Arkansas map was done in collaboration with the Arkansas Geological Survey. The earthquake data plotted on the map are from several sources: the Arkansas Geological Survey, the Center for Earthquake Research and Information, the National Center for Earthquake Engineering Research, and the Mississippi Department of Environmental Quality. In addition to earthquake locations, other materials presented include seismic hazard and isoseismal maps and related text. Earthquakes are a legitimate concern in Arkansas and parts of adjacent states. Arkansas has undergone a number of significant felt earthquakes since 1811. At least two of these events caused property damage: a magnitude 4.7 earthquake in 1931, and a magnitude 4.3 earthquake in 1967. The map shows all historical and instrumentally located earthquakes in Arkansas and vicinity between 1811 and 2010. The largest historic earthquake in the vicinity of the State was an intensity XI event, on December 16, 1811; the first earthquake in the New Madrid sequence. This violent event and the earthquakes that followed caused considerable damage to the then sparsely settled region.

  5. Thermal Infrared Anomalies of Several Strong Earthquakes

    PubMed Central

    Wei, Congxin; Guo, Xiao; Qin, Manzhong

    2013-01-01

    In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of “time-frequency relative power spectrum.” (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting. PMID:24222728

  6. Thermal infrared anomalies of several strong earthquakes.

    PubMed

    Wei, Congxin; Zhang, Yuansheng; Guo, Xiao; Hui, Shaoxing; Qin, Manzhong; Zhang, Ying

    2013-01-01

    In the history of earthquake thermal infrared research, it is undeniable that before and after strong earthquakes there are significant thermal infrared anomalies which have been interpreted as preseismic precursor in earthquake prediction and forecasting. In this paper, we studied the characteristics of thermal radiation observed before and after the 8 great earthquakes with magnitude up to Ms7.0 by using the satellite infrared remote sensing information. We used new types of data and method to extract the useful anomaly information. Based on the analyses of 8 earthquakes, we got the results as follows. (1) There are significant thermal radiation anomalies before and after earthquakes for all cases. The overall performance of anomalies includes two main stages: expanding first and narrowing later. We easily extracted and identified such seismic anomalies by method of "time-frequency relative power spectrum." (2) There exist evident and different characteristic periods and magnitudes of thermal abnormal radiation for each case. (3) Thermal radiation anomalies are closely related to the geological structure. (4) Thermal radiation has obvious characteristics in abnormal duration, range, and morphology. In summary, we should be sure that earthquake thermal infrared anomalies as useful earthquake precursor can be used in earthquake prediction and forecasting.

  7. Earthquake source properties from pseudotachylite

    Beeler, Nicholas M.; Di Toro, Giulio; Nielsen, Stefan

    2016-01-01

    The motions radiated from an earthquake contain information that can be interpreted as displacements within the source and therefore related to stress drop. Except in a few notable cases, the source displacements can neither be easily related to the absolute stress level or fault strength, nor attributed to a particular physical mechanism. In contrast paleo-earthquakes recorded by exhumed pseudotachylite have a known dynamic mechanism whose properties constrain the co-seismic fault strength. Pseudotachylite can also be used to directly address a longstanding discrepancy between seismologically measured static stress drops, which are typically a few MPa, and much larger dynamic stress drops expected from thermal weakening during localized slip at seismic speeds in crystalline rock [Sibson, 1973; McKenzie and Brune, 1969; Lachenbruch, 1980; Mase and Smith, 1986; Rice, 2006] as have been observed recently in laboratory experiments at high slip rates [Di Toro et al., 2006a]. This note places pseudotachylite-derived estimates of fault strength and inferred stress levels within the context and broader bounds of naturally observed earthquake source parameters: apparent stress, stress drop, and overshoot, including consideration of roughness of the fault surface, off-fault damage, fracture energy, and the 'strength excess'. The analysis, which assumes stress drop is related to corner frequency by the Madariaga [1976] source model, is restricted to the intermediate sized earthquakes of the Gole Larghe fault zone in the Italian Alps where the dynamic shear strength is well-constrained by field and laboratory measurements. We find that radiated energy exceeds the shear-generated heat and that the maximum strength excess is ~16 MPa. More generally these events have inferred earthquake source parameters that are rate, for instance a few percent of the global earthquake population has stress drops as large, unless: fracture energy is routinely greater than existing models allow

  8. Magnetic resonance microscopy for assessment of morphological changes in hydrating hydroxypropylmethylcellulose matrix tablets in situ-is it possible to detect phenomena related to drug dissolution within the hydrated matrices?

    PubMed

    Kulinowski, Piotr; Młynarczyk, Anna; Jasiński, Krzysztof; Talik, Przemysław; Gruwel, Marco L H; Tomanek, Bogusław; Węglarz, Władysław P; Dorożyński, Przemysław

    2014-09-01

    So far, the hydrated part of the HPMC matrix has commonly been denoted as a "gel" or "pseudogel" layer. No MRI-based results have been published regarding observation of internal phenomena related to drug dissolution inside swelling polymeric matrices during hydration. The purpose of the study was to detect such phenomena. Multiparametric, spatially and temporally resolved T2 MR relaxometry, in situ, was applied to study formation of the hydration progress in HPMC matrix tablets loaded with L-dopa and ketoprofen using a 11.7 T MRI system. Two spin-echo based pulse sequences were used, one of them specifically designed to study short T2 signals. Two components in the T2 decay envelope were estimated and spatial distributions of their parameters, i.e. amplitudes and T2 values, were obtained. Based on the data, different region formation patterns (i.e. multilayer structure) were registered depending on drug presence and solubility. Inside the matrix with incorporated sparingly soluble drug a specific layer formation due to drug dissolution was detected, whereas a matrix with very slightly soluble drug does not form distinct external "gel-like" layer. We have introduced a new paradigm in the characterization of hydrating matrices using (1)H MRI methods. It reflects molecular mobility and concentration of water inside the hydrated matrix. For the first time, drug dissolution related phenomena, i.e. particular front and region formation, were observed by MRI methods.

  9. A smartphone application for earthquakes that matter!

    NASA Astrophysics Data System (ADS)

    Bossu, Rémy; Etivant, Caroline; Roussel, Fréderic; Mazet-Roux, Gilles; Steed, Robert

    2014-05-01

    Smartphone applications have swiftly become one of the most popular tools for rapid reception of earthquake information for the public, some of them having been downloaded more than 1 million times! The advantages are obvious: wherever someone's own location is, they can be automatically informed when an earthquake has struck. Just by setting a magnitude threshold and an area of interest, there is no longer the need to browse the internet as the information reaches you automatically and instantaneously! One question remains: are the provided earthquake notifications always relevant for the public? What are the earthquakes that really matters to laypeople? One clue may be derived from some newspaper reports that show that a while after damaging earthquakes many eyewitnesses scrap the application they installed just after the mainshock. Why? Because either the magnitude threshold is set too high and many felt earthquakes are missed, or it is set too low and the majority of the notifications are related to unfelt earthquakes thereby only increasing anxiety among the population at each new update. Felt and damaging earthquakes are the ones that matter the most for the public (and authorities). They are the ones of societal importance even when of small magnitude. A smartphone application developed by EMSC (Euro-Med Seismological Centre) with the financial support of the Fondation MAIF aims at providing suitable notifications for earthquakes by collating different information threads covering tsunamigenic, potentially damaging and felt earthquakes. Tsunamigenic earthquakes are considered here to be those ones that are the subject of alert or information messages from the PTWC (Pacific Tsunami Warning Centre). While potentially damaging earthquakes are identified through an automated system called EQIA (Earthquake Qualitative Impact Assessment) developed and operated at EMSC. This rapidly assesses earthquake impact by comparing the population exposed to each expected

  10. Damage instability and Earthquake nucleation

    NASA Astrophysics Data System (ADS)

    Ionescu, I. R.; Gomez, Q.; Campillo, M.; Jia, X.

    2017-12-01

    Earthquake nucleation (initiation) is usually associated to the loss of the stability of the geological structure under a slip-weakening friction acting on the fault. The key parameters involved in the stability of the fault are the stress drop, the critical slip distance but also the elastic stiffness of the surrounding materials (rocks). We want to explore here how the nucleation phenomena are correlated to the material softening during damage accumulation by dynamic and/or quasi-static processes. Since damage models are describing micro-cracks growth, which is generally an unstable phenomenon, it is natural to expect some loss of stability on the associated micro-mechanics based models. If the model accurately captures the material behavior, then this can be due to the unstable nature of the brittle material itself. We obtained stability criteria at the microscopic scale, which are related to a large class of damage models. We show that for a given continuous strain history the quasi-static or dynamic problems are instable or ill-posed (multiplicity of material responses) and whatever the selection rule is adopted, shocks (time discontinuities) will occur. We show that the quasi-static equilibria chosen by the "perfect delay convention" is always stable. These stability criteria are used to analyze how NIC (Non Interacting Crack) effective elasticity associated to "self similar growth" model work in some special configurations (one family of micro-cracks in mode I, II and III and in plane strain or plain stress). In each case we determine a critical crack density parameter and critical micro-crack radius (length) which distinguish between stable and unstable behaviors. This critical crack density depends only on the chosen configuration and on the Poisson ratio.

  11. Earthquake likelihood model testing

    Schorlemmer, D.; Gerstenberger, M.C.; Wiemer, S.; Jackson, D.D.; Rhoades, D.A.

    2007-01-01

    INTRODUCTIONThe Regional Earthquake Likelihood Models (RELM) project aims to produce and evaluate alternate models of earthquake potential (probability per unit volume, magnitude, and time) for California. Based on differing assumptions, these models are produced to test the validity of their assumptions and to explore which models should be incorporated in seismic hazard and risk evaluation. Tests based on physical and geological criteria are useful but we focus on statistical methods using future earthquake catalog data only. We envision two evaluations: a test of consistency with observed data and a comparison of all pairs of models for relative consistency. Both tests are based on the likelihood method, and both are fully prospective (i.e., the models are not adjusted to fit the test data). To be tested, each model must assign a probability to any possible event within a specified region of space, time, and magnitude. For our tests the models must use a common format: earthquake rates in specified “bins” with location, magnitude, time, and focal mechanism limits.Seismology cannot yet deterministically predict individual earthquakes; however, it should seek the best possible models for forecasting earthquake occurrence. This paper describes the statistical rules of an experiment to examine and test earthquake forecasts. The primary purposes of the tests described below are to evaluate physical models for earthquakes, assure that source models used in seismic hazard and risk studies are consistent with earthquake data, and provide quantitative measures by which models can be assigned weights in a consensus model or be judged as suitable for particular regions.In this paper we develop a statistical method for testing earthquake likelihood models. A companion paper (Schorlemmer and Gerstenberger 2007, this issue) discusses the actual implementation of these tests in the framework of the RELM initiative.Statistical testing of hypotheses is a common task and a

  12. Geophysical observations of Kilauea volcano, Hawaii, 1. temporal gravity variations related to the 29 November, 1975, M = 7.2 earthquake and associated summit collapse

    Jachens, R.C.; Eaton, G.P.

    1980-01-01

    Repeated high-precision gravity measurements made near the summit of Kilauea volcano, Hawaii, have revealed systematic temporal variations in the gravity field associated with a major deflation of the volcano that followed the 29 November, 1975, earthquake and eruption. Changes in the gravity field with respect to a stable reference station on the south flank of neighboring Mauna Loa volcano were measured at 18 sites in the summit region of Kilauea and at 4 sites far removed from its summit. The original survey, conducted 10-23 November, 1975, was repeated during a two-week period after the earthquake. The results indicate that sometime between the first survey and the latter part of the second survey the gravity field at sites near the summit increased with respect to that at sites far removed from the summit. The pattern of gravity increase is essentially radially symmetrical, with a half-width slightly less than 3 km, about the point of maximum change 1.5 km southeast of Halemaumau pit crater. Gravity changes at sites near the summit correlate closely with elevation decreases that occurred sometime between leveling surveys conducted in late September 1975 and early January 1976. The systematic relation between gravity and elevation change (-1.71 ?? 0.05 (s.e.) ??gal/cm) shows that deflation was accompanied by a loss of mass from beneath the summit region. Mass balance calculations indicate that for all reasonable magma densities, the volume of magma withdrawn from beneath the summit region exceeded the volume of summit collapse. Analysis suggests that magma drained from at least two distinct areas south of Kilauea caldera that coincide roughly with two reservoir areas active during inflation before the 1967-1968 Kilauea eruption. ?? 1980.

  13. [Resilience, social relations, and pedagogic intervention five years after the earthquake occurred in L'Aquila (Central Italy) in 2009: an action-research in the primary schools].

    PubMed

    Vaccarelli, Alessandro; Ciccozzi, Chiara; Fiorenza, Arianna

    2016-01-01

    the action-research "Outdoor training and citizenship between children from L'Aquila", carried out from 2014 to 2015 in some schools situated in the municipality of L'Aquila, aimed to answer to the needs emerged in reference to the social and psychological problems among children during the period after the L'Aquila earthquake occurred in 2009. In particular, the article provides documentary evidence about the results regarding the parts related to the study of resilience (cognitive objective) and of social relations (objective tied to the educational intervention), five years after the earthquake. the pedagogical research team, in close cooperation with the Cartography Laboratory of the University of L'Aquila and with the Grupo de Innovación Educativa Areté de la Universidad Politécnica de Madrid, has worked according to the research-action methodology, collecting secondary data and useful data to check the effectiveness of the educational actions put in place in order to promote resilient behaviours and to activate positive group dynamics. the study has been developed in 4 primary schools of the L'Aquila and has involved 83 children from 8 to 12 years. A control group made by 55 subjects, homogeneous for sex and age, has been identified in the primary schools of Borgorose, a little town near Rieti (Central Italy). data about the abilities of resilience and about the response to the stress have been collected in the first phase of the study with the purpose to outline the initial situation and develop an appropriate educational intervention. The comparison with the control group made by 55 subjects who were not from L'Aquila allowed to check that, 5 years after the disaster, the context of life produces a meaningful discrepancy in terms of responses to the stress and to the ability of resilience, and this fact is definitely negative for children from L'Aquila. On the other hand, data related to social relations allowed to verify how the educational intervention

  14. Identified EM Earthquake Precursors

    NASA Astrophysics Data System (ADS)

    Jones, Kenneth, II; Saxton, Patrick

    2014-05-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After a number of custom rock experiments, two hypotheses were formed which could answer the EM wave model. The first hypothesis concerned a sufficient and continuous electron movement either by surface or penetrative flow, and the second regarded a novel approach to radio transmission. Electron flow along fracture surfaces was determined to be inadequate in creating strong EM fields, because rock has a very high electrical resistance making it a high quality insulator. Penetrative flow could not be corroborated as well, because it was discovered that rock was absorbing and confining electrons to a very thin skin depth. Radio wave transmission and detection worked with every single test administered. This hypothesis was reviewed for propagating, long-wave generation with sufficient amplitude, and the capability of penetrating solid rock. Additionally, fracture spaces, either air or ion-filled, can facilitate this concept from great depths and allow for surficial detection. A few propagating precursor signals have been detected in the field occurring with associated phases using custom-built loop antennae. Field testing was conducted in Southern California from 2006-2011, and outside the NE Texas town of Timpson in February, 2013. The antennae have mobility and observations were noted for

  15. Slow slip phenomena in Cascadia from 2007 and beyond: a review

    Gomberg, Joan; ,

    2010-01-01

    Recent technological advances combined with more detailed analyses of seismologic and geodetic observations have fundamentally changed our understanding of the ways in which tectonic stresses arising from plate motions are accommodated by slip on faults. The traditional view that relative plate motions are accommodated by a simple cycle of stress accumulation and release on “locked” plate-boundary faults has been revolutionized by the serendipitous discovery and recognition of the significance of slow-slip phenomena, mostly in the deeper reaches of subduction zones. The Cascadia subduction zone, located in the Pacific Northwest of the conterminous United States and adjacent Canada, is an archetype of exploration and learning about slow-slip phenomena. These phenomena are manifest as geodetically observed aseismic transient deformations accompanied by a previously unrecognized class of seismic signals. Although secondary failure processes may be involved in generating the seismic signals, the primary origins of both aseismic and seismic phenomena appear to be episodic fault slip, probably facilitated by fluids, on a plate interface that is critically stressed or weakened. In Cascadia, this transient slip evolves more slowly and over more prolonged durations relative to the slip in earthquakes, and it occurs between the 30- and 40-km-depth contours of the plate interface where information was previously elusive. Although there is some underlying organization that relaxes nearly all the accrued plate-motion stresses along the entirety of Cascadia, we now infer that slow slip evolves in complex patterns indicative of propagating stress fronts. Our new understanding provides key constraints not only on the region where the slow slip originates, but also on the probable characteristics of future megathrust earthquakes in Cascadia. Herein, we review the most significant scientific issues and progress related to understanding slow-slip phenomena in Cascadia and

  16. Wave phenomena in sunspots

    NASA Astrophysics Data System (ADS)

    Löhner-Böttcher, Johannes

    2016-03-01

    Context: The dynamic atmosphere of the Sun exhibits a wealth of magnetohydrodynamic (MHD) waves. In the presence of strong magnetic fields, most spectacular and powerful waves evolve in the sunspot atmosphere. Allover the sunspot area, continuously propagating waves generate strong oscillations in spectral intensity and velocity. The most prominent and fascinating phenomena are the 'umbral flashes' and 'running penumbral waves' as seen in the sunspot chromosphere. Their nature and relation have been under intense discussion in the last decades. Aims: Waves are suggested to propagate upward along the magnetic field lines of sunspots. An observational study is performed to prove or disprove the field-guided nature and coupling of the prevalent umbral and penumbral waves. Comprehensive spectroscopic observations at high resolution shall provide new insights into the wave characteristics and distribution across the sunspot atmosphere. Methods: Two prime sunspot observations were carried out with the Dunn Solar Telescope at the National Solar Observatory in New Mexico and with the Vacuum Tower Telescope at the Teide Observatory on Tenerife. The two-dimensional spectroscopic observations were performed with the interferometric spectrometers IBIS and TESOS. Multiple spectral lines are scanned co-temporally to sample the dynamics at the photospheric and chromospheric layers. The time series (1 - 2.5 h) taken at high spatial and temporal resolution are analyzed according to their evolution in spectral intensities and Doppler velocities. A wavelet analysis was used to obtain the wave power and dominating wave periods. A reconstruction of the magnetic field inclination based on sunspot oscillations was developed. Results and conclusions: Sunspot oscillations occur continuously in spectral intensity and velocity. The obtained wave characteristics of umbral flashes and running penumbral waves strongly support the scenario of slow-mode magnetoacoustic wave propagation along the

  17. Perspectives on earthquake hazards in the New Madrid seismic zone, Missouri

    SciT

    Thenhaus, P.C.

    1990-01-01

    A sequence of three great earthquakes struck the Central United States during the winter of 1811-12 in the area of New Madrid, Missouri. They are considered to be the greatest earthquakes in the conterminous U.S. because they were felt and caused damage at far greater distances than any other earthquakes in US history. In contrast to California, where earthquakes are felt frequently, the damaging earthquakes that have occurred in the Eastern US are generally regarded as only historical phenomena. A fundamental problem in the Eastern US, therefore, is that the earthquake hazard is not generally considered today in land-use andmore » civic planning. This article offers perspectives on the earthquake hazard of the New Madrid seismic zone through discussions of the geology of the Mississippi Embayment, the historical earthquakes that have occurred there, the earthquake risk, and the tools that geoscientists have to study the region. The so-called earthquake hazard is defined by the characterization of the physical attributes of the geological structures that cause earthquakes, the estimation of the recurrence times of the earthquakes, their potential size, and the expected ground motions. The term earthquake risk, on the other hand, refers to aspects of the expected damage to manmade structures and to lifelines as a result of the earthquake hazard.« less

  18. Wolf-Rayet phenomena

    NASA Technical Reports Server (NTRS)

    Conti, P. S.

    1982-01-01

    The properties of stars showing Wolf-Rayet phenomena are outlined along with the direction of future work. Emphasis is placed on the characteristics of W-R spectra. Specifically the following topics are covered: the absolute visual magnitudes; the heterogeneity of WN spectra; the existence of transition type spectra and compositions the mass loss rates; and the existence of very luminous and possibly very massive W-R stars. Also, a brief overview of current understanding of the theoretical aspects of stellar evolution and stellar winds and the various scenarios that have been proposed to understand W-R spectra are included.

  19. 76 FR 19123 - National Earthquake Prediction Evaluation Council (NEPEC)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ... Earthquake Prediction Evaluation Council (NEPEC) AGENCY: U.S. Geological Survey, Interior. ACTION: Notice of meeting. SUMMARY: Pursuant to Public Law 96-472, the National Earthquake Prediction Evaluation Council... proposed earthquake predictions, on the completeness and scientific validity of the available data related...

  20. 75 FR 50749 - Advisory Committee on Earthquake Hazards Reduction Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ... Earthquake Hazards Reduction Meeting AGENCY: National Institute of Standards and Technology, Department of Commerce. ACTION: Notice of open meeting. SUMMARY: The Advisory Committee on Earthquake Hazards Reduction... on NEHRP earthquake related activities and to gather information for the 2011 Annual Report of the...

  1. The relationship between earthquake exposure and posttraumatic stress disorder in 2013 Lushan earthquake

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Lu, Yi

    2018-01-01

    The objective of this study is to explore the relationship between earthquake exposure and the incidence of PTSD. A stratification random sample survey was conducted to collect data in the Longmenshan thrust fault after Lushan earthquake three years. We used the Children's Revised Impact of Event Scale (CRIES-13) and the Earthquake Experience Scale. Subjects in this study included 3944 school student survivors in local eleven schools. The prevalence of probable PTSD is relatively higher, when the people was trapped in the earthquake, was injured in the earthquake or have relatives who died in the earthquake. It concluded that researchers need to pay more attention to the children and adolescents. The government should pay more attention to these people and provide more economic support.

  2. The isolated 678-km deep 30 May 2015 MW 7.9 Ogasawara (Bonin) Islands earthquake

    NASA Astrophysics Data System (ADS)

    Ye, L.; Lay, T.; Zhan, Z.; Kanamori, H.; Hao, J.

    2015-12-01

    Deep-focus earthquakes, located 300 to 700 km below the Earth's surface within sinking slabs of relatively cold oceanic lithosphere, are mysterious phenomena. Seismic radiation from deep events is essentially indistinguishable from that for shallow stick-slip frictional-sliding earthquakes, but the confining pressure and temperature are so high for deep-focus events that a distinct process is likely needed to account for their abrupt energy release. The largest recorded deep-focus earthquake (MW 7.9) in the Izu-Bonin slab struck on 30 May 2015 beneath the Ogasawara (Bonin) Islands, isolated from prior seismicity by over 100 km in depth, and followed by only 2 small aftershocks. Globally, this is the deepest (678 km) major (MW > 7) earthquake in the seismological record. Seismicity indicates along-strike contortion of the Izu-Bonin slab, with horizontal flattening near a depth of 550 km in the Izu region and progressive steepening to near-vertical toward the south above the location of the 2015 event. Analyses of a large global data set of P, SH and pP seismic phases using short-period back-projection, subevent directivity, and broadband finite-fault inversion indicate that the mainshock ruptured a shallowly-dipping fault plane with patchy slip that spread over a distance of ~40 km with variable expansion rate (~5 km/s down-dip initially, ~3 km/s up-dip later). During the 17 s rupture duration the radiated energy was ~3.3 x 1016 J and the stress drop was ~38 MPa. The radiation efficiency is moderate (0.34), intermediate to that of the 1994 Bolivia and 2013 Sea of Okhotsk MW 8.3 earthquakes, indicating a continuum of processes. The isolated occurrence of the event suggests that localized stress concentration associated with the pronounced deformation of the Izu-Bonin slab likely played a role in generating this major earthquake.

  3. Phenomena Associated with EIT Waves

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Biesecker, D. A.; Gopalswamy, N.; Fisher, Richard R. (Technical Monitor)

    2002-01-01

    We discuss phenomena associated with 'EIT Wave' transients. These phenomena include coronal mass ejections, flares, EUV/SXR dimmings, chromospheric waves, Moreton waves, solar energetic particle events, energetic electron events, and radio signatures. Although the occurrence of many phenomena correlate with the appearance of EIT waves, it is difficult to infer which associations are causal. The presentation will include a discussion of correlation surveys of these phenomena.

  4. Phenomena Associated With EIT Waves

    NASA Technical Reports Server (NTRS)

    Thompson, B. J.; Biesecker, D. A.; Gopalswamy, N.

    2003-01-01

    We discuss phenomena associated with "EIT Wave" transients. These phenomena include coronal mass ejections, flares, EUV/SXR dimmings, chromospheric waves, Moreton waves, solar energetic particle events, energetic electron events, and radio signatures. Although the occurrence of many phenomena correlate with the appearance of EIT waves, it is difficult to mfer which associations are causal. The presentation will include a discussion of correlation surveys of these phenomena.

  5. Observing Triggered Earthquakes Across Iran with Calibrated Earthquake Locations

    NASA Astrophysics Data System (ADS)

    Karasozen, E.; Bergman, E.; Ghods, A.; Nissen, E.

    2016-12-01

    We investigate earthquake triggering phenomena in Iran by analyzing patterns of aftershock activity around mapped surface ruptures. Iran has an intense level of seismicity (> 40,000 events listed in the ISC Bulletin since 1960) due to it accommodating a significant portion of the continental collision between Arabia and Eurasia. There are nearly thirty mapped surface ruptures associated with earthquakes of M 6-7.5, mostly in eastern and northwestern Iran, offering a rich potential to study the kinematics of earthquake nucleation, rupture propagation, and subsequent triggering. However, catalog earthquake locations are subject to up to 50 km of location bias from the combination of unknown Earth structure and unbalanced station coverage, making it challenging to assess both the rupture directivity of larger events and the spatial patterns of their aftershocks. To overcome this limitation, we developed a new two-tiered multiple-event relocation approach to obtain hypocentral parameters that are minimally biased and have realistic uncertainties. In the first stage, locations of small clusters of well-recorded earthquakes at local spatial scales (100s of events across 100 km length scales) are calibrated either by using near-source arrival times or independent location constraints (e.g. local aftershock studies, InSAR solutions), using an implementation of the Hypocentroidal Decomposition relocation technique called MLOC. Epicentral uncertainties are typically less than 5 km. Then, these events are used as prior constraints in the code BayesLoc, a Bayesian relocation technique that can handle larger datasets, to yield region-wide calibrated hypocenters (1000s of events over 1000 km length scales). With locations and errors both calibrated, the pattern of aftershock activity can reveal the type of the earthquake triggering: dynamic stress changes promote an increase in the seismicity rate in the direction of unilateral propagation, whereas static stress changes should

  6. Classifying prion and prion-like phenomena.

    PubMed

    Harbi, Djamel; Harrison, Paul M

    2014-01-01

    The universe of prion and prion-like phenomena has expanded significantly in the past several years. Here, we overview the challenges in classifying this data informatically, given that terms such as "prion-like", "prion-related" or "prion-forming" do not have a stable meaning in the scientific literature. We examine the spectrum of proteins that have been described in the literature as forming prions, and discuss how "prion" can have a range of meaning, with a strict definition being for demonstration of infection with in vitro-derived recombinant prions. We suggest that although prion/prion-like phenomena can largely be apportioned into a small number of broad groups dependent on the type of transmissibility evidence for them, as new phenomena are discovered in the coming years, a detailed ontological approach might be necessary that allows for subtle definition of different "flavors" of prion / prion-like phenomena.

  7. Earthquake ethics through scientific knowledge, historical memory and societal awareness: the experience of direct internet information.

    NASA Astrophysics Data System (ADS)

    de Rubeis, Valerio; Sbarra, Paola; Sebaste, Beppe; Tosi, Patrizia

    2013-04-01

    The experience of collection of data on earthquake effects and diffusion of information to people, carried on through the site "haisentitoilterremoto.it" (didyoufeelit) managed by the Istituto Nazionale di Geofisica e Vulcanologia (INGV), has evidenced a constantly growing interest by Italian citizens. Started in 2007, the site has collected more than 520,000 compiled intensity questionnaires, producing intensity maps of almost 6,000 earthquakes. One of the most peculiar feature of this experience is constituted by a bi-directional information exchange. Every person can record observed effects of the earthquake and, at the same time, look at the generated maps. Seismologists, on the other side, can find each earthquake described in real time through its effects on the whole territory. In this way people, giving punctual information, receive global information from the community, mediated and interpreted by seismological knowledge. The relationship amongst seismologists, mass media and civil society is, thus, deep and rich. The presence of almost 20,000 permanent subscribers distributed on the whole Italian territory, alerted in case of earthquake, has reinforced the participation: the subscriber is constantly informed by the seismologists, through e-mail, about events occurred in his-her area, even if with very small magnitude. The "alert" service provides the possibility to remember that earthquakes are a phenomenon continuously present, on the other hand it shows that high magnitude events are very rare. This kind of information is helpful as it is fully complementary to that one given by media. We analyze the effects of our activity on society and mass media. The knowledge of seismic phenomena is present in each person, having roots on fear, idea of death and destruction, often with the deep belief of very rare occurrence. This position feeds refusal and repression. When a strong earthquake occurs, surprise immediately changes into shock and desperation. A

  8. Earthquakes in Mississippi and vicinity 1811-2010

    Dart, Richard L.; Bograd, Michael B.E.

    2011-01-01

    This map summarizes two centuries of earthquake activity in Mississippi. Work on the Mississippi map was done in collaboration with the Mississippi Department of Environmental Quality, Office of Geology. The earthquake data plotted on the map are from several sources: the Mississippi Department of Environmental Quality, the Center for Earthquake Research and Information, the National Center for Earthquake Engineering Research, and the Arkansas Geological Survey. In addition to earthquake locations, other materials include seismic hazard and isoseismal maps and related text. Earthquakes are a legitimate concern in Mississippi and parts of adjacent States. Mississippi has undergone a number of felt earthquakes since 1811. At least two of these events caused property damage: a magnitude 4.7 earthquake in 1931, and a magnitude 4.3 earthquake in 1967. The map shows all historical and instrumentally located earthquakes in Mississippi and vicinity between 1811 and 2010. The largest historic earthquake in the vicinity of the State was an intensity XI event, on December 16, 1811; the first earthquake in the New Madrid sequence. This violent event and the earthquakes that followed caused considerable damage to the then sparsely settled region.

  9. Correlated randomness and switching phenomena

    NASA Astrophysics Data System (ADS)

    Stanley, H. E.; Buldyrev, S. V.; Franzese, G.; Havlin, S.; Mallamace, F.; Kumar, P.; Plerou, V.; Preis, T.

    2010-08-01

    One challenge of biology, medicine, and economics is that the systems treated by these serious scientific disciplines have no perfect metronome in time and no perfect spatial architecture-crystalline or otherwise. Nonetheless, as if by magic, out of nothing but randomness one finds remarkably fine-tuned processes in time and remarkably fine-tuned structures in space. Further, many of these processes and structures have the remarkable feature of “switching” from one behavior to another as if by magic. The past century has, philosophically, been concerned with placing aside the human tendency to see the universe as a fine-tuned machine. Here we will address the challenge of uncovering how, through randomness (albeit, as we shall see, strongly correlated randomness), one can arrive at some of the many spatial and temporal patterns in biology, medicine, and economics and even begin to characterize the switching phenomena that enables a system to pass from one state to another. Inspired by principles developed by A. Nihat Berker and scores of other statistical physicists in recent years, we discuss some applications of correlated randomness to understand switching phenomena in various fields. Specifically, we present evidence from experiments and from computer simulations supporting the hypothesis that water’s anomalies are related to a switching point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell), and that the bubbles in economic phenomena that occur on all scales are not “outliers” (another Gladwell immortalization). Though more speculative, we support the idea of disease as arising from some kind of yet-to-be-understood complex switching phenomenon, by discussing data on selected examples, including heart disease and Alzheimer disease.

  10. Are Earthquakes Predictable? A Study on Magnitude Correlations in Earthquake Catalog and Experimental Data

    NASA Astrophysics Data System (ADS)

    Stavrianaki, K.; Ross, G.; Sammonds, P. R.

    2015-12-01

    The clustering of earthquakes in time and space is widely accepted, however the existence of correlations in earthquake magnitudes is more questionable. In standard models of seismic activity, it is usually assumed that magnitudes are independent and therefore in principle unpredictable. Our work seeks to test this assumption by analysing magnitude correlation between earthquakes and their aftershocks. To separate mainshocks from aftershocks, we perform stochastic declustering based on the widely used Epidemic Type Aftershock Sequence (ETAS) model, which allows us to then compare the average magnitudes of aftershock sequences to that of their mainshock. The results of earthquake magnitude correlations were compared with acoustic emissions (AE) from laboratory analog experiments, as fracturing generates both AE at the laboratory scale and earthquakes on a crustal scale. Constant stress and constant strain rate experiments were done on Darley Dale sandstone under confining pressure to simulate depth of burial. Microcracking activity inside the rock volume was analyzed by the AE technique as a proxy for earthquakes. Applying the ETAS model to experimental data allowed us to validate our results and provide for the first time a holistic view on the correlation of earthquake magnitudes. Additionally we search the relationship between the conditional intensity estimates of the ETAS model and the earthquake magnitudes. A positive relation would suggest the existence of magnitude correlations. The aim of this study is to observe any trends of dependency between the magnitudes of aftershock earthquakes and the earthquakes that trigger them.

  11. Implications of fault constitutive properties for earthquake prediction.

    PubMed

    Dieterich, J H; Kilgore, B

    1996-04-30

    The rate- and state-dependent constitutive formulation for fault slip characterizes an exceptional variety of materials over a wide range of sliding conditions. This formulation provides a unified representation of diverse sliding phenomena including slip weakening over a characteristic sliding distance Dc, apparent fracture energy at a rupture front, time-dependent healing after rapid slip, and various other transient and slip rate effects. Laboratory observations and theoretical models both indicate that earthquake nucleation is accompanied by long intervals of accelerating slip. Strains from the nucleation process on buried faults generally could not be detected if laboratory values of Dc apply to faults in nature. However, scaling of Dc is presently an open question and the possibility exists that measurable premonitory creep may precede some earthquakes. Earthquake activity is modeled as a sequence of earthquake nucleation events. In this model, earthquake clustering arises from sensitivity of nucleation times to the stress changes induced by prior earthquakes. The model gives the characteristic Omori aftershock decay law and assigns physical interpretation to aftershock parameters. The seismicity formulation predicts large changes of earthquake probabilities result from stress changes. Two mechanisms for foreshocks are proposed that describe observed frequency of occurrence of foreshock-mainshock pairs by time and magnitude. With the first mechanism, foreshocks represent a manifestation of earthquake clustering in which the stress change at the time of the foreshock increases the probability of earthquakes at all magnitudes including the eventual mainshock. With the second model, accelerating fault slip on the mainshock nucleation zone triggers foreshocks.

  12. Earthquakes: Predicting the unpredictable?

    Hough, Susan E.

    2005-01-01

    The earthquake prediction pendulum has swung from optimism in the 1970s to rather extreme pessimism in the 1990s. Earlier work revealed evidence of possible earthquake precursors: physical changes in the planet that signal that a large earthquake is on the way. Some respected earthquake scientists argued that earthquakes are likewise fundamentally unpredictable. The fate of the Parkfield prediction experiment appeared to support their arguments: A moderate earthquake had been predicted along a specified segment of the central San Andreas fault within five years of 1988, but had failed to materialize on schedule. At some point, however, the pendulum began to swing back. Reputable scientists began using the "P-word" in not only polite company, but also at meetings and even in print. If the optimism regarding earthquake prediction can be attributed to any single cause, it might be scientists' burgeoning understanding of the earthquake cycle.

  13. Earthquakes: hydrogeochemical precursors

    Ingebritsen, Steven E.; Manga, Michael

    2014-01-01

    Earthquake prediction is a long-sought goal. Changes in groundwater chemistry before earthquakes in Iceland highlight a potential hydrogeochemical precursor, but such signals must be evaluated in the context of long-term, multiparametric data sets.

  14. Tilt precursors before earthquakes on the San Andreas fault, California

    Johnston, M.J.S.; Mortensen, C.E.

    1974-01-01

    An array of 14 biaxial shallow-borehole tiltmeters (at 10-7 radian sensitivity) has been installed along 85 kilometers of the San Andreas fault during the past year. Earthquake-related changes in tilt have been simultaneously observed on up to four independent instruments. At earthquake distances greater than 10 earthquake source dimensions, there are few clear indications of tilt change. For the four instruments with the longest records (>10 months), 26 earthquakes have occurred since July 1973 with at least one instrument closer than 10 source dimensions and 8 earthquakes with more than one instrument within that distance. Precursors in tilt direction have been observed before more than 10 earthquakes or groups of earthquakes, and no similar effect has yet been seen without the occurrence of an earthquake.

  15. Thermal Wave Phenomena

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This map from the MGS Horizon Sensor Assembly (HORSE) shows middle atmospheric temperatures near the 1 mbar level of Mars between Ls 170 to 175 (approx. July 14 - 23, 1999). Local Mars times between 1:30 and 4:30 AM are included. Infrared radiation measured by the Mars Horizon Sensor Assembly was used to make the map. That device continuously views the 'limb' of Mars in four directions, to help orient the spacecraft instruments to the nadir: straight down.

    The map shows thermal wave phenomena that are caused by the large topographic variety of Mars' surface, as well the latitudinally symmetric behavior expected at this time of year near the equinox.

  16. Autoimmune phenomena following prostatectomy.

    PubMed

    Tweezer-Zaks, Nurit; Marai, Ibrahim; Livneh, Avi; Bank, Ilan; Langevitz, Pnina

    2005-09-01

    Benign prostatic hypertrophy is the most common benign tumor in males, resulting in prostatectomy in 20-30% of men who live to the age of 80. There are no data on the association of prostatectomy with autoimmune phenomena in the English-language medical literature. To report our experience with three patients who developed autoimmune disease following prostatectomy. Three patients presented awith autoimmune phenomenon soon after a prostectomy for BPH or prostatic carcinoma: one had clinically diagnosed temporal arteritis, one had leukocytoclastic vasculitis, and the third patient developed sensory Guillian-Barré syndrome following prostatectomy. In view of the temporal association between the removal of the prostate gland andthe autoimmune process, combined with previously known immunohistologic features of BPH, a cause-effect relationship probably exists.

  17. Earthquake induced landslide hazard field observatory in the Avcilar peninsula

    NASA Astrophysics Data System (ADS)

    Bigarre, Pascal; Coccia, Stella; Theoleyre, Fiona; Ergintav, Semih; Özel, Oguz; Yalçinkaya, Esref; Lenti, Luca; Martino, Salvatore; Gamba, Paolo; Zucca, Francesco; Moro, Marco

    2015-04-01

    Earthquake-triggered landslides have an increasing disastrous impact in seismic regions due to the fast growing urbanization and infrastructures. Just considering disasters from the last fifteen years, among which the 1999 Chi-Chi earthquake, the 2008 Wenchuan earthquake, and the 2011 Tohoku earthquake, these events generated tens of thousands of coseismic landslides. Those resulted in amazing death toll and considerable damages, affecting the regional landscape including its hydrological main features. Despite a strong impetus in research during past decades, knowledge on those geohazards is still fragmentary, while databases of high quality observational data are lacking. These phenomena call for further collaborative researches aiming eventually to enhance preparedness and crisis management. The MARSITE project gathers research groups in a comprehensive monitoring activity developed in the Sea of Marmara Region, one of the most densely populated parts of Europe and rated at high seismic risk level since the 1999 Izmit and Duzce devastating earthquakes. Besides the seismic threat, landslides in Turkey and in this region constitute an important source of loss. The 6th Work Package of MARSITE project gathers 9 research groups to study earthquake-induced landslides focusing on two sub-regional areas of high interest among which the Cekmece-Avcilar peninsula, located westwards of Istanbul, as a highly urbanized concentrated landslide prone area, showing high susceptibility to both rainfalls while affected by very significant seismic site effects. A multidisciplinary research program based on pre-existing studies has been designed with objectives and tasks linked to constrain and tackle progressively some challenging issues related to data integration, modeling, monitoring and mapping technologies. Since the start of the project, progress has been marked on several important points as follows. The photogeological interpretation and analysis of ENVISAT-ERS DIn

  18. Redefining Earthquakes and the Earthquake Machine

    ERIC Educational Resources Information Center

    Hubenthal, Michael; Braile, Larry; Taber, John

    2008-01-01

    The Earthquake Machine (EML), a mechanical model of stick-slip fault systems, can increase student engagement and facilitate opportunities to participate in the scientific process. This article introduces the EML model and an activity that challenges ninth-grade students' misconceptions about earthquakes. The activity emphasizes the role of models…

  19. Important Earthquake Engineering Resources

    PEER logo Pacific Earthquake Engineering Research Center home about peer news events research Engineering Resources Site Map Search Important Earthquake Engineering Resources - American Concrete Institute Motion Observation Systems (COSMOS) - Consortium of Universities for Research in Earthquake Engineering

  20. 2016 National Earthquake Conference

    Thank you to our Presenting Sponsor, California Earthquake Authority. What's New? What's Next ? What's Your Role in Building a National Strategy? The National Earthquake Conference (NEC) is a , state government leaders, social science practitioners, U.S. State and Territorial Earthquake Managers

  1. Can We Predict Earthquakes?

    Johnson, Paul

    2018-01-16

    The only thing we know for sure about earthquakes is that one will happen again very soon. Earthquakes pose a vital yet puzzling set of research questions that have confounded scientists for decades, but new ways of looking at seismic information and innovative laboratory experiments are offering tantalizing clues to what triggers earthquakes — and when.

  2. Earthquake and Schools. [Videotape].

    ERIC Educational Resources Information Center

    Federal Emergency Management Agency, Washington, DC.

    Designing schools to make them more earthquake resistant and protect children from the catastrophic collapse of the school building is discussed in this videotape. It reveals that 44 of the 50 U.S. states are vulnerable to earthquake, but most schools are structurally unprepared to take on the stresses that earthquakes exert. The cost to the…

  3. Children's Ideas about Earthquakes

    ERIC Educational Resources Information Center

    Simsek, Canan Lacin

    2007-01-01

    Earthquake, a natural disaster, is among the fundamental problems of many countries. If people know how to protect themselves from earthquake and arrange their life styles in compliance with this, damage they will suffer will reduce to that extent. In particular, a good training regarding earthquake to be received in primary schools is considered…

  4. Operational earthquake forecasting can enhance earthquake preparedness

    Jordan, T.H.; Marzocchi, W.; Michael, A.J.; Gerstenberger, M.C.

    2014-01-01

    We cannot yet predict large earthquakes in the short term with much reliability and skill, but the strong clustering exhibited in seismic sequences tells us that earthquake probabilities are not constant in time; they generally rise and fall over periods of days to years in correlation with nearby seismic activity. Operational earthquake forecasting (OEF) is the dissemination of authoritative information about these time‐dependent probabilities to help communities prepare for potentially destructive earthquakes. The goal of OEF is to inform the decisions that people and organizations must continually make to mitigate seismic risk and prepare for potentially destructive earthquakes on time scales from days to decades. To fulfill this role, OEF must provide a complete description of the seismic hazard—ground‐motion exceedance probabilities as well as short‐term rupture probabilities—in concert with the long‐term forecasts of probabilistic seismic‐hazard analysis (PSHA).

  5. Crowdsourced earthquake early warning

    PubMed Central

    Minson, Sarah E.; Brooks, Benjamin A.; Glennie, Craig L.; Murray, Jessica R.; Langbein, John O.; Owen, Susan E.; Heaton, Thomas H.; Iannucci, Robert A.; Hauser, Darren L.

    2015-01-01

    Earthquake early warning (EEW) can reduce harm to people and infrastructure from earthquakes and tsunamis, but it has not been implemented in most high earthquake-risk regions because of prohibitive cost. Common consumer devices such as smartphones contain low-cost versions of the sensors used in EEW. Although less accurate than scientific-grade instruments, these sensors are globally ubiquitous. Through controlled tests of consumer devices, simulation of an Mw (moment magnitude) 7 earthquake on California’s Hayward fault, and real data from the Mw 9 Tohoku-oki earthquake, we demonstrate that EEW could be achieved via crowdsourcing. PMID:26601167

  6. Crowdsourced earthquake early warning.

    PubMed

    Minson, Sarah E; Brooks, Benjamin A; Glennie, Craig L; Murray, Jessica R; Langbein, John O; Owen, Susan E; Heaton, Thomas H; Iannucci, Robert A; Hauser, Darren L

    2015-04-01

    Earthquake early warning (EEW) can reduce harm to people and infrastructure from earthquakes and tsunamis, but it has not been implemented in most high earthquake-risk regions because of prohibitive cost. Common consumer devices such as smartphones contain low-cost versions of the sensors used in EEW. Although less accurate than scientific-grade instruments, these sensors are globally ubiquitous. Through controlled tests of consumer devices, simulation of an M w (moment magnitude) 7 earthquake on California's Hayward fault, and real data from the M w 9 Tohoku-oki earthquake, we demonstrate that EEW could be achieved via crowdsourcing.

  7. Crowdsourced earthquake early warning

    Minson, Sarah E.; Brooks, Benjamin A.; Glennie, Craig L.; Murray, Jessica R.; Langbein, John O.; Owen, Susan E.; Heaton, Thomas H.; Iannucci, Robert A.; Hauser, Darren L.

    2015-01-01

    Earthquake early warning (EEW) can reduce harm to people and infrastructure from earthquakes and tsunamis, but it has not been implemented in most high earthquake-risk regions because of prohibitive cost. Common consumer devices such as smartphones contain low-cost versions of the sensors used in EEW. Although less accurate than scientific-grade instruments, these sensors are globally ubiquitous. Through controlled tests of consumer devices, simulation of an Mw (moment magnitude) 7 earthquake on California’s Hayward fault, and real data from the Mw 9 Tohoku-oki earthquake, we demonstrate that EEW could be achieved via crowdsourcing.

  8. Earthquake hazards on the cascadia subduction zone.

    PubMed

    Heaton, T H; Hartzell, S H

    1987-04-10

    Large subduction earthquakes on the Cascadia subduction zone pose a potential seismic hazard. Very young oceanic lithosphere (10 million years old) is being subducted beneath North America at a rate of approximately 4 centimeters per year. The Cascadia subduction zone shares many characteristics with subduction zones in southern Chile, southwestern Japan, and Colombia, where comparably young oceanic lithosphere is also subducting. Very large subduction earthquakes, ranging in energy magnitude (M(w)) between 8 and 9.5, have occurred along these other subduction zones. If the Cascadia subduction zone is also storing elastic energy, a sequence of several great earthquakes (M(w) 8) or a giant earthquake (M(w) 9) would be necessary to fill this 1200-kilometer gap. The nature of strong ground motions recorded during subduction earthquakes of M(w) less than 8.2 is discussed. Strong ground motions from even larger earthquakes (M(w) up to 9.5) are estimated by simple simulations. If large subduction earthquakes occur in the Pacific Northwest, relatively strong shaking can be expected over a large region. Such earthquakes may also be accompanied by large local tsunamis.

  9. How fault geometry controls earthquake magnitude

    NASA Astrophysics Data System (ADS)

    Bletery, Q.; Thomas, A.; Karlstrom, L.; Rempel, A. W.; Sladen, A.; De Barros, L.

    2016-12-01

    Recent large megathrust earthquakes, such as the Mw9.3 Sumatra-Andaman earthquake in 2004 and the Mw9.0 Tohoku-Oki earthquake in 2011, astonished the scientific community. The first event occurred in a relatively low-convergence-rate subduction zone where events of its size were unexpected. The second event involved 60 m of shallow slip in a region thought to be aseismicaly creeping and hence incapable of hosting very large magnitude earthquakes. These earthquakes highlight gaps in our understanding of mega-earthquake rupture processes and the factors controlling their global distribution. Here we show that gradients in dip angle exert a primary control on mega-earthquake occurrence. We calculate the curvature along the major subduction zones of the world and show that past mega-earthquakes occurred on flat (low-curvature) interfaces. A simplified analytic model demonstrates that shear strength heterogeneity increases with curvature. Stress loading on flat megathrusts is more homogeneous and hence more likely to be released simultaneously over large areas than on highly-curved faults. Therefore, the absence of asperities on large faults might counter-intuitively be a source of higher hazard.

  10. Triggering of repeating earthquakes in central California

    Wu, Chunquan; Gomberg, Joan; Ben-Naim, Eli; Johnson, Paul

    2014-01-01

    Dynamic stresses carried by transient seismic waves have been found capable of triggering earthquakes instantly in various tectonic settings. Delayed triggering may be even more common, but the mechanisms are not well understood. Catalogs of repeating earthquakes, earthquakes that recur repeatedly at the same location, provide ideal data sets to test the effects of transient dynamic perturbations on the timing of earthquake occurrence. Here we employ a catalog of 165 families containing ~2500 total repeating earthquakes to test whether dynamic perturbations from local, regional, and teleseismic earthquakes change recurrence intervals. The distance to the earthquake generating the perturbing waves is a proxy for the relative potential contributions of static and dynamic deformations, because static deformations decay more rapidly with distance. Clear changes followed the nearby 2004 Mw6 Parkfield earthquake, so we study only repeaters prior to its origin time. We apply a Monte Carlo approach to compare the observed number of shortened recurrence intervals following dynamic perturbations with the distribution of this number estimated for randomized perturbation times. We examine the comparison for a series of dynamic stress peak amplitude and distance thresholds. The results suggest a weak correlation between dynamic perturbations in excess of ~20 kPa and shortened recurrence intervals, for both nearby and remote perturbations.

  11. Characteristics of objective daytime sleep among individuals with earthquake-related posttraumatic stress disorder: A pilot community-based polysomnographic and multiple sleep latency test study.

    PubMed

    Zhang, Yan; Li, Yun; Zhu, Hongru; Cui, Haofei; Qiu, Changjian; Tang, Xiangdong; Zhang, Wei

    2017-01-01

    Little is known about the objective sleep characteristics of patients with posttraumatic stress disorder (PTSD). The present study examines the association between PTSD symptom severity and objective daytime sleep characteristics measured using the Multiple Sleep Latency Test (MSLT) in therapy-naïve patients with earthquake-related PTSD. A total of 23 PTSD patients and 13 trauma-exposed non-PTSD (TEN-PTSD) subjects completed one-night in-lab polysomnography (PSG) followed by a standard MSLT. 8 of the 23 PTSD patients received paroxetine treatment. Compared to the TEN-PTSD subjects, no significant nighttime sleep disturbances were detected by PSG in the subjects with PTSD; however, a shorter mean MSLT value was found in the subjects with PTSD. After adjustment for age, sex, and body mass index, PTSD symptoms, particularly hyperarousal, were found to be independently associated with a shorter MSLT value. Further, the mean MSLT value increased significantly after therapy in PTSD subjects. A shorter MSLT value may be a reliable index of the medical severity of PTSD, while an improvement in MSLT values might also be a reliable marker for evaluating therapeutic efficacy in PTSD patients. Copyright © 2016. Published by Elsevier Ireland Ltd.

  12. Non-double-couple earthquakes. 1. Theory

    Julian, B.R.; Miller, A.D.; Foulger, G.R.

    1998-01-01

    Historically, most quantitative seismological analyses have been based on the assumption that earthquakes are caused by shear faulting, for which the equivalent force system in an isotropic medium is a pair of force couples with no net torque (a 'double couple,' or DC). Observations of increasing quality and coverage, however, now resolve departures from the DC model for many earthquakes and find some earthquakes, especially in volcanic and geothermal areas, that have strongly non-DC mechanisms. Understanding non-DC earthquakes is important both for studying the process of faulting in detail and for identifying nonshear-faulting processes that apparently occur in some earthquakes. This paper summarizes the theory of 'moment tensor' expansions of equivalent-force systems and analyzes many possible physical non-DC earthquake processes. Contrary to long-standing assumption, sources within the Earth can sometimes have net force and torque components, described by first-rank and asymmetric second-rank moment tensors, which must be included in analyses of landslides and some volcanic phenomena. Non-DC processes that lead to conventional (symmetric second-rank) moment tensors include geometrically complex shear faulting, tensile faulting, shear faulting in an anisotropic medium, shear faulting in a heterogeneous region (e.g., near an interface), and polymorphic phase transformations. Undoubtedly, many non-DC earthquake processes remain to be discovered. Progress will be facilitated by experimental studies that use wave amplitudes, amplitude ratios, and complete waveforms in addition to wave polarities and thus avoid arbitrary assumptions such as the absence of volume changes or the temporal similarity of different moment tensor components.

  13. Visualization of bioelectric phenomena.

    PubMed

    Palmer, T C; Simpson, E V; Kavanagh, K M; Smith, W M

    1992-01-01

    Biomedical investigators are currently able to acquire and analyze physiological and anatomical data from three-dimensional structures in the body. Often, multiple kinds of data can be recorded simultaneously. The usefulness of this information, either for exploratory viewing or for presentation to others, is limited by the lack of techniques to display it in intuitive, accessible formats. Unfortunately, the complexity of scientific visualization techniques and the inflexibility of commercial packages deter investigators from using sophisticated visualization methods that could provide them added insight into the mechanisms of the phenomena under study. Also, the sheer volume of such data is a problem. High-performance computing resources are often required for storage and processing, in addition to visualization. This chapter describes a novel, language-based interface that allows scientists with basic programming skills to classify and render multivariate volumetric data with a modest investment in software training. The interface facilitates data exploration by enabling experimentation with various algorithms to compute opacity and color from volumetric data. The value of the system is demonstrated using data from cardiac mapping studies, in which multiple electrodes are placed in an on the heart to measure the cardiac electrical activity intrinsic to the heart and its response to external stimulation.

  14. Arcjet Cathode Phenomena

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Haag, Thomas W.; Raquet, John F.

    1989-01-01

    Cathode tips made from a number of different materials were tested in a modular arcjet thruster in order to examine cathode phenomena. Periodic disassembly and examination, along with the data collected during testing, indicated that all of the tungsten-based materials behaved similarly despite the fact that in one of these samples the percentage of thorium oxide was doubled and another was 25 percent rhenium. The mass loss rate from a 2 percent thoriated rhenium cathode was found to be an order of magnitude greater than that observed using 2 percent thoriated tungsten. Detailed analysis of one of these cathode tips showed that the molten crater contained pure tungsten to a depth of about 150 microns. Problems with thermal stress cracking were encountered in the testing of a hafnium carbide tip. Post test analysis showed that the active area of the tip had chemically reacted with the propellant. A 100 hour continuous test was run at about 1 kW. Post test analysis revealed no dendrite formation, such as observed in a 30 kW arcjet lifetest, near the cathode crater. The cathodes from both this test and a previously run 1000 hour cycled test displayed nearly identical arc craters. Data and calculations indicate that the mass losses observed in testing can be explained by evaporation.

  15. Arcjet cathode phenomena

    NASA Technical Reports Server (NTRS)

    Curran, Francis M.; Haag, Thomas W.; Raquet, John F.

    1989-01-01

    Cathode tips made from a number of different materials were tested in a modular arcjet thruster in order to examine cathode phenomena. Periodic disassembly and examination, along with the data collected during testing, indicated that all of the tungsten-based materials behaved similarly despite the fact that in one of these samples the percentage of thorium oxide was doubled and another was 25 percent rhenium. The mass loss rate from a 2 percent thoriated rhenium cathode was found to be an order of magnitude greater than that observed using 2 percent thoriated tungsten. Detailed analysis of one of these cathode tips showed that the molten crater contained pure tungsten to a depth of about 150 microns. Problems with thermal stress cracking were encountered in the testing of a hafnium carbide tip. Post test analysis showed that the active area of the tip had chemically reacted with the propellant. A 100 hour continuous test was run at about 1 kW. Post test analysis revealed no dendrite formation, such as observed in a 30 kW arcjet lifetest, near the cathode crater. The cathodes from both this test and a previously run 1000 hour cycled test displayed nearly identical arc craters. Data and calculations indicate that the mass losses observed in testing can be explained by evaporation.

  16. 3D geometry of a plate boundary fault related to the 2016 Off-Mie earthquake in the Nankai subduction zone, Japan

    NASA Astrophysics Data System (ADS)

    Tsuji, Takeshi; Minato, Shohei; Kamei, Rie; Tsuru, Tetsuro; Kimura, Gaku

    2017-11-01

    We used recent seismic data and advanced techniques to investigate 3D fault geometry over the transition from the partially coupled to the fully coupled plate interface inboard of the Nankai Trough off the Kii Peninsula, Japan. We found that a gently dipping plate boundary décollement with a thick underthrust layer extends beneath the entire Kumano forearc basin. The 1 April 2016 Off-Mie earthquake (Mw6.0) and its aftershocks occurred, where the plate boundary décollement steps down close to the oceanic crust surface. This location also lies beneath the trenchward edge of an older accretionary prism (∼14 Ma) developed along the coast of the Kii peninsula. The strike of the 2016 rupture plane was similar to that of a formerly active splay fault system in the accretionary prism. Thus, the fault planes of the 2016 earthquake and its aftershocks were influenced by the geometry of the plate interface as well as splay faulting. The 2016 earthquake occurred within the rupture area of large interplate earthquakes such as the 1944 Tonankai earthquake (Mw8.1), although the 2016 rupture area was much smaller than that of the 1944 event. Whereas the hypocenter of the 2016 earthquake was around the underplating sequence beneath the younger accretionary prism (∼6 Ma), the 1944 great earthquake hypocenter was close to oceanic crust surface beneath the older accretionary prism. The variation of fault geometry and lithology may influence the degree of coupling along the plate interface, and such coupling variation could hinder slip propagation toward the deeper plate interface in the 2016 event.

  17. The Ms = 8 tensional earthquake of 9 December 1950 of northern Chile and its relation to the seismic potential of the region

    NASA Astrophysics Data System (ADS)

    Kausel, Edgar; Campos, Jaime

    1992-08-01

    The only known great ( Ms = 8) intermediate depth earthquake localized downdip of the main thrust zone of the Chilean subduction zone occurred landward of Antofagasta on 9 December 1950. In this paper we determine the source parameters and rupture process of this shock by modeling long-period body waves. The source mechanism corresponds to a downdip tensional intraplate event rupturing along a nearly vertical plane with a seismic moment of M0 = 1 × 10 28 dyn cm, of strike 350°, dip 88°, slip 270°, Mw = 7.9 and a stress drop of about 100 bar. The source time function consists of two subevents, the second being responsible for 70% of the total moment release. The unusually large magnitude ( Ms = 8) of this intermediate depth event suggests a rupture through the entire lithosphere. The spatial and temporal stress regime in this region is discussed. The simplest interpretation suggests that a large thrust earthquake should follow the 1950 tensional shock. Considering that the historical record of the region does not show large earthquakes, a 'slow' earthquake can be postulated as an alternative mechanism to unload the thrust zone. A weakly coupled subduction zone—within an otherwise strongly coupled region as evidenced by great earthquakes to the north and south—or the existence of creep are not consistent with the occurrence of a large tensional earthquake in the subducting lithosphere downdip of the thrust zone. The study of focal mechanisms of the outer rise earthquakes would add more information which would help us to infer the present state of stress in the thrust region.

  18. Earthquake Education in Prime Time

    NASA Astrophysics Data System (ADS)

    de Groot, R.; Abbott, P.; Benthien, M.

    2004-12-01

    Since 2001, the Southern California Earthquake Center (SCEC) has collaborated on several video production projects that feature important topics related to earthquake science, engineering, and preparedness. These projects have also fostered many fruitful and sustained partnerships with a variety of organizations that have a stake in hazard education and preparedness. The Seismic Sleuths educational video first appeared in the spring season 2001 on Discovery Channel's Assignment Discovery. Seismic Sleuths is based on a highly successful curriculum package developed jointly by the American Geophysical Union and The Department of Homeland Security Federal Emergency Management Agency. The California Earthquake Authority (CEA) and the Institute for Business and Home Safety supported the video project. Summer Productions, a company with a reputation for quality science programming, produced the Seismic Sleuths program in close partnership with scientists, engineers, and preparedness experts. The program has aired on the National Geographic Channel as recently as Fall 2004. Currently, SCEC is collaborating with Pat Abbott, a geology professor at San Diego State University (SDSU) on the video project Written In Stone: Earthquake Country - Los Angeles. Partners on this project include the California Seismic Safety Commission, SDSU, SCEC, CEA, and the Insurance Information Network of California. This video incorporates live-action demonstrations, vivid animations, and a compelling host (Abbott) to tell the story about earthquakes in the Los Angeles region. The Written in Stone team has also developed a comprehensive educator package that includes the video, maps, lesson plans, and other supporting materials. We will present the process that facilitates the creation of visually effective, factually accurate, and entertaining video programs. We acknowledge the need to have a broad understanding of the literature related to communication, media studies, science education, and

  19. Experimental Study of Thermal Field Evolution in the Short-Impending Stage Before Earthquakes

    NASA Astrophysics Data System (ADS)

    Ren, Yaqiong; Ma, Jin; Liu, Peixun; Chen, Shunyun

    2017-08-01

    Phenomena at critical points are vital for identifying the short-impending stage prior to earthquakes. The peak stress is a critical point when stress is converted from predominantly accumulation to predominantly release. We call the duration between the peak stress and instability "the meta-instability stage", which refers to the short-impending stage of earthquakes. The meta-instability stage consists of a steady releasing quasi-static stage and an accelerated releasing quasi-dynamic stage. The turning point of the above two stages is the remaining critical point. To identify the two critical points in the field, it is necessary to study the characteristic phenomena of various physical fields in the meta-instability stage in the laboratory, and the strain and displacement variations were studied. Considering that stress and relative displacement can be detected by thermal variations and peculiarities in the full-field observations, we employed a cooled thermal infrared imaging system to record thermal variations in the meta-instability stage of stick slip events generated along a simulated, precut planer strike slip fault in a granodiorite block on a horizontally bilateral servo-controlled press machine. The experimental results demonstrate the following: (1) a large area of decreasing temperatures in wall rocks and increasing temperatures in sporadic sections of the fault indicate entrance into the meta-instability stage. (2) The rapid expansion of regions of increasing temperatures on the fault and the enhancement of temperature increase amplitude correspond to the turning point from the quasi-static stage to the quasi-dynamic stage. Our results reveal thermal indicators for the critical points prior to earthquakes that provide clues for identifying the short-impending stage of earthquakes.

  20. Application of τc*Pd in earthquake early warning

    NASA Astrophysics Data System (ADS)

    Huang, Po-Lun; Lin, Ting-Li; Wu, Yih-Min

    2015-03-01

    Rapid assessment of damage potential and size of an earthquake at the station is highly demanded for onsite earthquake early warning. We study the application of τc*Pd for its estimation on the earthquake size using 123 events recorded by the borehole stations of KiK-net in Japan. The new type of earthquake size determined by τc*Pd is more related to the damage potential. We find that τc*Pd provides another parameter to measure the size of earthquake and the threshold to warn strong ground motion.

  1. The effects of earthquake measurement concepts and magnitude anchoring on individuals' perceptions of earthquake risk

    Celsi, R.; Wolfinbarger, M.; Wald, D.

    2005-01-01

    The purpose of this research is to explore earthquake risk perceptions in California. Specifically, we examine the risk beliefs, feelings, and experiences of lay, professional, and expert individuals to explore how risk is perceived and how risk perceptions are formed relative to earthquakes. Our results indicate that individuals tend to perceptually underestimate the degree that earthquake (EQ) events may affect them. This occurs in large part because individuals' personal felt experience of EQ events are generally overestimated relative to experienced magnitudes. An important finding is that individuals engage in a process of "cognitive anchoring" of their felt EQ experience towards the reported earthquake magnitude size. The anchoring effect is moderated by the degree that individuals comprehend EQ magnitude measurement and EQ attenuation. Overall, the results of this research provide us with a deeper understanding of EQ risk perceptions, especially as they relate to individuals' understanding of EQ measurement and attenuation concepts. ?? 2005, Earthquake Engineering Research Institute.

  2. Perspectives on earthquake hazards in the New Madrid seismic zone, Missouri

    Thenhaus, P.C.

    1990-01-01

    A sequence of three great earthquakes struck the Central United States during the winter of 1811-1812 in the area of New Madrid, Missouri. they are considered to be the greatest earthquakes in the conterminous U.S because they were felt and caused damage at far greater distances than any other earthquakes in U.S history. The large population currently living within the damage area of these earthquakes means that widespread destruction and loss of life is likely if the sequence were repeated. In contrast to California, where the earthquakes are felt frequently, the damaging earthquakes that have occurred in the Easter U.S-in 155 (Cape Ann, Mass.), 1811-12 (New Madrid, Mo.), 1886 (Charleston S.C) ,and 1897 (Giles County, Va.- are generally regarded as only historical phenomena (fig. 1). The social memory of these earthquakes no longer exists. A fundamental problem in the Eastern U.S, therefore, is that the earthquake hazard is not generally considered today in land-use and civic planning. This article offers perspectives on the earthquake hazard of the New Madrid seismic zone through discussions of the geology of the Mississippi Embayment, the historical earthquakes that have occurred there, the earthquake risk, and the "tools" that geoscientists have to study the region. The so-called earthquake hazard is defined  by the characterization of the physical attributes of the geological structures that cause earthquakes, the estimation of the recurrence times of the earthquakes, the estimation of the recurrence times of the earthquakes, their potential size, and the expected ground motions. the term "earthquake risk," on the other hand, refers to aspects of the expected damage to manmade strctures and to lifelines as a result of the earthquake hazard.  

  3. Perception of earthquake risk in Taiwan: effects of gender and past earthquake experience.

    PubMed

    Kung, Yi-Wen; Chen, Sue-Huei

    2012-09-01

    This study explored how individuals in Taiwan perceive the risk of earthquake and the relationship of past earthquake experience and gender to risk perception. Participants (n= 1,405), including earthquake survivors and those in the general population without prior direct earthquake exposure, were selected and interviewed through a computer-assisted telephone interviewing procedure using a random sampling and stratification method covering all 24 regions of Taiwan. A factor analysis of the interview data yielded a two-factor structure of risk perception in regard to earthquake. The first factor, "personal impact," encompassed perception of threat and fear related to earthquakes. The second factor, "controllability," encompassed a sense of efficacy of self-protection in regard to earthquakes. The findings indicated prior earthquake survivors and females reported higher scores on the personal impact factor than males and those with no prior direct earthquake experience, although there were no group differences on the controllability factor. The findings support that risk perception has multiple components, and suggest that past experience (survivor status) and gender (female) affect the perception of risk. Exploration of potential contributions of other demographic factors such as age, education, and marital status to personal impact, especially for females and survivors, is discussed. Future research on and intervention program with regard to risk perception are suggested accordingly. © 2012 Society for Risk Analysis.

  4. Impact of earthquakes on sex ratio at birth: Eastern Marmara earthquakes

    PubMed Central

    Doğer, Emek; Çakıroğlu, Yiğit; Köpük, Şule Yıldırım; Ceylan, Yasin; Şimşek, Hayal Uzelli; Çalışkan, Eray

    2013-01-01

    Objective: Previous reports suggest that maternal exposure to acute stress related to earthquakes affects the sex ratio at birth. Our aim was to examine the change in sex ratio at birth after Eastern Marmara earthquake disasters. Material and Methods: This study was performed using the official birth statistics from January 1997 to December 2002 – before and after 17 August 1999, the date of the Golcuk Earthquake – supplied from the Turkey Statistics Institute. The secondary sex ratio was expressed as the male proportion at birth, and the ratio of both affected and unaffected areas were calculated and compared on a monthly basis using data from gender with using the Chi-square test. Results: We observed significant decreases in the secondary sex ratio in the 4th and 8th months following an earthquake in the affected region compared to the unaffected region (p= 0.001 and p= 0.024). In the earthquake region, the decrease observed in the secondary sex ratio during the 8th month after an earthquake was specific to the period after the earthquake. Conclusion: Our study indicated a significant reduction in the secondary sex ratio after an earthquake. With these findings, events that cause sudden intense stress such as earthquakes can have an effect on the sex ratio at birth. PMID:24592082

  5. Japanese earthquake predictability experiment with multiple runs before and after the 2011 Tohoku-oki earthquake

    NASA Astrophysics Data System (ADS)

    Hirata, N.; Tsuruoka, H.; Yokoi, S.

    2011-12-01

    The current Japanese national earthquake prediction program emphasizes the importance of modeling as well as monitoring for a sound scientific development of earthquake prediction research. One major focus of the current program is to move toward creating testable earthquake forecast models. For this purpose, in 2009 we joined the Collaboratory for the Study of Earthquake Predictability (CSEP) and installed, through an international collaboration, the CSEP Testing Centre, an infrastructure to encourage researchers to develop testable models for Japan. We started Japanese earthquake predictability experiment on November 1, 2009. The experiment consists of 12 categories, with 4 testing classes with different time spans (1 day, 3 months, 1 year and 3 years) and 3 testing regions called 'All Japan,' 'Mainland,' and 'Kanto.' A total of 160 models, as of August 2013, were submitted, and are currently under the CSEP official suite of tests for evaluating the performance of forecasts. We will present results of prospective forecast and testing for periods before and after the 2011 Tohoku-oki earthquake. Because a seismic activity has changed dramatically since the 2011 event, performances of models have been affected very much. In addition, as there is the problem of authorized catalogue related to the completeness magnitude, most models did not pass the CSEP consistency tests. Also, we will discuss the retrospective earthquake forecast experiments for aftershocks of the 2011 Tohoku-oki earthquake. Our aim is to describe what has turned out to be the first occasion for setting up a research environment for rigorous earthquake forecasting in Japan.

  6. Japanese earthquake predictability experiment with multiple runs before and after the 2011 Tohoku-oki earthquake

    NASA Astrophysics Data System (ADS)

    Hirata, N.; Tsuruoka, H.; Yokoi, S.

    2013-12-01

    The current Japanese national earthquake prediction program emphasizes the importance of modeling as well as monitoring for a sound scientific development of earthquake prediction research. One major focus of the current program is to move toward creating testable earthquake forecast models. For this purpose, in 2009 we joined the Collaboratory for the Study of Earthquake Predictability (CSEP) and installed, through an international collaboration, the CSEP Testing Centre, an infrastructure to encourage researchers to develop testable models for Japan. We started Japanese earthquake predictability experiment on November 1, 2009. The experiment consists of 12 categories, with 4 testing classes with different time spans (1 day, 3 months, 1 year and 3 years) and 3 testing regions called 'All Japan,' 'Mainland,' and 'Kanto.' A total of 160 models, as of August 2013, were submitted, and are currently under the CSEP official suite of tests for evaluating the performance of forecasts. We will present results of prospective forecast and testing for periods before and after the 2011 Tohoku-oki earthquake. Because a seismic activity has changed dramatically since the 2011 event, performances of models have been affected very much. In addition, as there is the problem of authorized catalogue related to the completeness magnitude, most models did not pass the CSEP consistency tests. Also, we will discuss the retrospective earthquake forecast experiments for aftershocks of the 2011 Tohoku-oki earthquake. Our aim is to describe what has turned out to be the first occasion for setting up a research environment for rigorous earthquake forecasting in Japan.

  7. Transport phenomena in environmental engineering

    NASA Astrophysics Data System (ADS)

    Sander, Aleksandra; Kardum, Jasna Prlić; Matijašić, Gordana; Žižek, Krunoslav

    2018-01-01

    A term transport phenomena arises as a second paradigm at the end of 1950s with high awareness that there was a strong need to improve the scoping of chemical engineering science. At that point, engineers became highly aware that it is extremely important to take step forward from pure empirical description and the concept of unit operations only to understand the specific process using phenomenological equations that rely on three elementary physical processes: momentum, energy and mass transport. This conceptual evolution of chemical engineering was first presented with a well-known book of R. Byron Bird, Warren E. Stewart and Edwin N. Lightfoot, Transport Phenomena, published in 1960 [1]. What transport phenomena are included in environmental engineering? It is hard to divide those phenomena through different engineering disciplines. The core is the same but the focus changes. Intention of the authors here is to present the transport phenomena that are omnipresent in treatment of various process streams. The focus in this chapter is made on the transport phenomena that permanently occur in mechanical macroprocesses of sedimentation and filtration for separation in solid-liquid particulate systems and on the phenomena of the flow through a fixed and a fluidized bed of particles that are immanent in separation processes in packed columns and in environmental catalysis. The fundamental phenomena for each thermal and equilibrium separation process technology are presented as well. Understanding and mathematical description of underlying transport phenomena result in scoping the separation processes in a way that ChEs should act worldwide.

  8. Defining "Acceptable Risk" for Earthquakes Worldwide

    NASA Astrophysics Data System (ADS)

    Tucker, B.

    2001-05-01

    The greatest and most rapidly growing earthquake risk for mortality is in developing countries. Further, earthquake risk management actions of the last 50 years have reduced the average lethality of earthquakes in earthquake-threatened industrialized countries. (This is separate from the trend of the increasing fiscal cost of earthquakes there.) Despite these clear trends, every new earthquake in developing countries is described in the media as a "wake up" call, announcing the risk these countries face. GeoHazards International (GHI) works at both the community and the policy levels to try to reduce earthquake risk. GHI reduces death and injury by helping vulnerable communities recognize their risk and the methods to manage it, by raising awareness of its risk, building local institutions to manage that risk, and strengthening schools to protect and train the community's future generations. At the policy level, GHI, in collaboration with research partners, is examining whether "acceptance" of these large risks by people in these countries and by international aid and development organizations explains the lack of activity in reducing these risks. The goal of this pilot project - The Global Earthquake Safety Initiative (GESI) - is to develop and evaluate a means of measuring the risk and the effectiveness of risk mitigation actions in the world's largest, most vulnerable cities: in short, to develop an earthquake risk index. One application of this index is to compare the risk and the risk mitigation effort of "comparable" cities. By this means, Lima, for example, can compare the risk of its citizens dying due to earthquakes with the risk of citizens in Santiago and Guayaquil. The authorities of Delhi and Islamabad can compare the relative risk from earthquakes of their school children. This index can be used to measure the effectiveness of alternate mitigation projects, to set goals for mitigation projects, and to plot progress meeting those goals. The preliminary

  9. Catalog of Hawaiian earthquakes, 1823-1959

    Klein, Fred W.; Wright, Thomas L.

    2000-01-01

    This catalog of more than 17,000 Hawaiian earthquakes (of magnitude greater than or equal to 5), principally located on the Island of Hawaii, from 1823 through the third quarter of 1959 is designed to expand our ability to evaluate seismic hazard in Hawaii, as well as our knowledge of Hawaiian seismic rhythms as they relate to eruption cycles at Kilauea and Mauna Loa volcanoes and to subcrustal earthquake patterns related to the tectonic evolution of the Hawaiian chain.

  10. Missing great earthquakes

    Hough, Susan E.

    2013-01-01

    The occurrence of three earthquakes with moment magnitude (Mw) greater than 8.8 and six earthquakes larger than Mw 8.5, since 2004, has raised interest in the long-term global rate of great earthquakes. Past studies have focused on the analysis of earthquakes since 1900, which roughly marks the start of the instrumental era in seismology. Before this time, the catalog is less complete and magnitude estimates are more uncertain. Yet substantial information is available for earthquakes before 1900, and the catalog of historical events is being used increasingly to improve hazard assessment. Here I consider the catalog of historical earthquakes and show that approximately half of all Mw ≥ 8.5 earthquakes are likely missing or underestimated in the 19th century. I further present a reconsideration of the felt effects of the 8 February 1843, Lesser Antilles earthquake, including a first thorough assessment of felt reports from the United States, and show it is an example of a known historical earthquake that was significantly larger than initially estimated. The results suggest that incorporation of best available catalogs of historical earthquakes will likely lead to a significant underestimation of seismic hazard and/or the maximum possible magnitude in many regions, including parts of the Caribbean.

  11. A local earthquake coda magnitude and its relation to duration, moment M sub O, and local Richter magnitude M sub L

    NASA Technical Reports Server (NTRS)

    Suteau, A. M.; Whitcomb, J. H.

    1977-01-01

    A relationship was found between the seismic moment, M sub O, of shallow local earthquakes and the total duration of the signal, t, in seconds, measured from the earthquakes origin time, assuming that the end of the coda is composed of backscattering surface waves due to lateral heterogenity in the shallow crust following Aki. Using the linear relationship between the logarithm of M sub O and the local Richter magnitude M sub L, a relationship between M sub L and t, was found. This relationship was used to calculate a coda magnitude M sub C which was compared to M sub L for Southern California earthquakes which occurred during the period from 1972 to 1975.

  12. Retrospective stress-forecasting of earthquakes

    NASA Astrophysics Data System (ADS)

    Gao, Yuan; Crampin, Stuart

    2015-04-01

    retrospectively stress-forecasting ~17 earthquakes ranging in magnitude from a M1.7 swarm event in N Iceland, to the 1999 M7.7 Chi-Chi Earthquake in Taiwan, and the 2004 Mw9.2 Sumatra-Andaman Earthquake (SAE). Before SAE, the changes in SWS were observed at seismic stations in Iceland at a distance of ~10,500km the width of the Eurasian Plate, from Indonesia demonstrating the 'butterfly wings' sensitivity of the New Geophysics of a critically microcracked Earth. At that time, the sensitivity of the phenomena had not been recognised, and the SAE was not stress-forecast. These results have been published at various times in various formats in various journals. This presentation displays all the results in a normalised format that allows the similarities to be recognised, confirming that observations of SWS time-delays can stress-forecast the times, magnitudes, and in some circumstances fault-breaks, of impending earthquakes. Papers referring to these developments can be found in geos.ed.ac.uk/home/scrampin/opinion. Also see abstracts in EGU2015 Sessions: Crampin & Gao (SM1.1), Liu & Crampin (NH2.5), and Crampin & Gao (GD.1).

  13. Prototype operational earthquake prediction system

    Spall, Henry

    1986-01-01

    An objective if the U.S. Earthquake Hazards Reduction Act of 1977 is to introduce into all regions of the country that are subject to large and moderate earthquakes, systems for predicting earthquakes and assessing earthquake risk. In 1985, the USGS developed for the Secretary of the Interior a program for implementation of a prototype operational earthquake prediction system in southern California.

  14. Simulations of Biomechanical Phenomena

    NASA Astrophysics Data System (ADS)

    Gonzalez, Jose Cruz

    Recent studies have published breakthroughs in the application of finite element (FEA) studies in the design and analysis of advanced orthodontics. However, FEA has not captured bone remodeling responses to advanced orthodontics. The results of these simulations report unrealistic displacement around the nasal bridge, which impeded correlation with clinical data. Bone remodeling has been previously documented in FEA and has shown bone response to mechanical stimulus in femur bone models. However, the relationship between mechanical stimulus and bone remodeling has not been reported in orthodontic studies due to the complexity of the skull. In the current study, strain energy is used as the mechanical stimulus to control remodeling, from which density and modulus evolve. Due to the localization of forces in orthodontics, current remodeling algorithms have limited application. In turn, we developed an algorithm that dynamically collects, sorts, and bins stresses in all elements for regional remodeling based on the proximity of the element to the load. The results demonstrate that bone response to orthodontic appliances is different than that of an FEA without bone remodeling, due to load path changes based upon evolution of the bone properties. It was also found that density and moduli proximal to the load application site exhibit faster remodeling than those located remotely. Modeling another biomechanical phenomena, a 3D simulation was created to simulate recent experimental results that discovered a difference in impact mitigation properties of dense-polymer/foam bilayer structure based on the orientation of the dense-polymer with respect to the impact site. The impact energy transmitted varied in time of arrival and amplitude depending on the orientation of the structure (thin layer up or down). By creating a 3D explicit dynamic FEA simulation, it is expected to reduce costly experiments and time consumed in set up, and offer opportunities for optimization for

  15. Detection of moisture and moisture related phenomena from Skylab. [correlation of brightness and antenna temperature with soil moisture for Texas and Kansas test sites

    NASA Technical Reports Server (NTRS)

    Eagleman, J. R.; Pogge, E. C.; Moore, R. K. (Principal Investigator); Hardy, N.; Lin, W.; League, L.

    1974-01-01

    The author has identified the following significant results. Skylab 2 data for June 5, 1973 (Texas site) relates favorably with previously calculated aircraft data when correlating brightness temperature to soil moisture. However, more detailed work is needed to determine the corrected surface temperature. In addition, correlations between the S194 antenna temperature and soil moisture have been obtained for five sets of Skylab data. The best correlations were obtained for the surface to one inch depth in four cases and for surface to two inches depth for the fifth case. Correlation coefficients for the surface to one inch depth were -0.98, -0.95, -0.90, -0.82, and -0.80.

  16. Effects of layered crust on the coseismic slip inversion and related CFF variations: Hints from the 2012 Emilia Romagna earthquake

    NASA Astrophysics Data System (ADS)

    Nespoli, Massimo; Belardinelli, Maria E.; Anderlini, Letizia; Bonafede, Maurizio; Pezzo, Giuseppe; Todesco, Micol; Rinaldi, Antonio P.

    2017-12-01

    The 2012 Emilia Romagna (Italy) seismic sequence has been extensively studied given the occurrence of two mainshocks, both temporally and spatially close to each other. The recent literature accounts for several fault models, obtained with different inversion methods and different datasets. Several authors investigated the possibility that the second event was triggered by the first mainshock with elusive results. In this work, we consider all the available InSAR and GPS datasets and two planar fault geometries, which are based on both seismological and geological constraints. We account for a layered, elastic half-space hosting the dislocation and compare the slip distribution resulting from the inversion and the related changes in Coulomb Failure Function (CFF) obtained with both a homogeneous and layered half-space. Finally, we focus on the interaction between the two main events, discriminating the contributions of coseismic and early postseismic slip of the mainshock on the generation of the second event and discuss the spatio-temporal distribution of the seismic sequence. When accounting for both InSAR and GPS geodetic data we are able to reproduce a detailed coseismic slip distribution for the two mainshocks that is in accordance with the overall aftershock seismicity distribution. Furthermore, we see that an elastic medium with depth dependent rigidity better accounts for the lack of the shallow seismicity, amplifying, with respect to the homogeneous case, the mechanical interaction of the two mainshocks.

  17. NRIAG's Effort to Mitigate Earthquake Disasters in Egypt Using GPS and Seismic Data

    NASA Astrophysics Data System (ADS)

    Mahmoud, Salah

    It has been estimated that, during historical time more than 50 million people have lost their lives in earthquakes during ground shaking, such as soil amplification and/or liquefaction, landslides and tsunamis or its immediate aftereffects, as fires. The distribution of population takes generally no account of earthquake risk, at least on a large scale. An earthquake may be large but not destructive, on the other hand, an earthquake may be destructive but not large. The absence of correlation is due to the fact that, great number of other factors entering into consideration: first of all, the location of the earthquake in relation to populated areas, also soil conditions and building constructions. Soil liquefaction has been identified as the underlying phenomenon for many ground failures, settlements and lateral spreads, which are a major cause of damage to soil structures and building foundations in many events. Egypt is suffered a numerous of destructive earthquakes as well as Kalabsha earthquake (1981, Mag 5.4) near Aswan city and the High dam, Dahshour earthquake (1992, Mag 5.9) near Cairo city and Aqaba earthquake (1995, Mag 7.2). As the category of earthquake damage includes all the phenomena related to the direct and indirect damages, the Egyptian authorities do a great effort to mitigate the earthquake disasters. The seismicity especially at the zones of high activity is investigated in details in order to obtain the active source zones not only by the Egyptian National Seismic Network (ENSN) but also by the local seismic networks at, Aswan, Hurghada, Aqaba, Abu Dabbab and Dabbaa. On the other hand the soil condition, soil amplification, soil structure interaction, liquefaction and seismic hazard are carried out in particular the urbanized areas and the region near the source zones. All these parameters are integrated to obtain the Egyptian building code which is valid to construct buildings resist damages and consequently mitigate the earthquake

  18. The 2012 Mw5.6 earthquake in Sofia seismogenic zone - is it a slow earthquake

    NASA Astrophysics Data System (ADS)

    Raykova, Plamena; Solakov, Dimcho; Slavcheva, Krasimira; Simeonova, Stela; Aleksandrova, Irena

    2017-04-01

    Recently our understanding of tectonic faulting has been shaken by the discoveries of seismic tremor, low frequency earthquakes, slow slip events, and other models of fault slip. These phenomenas represent models of failure that were thought to be non-existent and theoretically impossible only a few years ago. Slow earthquakes are seismic phenomena in which the rupture of geological faults in the earth's crust occurs gradually without creating strong tremors. Despite the growing number of observations of slow earthquakes their origin remains unresolved. Studies show that the duration of slow earthquakes ranges from a few seconds to a few hundred seconds. The regular earthquakes with which most people are familiar release a burst of built-up stress in seconds, slow earthquakes release energy in ways that do little damage. This study focus on the characteristics of the Mw5.6 earthquake occurred in Sofia seismic zone on May 22nd, 2012. The Sofia area is the most populated, industrial and cultural region of Bulgaria that faces considerable earthquake risk. The Sofia seismic zone is located in South-western Bulgaria - the area with pronounce tectonic activity and proved crustal movement. In 19th century the city of Sofia (situated in the centre of the Sofia seismic zone) has experienced two strong earthquakes with epicentral intensity of 10 MSK. During the 20th century the strongest event occurred in the vicinity of the city of Sofia is the 1917 earthquake with MS=5.3 (I0=7-8 MSK64).The 2012 quake occurs in an area characterized by a long quiescence (of 95 years) for moderate events. Moreover, a reduced number of small earthquakes have also been registered in the recent past. The Mw5.6 earthquake is largely felt on the territory of Bulgaria and neighbouring countries. No casualties and severe injuries have been reported. Mostly moderate damages were observed in the cities of Pernik and Sofia and their surroundings. These observations could be assumed indicative for a

  19. Some Phenomena on Negative Inversion Constructions

    ERIC Educational Resources Information Center

    Sung, Tae-Soo

    2013-01-01

    We examine the characteristics of NDI (negative degree inversion) and its relation with other inversion phenomena such as SVI (subject-verb inversion) and SAI (subject-auxiliary inversion). The negative element in the NDI construction may be" not," a negative adverbial, or a negative verb. In this respect, NDI has similar licensing…

  20. The making of extraordinary psychological phenomena.

    PubMed

    Lamont, Peter

    2012-01-01

    This article considers the extraordinary phenomena that have been central to unorthodox areas of psychological knowledge. It shows how even the agreed facts relating to mesmerism, spiritualism, psychical research, and parapsychology have been framed as evidence both for and against the reality of the phenomena. It argues that these disputes can be seen as a means through which beliefs have been formulated and maintained in the face of potentially challenging evidence. It also shows how these disputes appealed to different forms of expertise, and that both sides appealed to belief in various ways as part of the ongoing dispute about both the facts and expertise. Finally, it shows how, when a formal Psychology of paranormal belief emerged in the twentieth century, it took two different forms, each reflecting one side of the ongoing dispute about the reality of the phenomena. © 2012 Wiley Periodicals, Inc.

  1. [Neural activity related to emotional and empathic deficits in subjects with post-traumatic stress disorder who survived the L'Aquila (Central Italy) 2009 earthquake].

    PubMed

    Mazza, Monica; Pino, Maria Chiara; Tempesta, Daniela; Catalucci, Alessia; Masciocchi, Carlo; Ferrara, Michele

    2016-01-01

    Post-Traumatic Stress Disorder (PTSD) is a chronic anxiety disorder. The continued efforts to control the distressing memories by traumatized individuals, together with the reduction of responsiveness to the outside world, are called Emotional Numbing (EN). The EN is one of the central symptoms in PTSD and it plays an integral role not only in the development and maintenance of post-traumatic symptomatology, but also in the disability of emotional regulation. This disorder shows an abnormal response of cortical and limbic regions which are normally involved in understanding emotions since the very earliest stages of the development of processing ability. Patients with PTSD exhibit exaggerated brain responses to emotionally negative stimuli. Identifying the neural correlates of emotion regulation in these subjects is important for elucidating the neural circuitry involved in emotional and empathic dysfunction. We showed that PTSD patients, all survivors of the L'Aquila 2009 earthquake, have a higher sensitivity to negative emotion and lower empathy levels. These emotional and empathic deficits are accompanied by neural brain functional correlates. Indeed PTSD subjects exhibit functional abnormalities in brain regions that are involved in stress regulation and emotional responses. The reduced activation of the frontal areas and a stronger activation of the limbic areas when responding to emotional stimuli could lead the subjects to enact coping strategies aimed at protecting themselves from the re-experience of pain related to traumatic events. This would result in a dysfunctional hyperactivation of subcortical areas, which may cause emotional distress and, consequently, impaired social relationships often reported by PTSD patients.

  2. Joint Inversion of 1-Hz GPS Data and Strong Motion Records for the Rupture Process of the 2008 Iwate-Miyagi Nairiku Earthquake: Objectively Determining Relative Weighting

    NASA Astrophysics Data System (ADS)

    Wang, Z.; Kato, T.; Wang, Y.

    2015-12-01

    The spatiotemporal fault slip history of the 2008 Iwate-Miyagi Nairiku earthquake, Japan, is obtained by the joint inversion of 1-Hz GPS waveforms and near-field strong motion records. 1-Hz GPS data from GEONET is processed by GAMIT/GLOBK and then a low-pass filter of 0.05 Hz is applied. The ground surface strong motion records from stations of K-NET and Kik-Net are band-pass filtered for the range of 0.05 ~ 0.3 Hz and integrated once to obtain velocity. The joint inversion exploits a broader frequency band for near-field ground motions, which provides excellent constraints for both the detailed slip history and slip distribution. A fully Bayesian inversion method is performed to simultaneously and objectively determine the rupture model, the unknown relative weighting of multiple data sets and the unknown smoothing hyperparameters. The preferred rupture model is stable for different choices of velocity structure model and station distribution, with maximum slip of ~ 8.0 m and seismic moment of 2.9 × 1019 Nm (Mw 6.9). By comparison with the single inversion of strong motion records, the cumulative slip distribution of joint inversion shows sparser slip distribution with two slip asperities. One common slip asperity extends from the hypocenter southeastward to the ground surface of breakage; another slip asperity, which is unique for joint inversion contributed by 1-Hz GPS waveforms, appears in the deep part of fault where very few aftershocks are occurring. The differential moment rate function of joint and single inversions obviously indicates that rich high frequency waves are radiated in the first three seconds but few low frequency waves.

  3. The Advanced Rapid Imaging and Analysis (ARIA) Project: Status of SAR products for Earthquakes, Floods, Volcanoes and Groundwater-related Subsidence

    NASA Astrophysics Data System (ADS)

    Owen, S. E.; Yun, S. H.; Hua, H.; Agram, P. S.; Liu, Z.; Sacco, G. F.; Manipon, G.; Linick, J. P.; Fielding, E. J.; Lundgren, P.; Farr, T. G.; Webb, F.; Rosen, P. A.; Simons, M.

    2017-12-01

    The Advanced Rapid Imaging and Analysis (ARIA) project for Natural Hazards is focused on rapidly generating high-level geodetic imaging products and placing them in the hands of the solid earth science and local, national, and international natural hazard communities by providing science product generation, exploration, and delivery capabilities at an operational level. Space-based geodetic measurement techniques including Interferometric Synthetic Aperture Radar (InSAR), differential Global Positioning System, and SAR-based change detection have become critical additions to our toolset for understanding and mapping the damage and deformation caused by earthquakes, volcanic eruptions, floods, landslides, and groundwater extraction. Up until recently, processing of these data sets has been handcrafted for each study or event and has not generated products rapidly and reliably enough for response to natural disasters or for timely analysis of large data sets. The ARIA project, a joint venture co-sponsored by the California Institute of Technology and by NASA through the Jet Propulsion Laboratory, has been capturing the knowledge applied to these responses and building it into an automated infrastructure to generate imaging products in near real-time that can improve situational awareness for disaster response. In addition to supporting the growing science and hazard response communities, the ARIA project has developed the capabilities to provide automated imaging and analysis capabilities necessary to keep up with the influx of raw SAR data from geodetic imaging missions such as ESA's Sentinel-1A/B, now operating with repeat intervals as short as 6 days, and the upcoming NASA NISAR mission. We will present the progress and results we have made on automating the analysis of Sentinel-1A/B SAR data for hazard monitoring and response, with emphasis on recent developments and end user engagement in flood extent mapping and deformation time series for both volcano

  4. Testing hypotheses of earthquake occurrence

    NASA Astrophysics Data System (ADS)

    Kagan, Y. Y.; Jackson, D. D.; Schorlemmer, D.; Gerstenberger, M.

    2003-12-01

    We present a relatively straightforward likelihood method for testing those earthquake hypotheses that can be stated as vectors of earthquake rate density in defined bins of area, magnitude, and time. We illustrate the method as it will be applied to the Regional Earthquake Likelihood Models (RELM) project of the Southern California Earthquake Center (SCEC). Several earthquake forecast models are being developed as part of this project, and additional contributed forecasts are welcome. Various models are based on fault geometry and slip rates, seismicity, geodetic strain, and stress interactions. We would test models in pairs, requiring that both forecasts in a pair be defined over the same set of bins. Thus we offer a standard "menu" of bins and ground rules to encourage standardization. One menu category includes five-year forecasts of magnitude 5.0 and larger. Forecasts would be in the form of a vector of yearly earthquake rates on a 0.05 degree grid at the beginning of the test. Focal mechanism forecasts, when available, would be also be archived and used in the tests. The five-year forecast category may be appropriate for testing hypotheses of stress shadows from large earthquakes. Interim progress will be evaluated yearly, but final conclusions would be made on the basis of cumulative five-year performance. The second category includes forecasts of earthquakes above magnitude 4.0 on a 0.05 degree grid, evaluated and renewed daily. Final evaluation would be based on cumulative performance over five years. Other types of forecasts with different magnitude, space, and time sampling are welcome and will be tested against other models with shared characteristics. All earthquakes would be counted, and no attempt made to separate foreshocks, main shocks, and aftershocks. Earthquakes would be considered as point sources located at the hypocenter. For each pair of forecasts, we plan to compute alpha, the probability that the first would be wrongly rejected in favor of

  5. Hydro-Mechanical Modelling of Slow Slip Phenomena at the Subduction Interface.

    NASA Astrophysics Data System (ADS)

    Petrini, C.; Gerya, T.; Madonna, C.; van Dinther, Y.

    2016-12-01

    Subduction zones experience a spectrum of slip phenomena, ranging from large devastating megathrust earthquakes to aseismic slow slip events. Slow slip events, lasting hours to years and being perceptible only by instruments, are believed to have the capability to induce large earthquakes. It is also repeatedly proposed that such slow events are controlled by fluid-rock interactions along the subduction interface, thus calling for development of fully coupled seismo-hydro-mechanical modeling approaches to identify their physics and controlling parameters. We present a newly developed finite difference visco-elasto-plastic numerical code with marker-in-cell technique, which fully couples mechanical deformation and fluid flow. We use this to investigate how the presence of fluids in the pore space of a (de)compacting rock matrix affects elastic stress accumulation and release along a fluid-bearing subduction interface. The model simulates the spontaneous occurrence of quasi-periodic slow slip phenomena along self-consistently forming highly localized shearbands, which accommodate shear displacement between two plates. The produced elastic rebound events show a slip velocity on the order of cm/yr, which is in good agreement with measured data. The governing gradual strength decrease along the slowly propagating shear bands is related to a drop in total pressure caused by shear localization at nearly constant (slightly decreasing) fluid pressure. Gradual reduction of the difference between the total and fluid pressure decreases brittle/plastic strength of fluid-bearing rocks along the shear bands, thus providing a dynamic feedback mechanism for the accumulated elastic stress release at the subduction interface.

  6. GPS detection of ionospheric perturbation before the 13 February 2001, El Salvador earthquake

    NASA Astrophysics Data System (ADS)

    Plotkin, V. V.

    A large earthquake of M6.6 occurred on 13 February 2001 at 14:22:05 UT in El Salvador. We detected ionospheric perturbation before this earthquake using GPS data received from CORS network. Systematic decreases of ionospheric total electron content during two days before the earthquake onset were observed at set of stations near the earthquake location and probably in region of about 1000 km from epicenter. This result is consistent with that of investigators, which studied these phenomena with several observational techniques. However it is possible, that such TEC changes are simultaneously accompanied by changes due to solar wind parameters and Kp -index.

  7. Earthquakes in Alaska

    Haeussler, Peter J.; Plafker, George

    1995-01-01

    Earthquake risk is high in much of the southern half of Alaska, but it is not the same everywhere. This map shows the overall geologic setting in Alaska that produces earthquakes. The Pacific plate (darker blue) is sliding northwestward past southeastern Alaska and then dives beneath the North American plate (light blue, green, and brown) in southern Alaska, the Alaska Peninsula, and the Aleutian Islands. Most earthquakes are produced where these two plates come into contact and slide past each other. Major earthquakes also occur throughout much of interior Alaska as a result of collision of a piece of crust with the southern margin.

  8. Earthquakes, November-December 1973

    Person, W.J.

    1974-01-01

    Other parts of the world suffered fatalities and significant damage from earthquakes. In Iran, an earthquake killed one person, injured many, and destroyed a number of homes. Earthquake fatalities also occurred in the Azores and in Algeria. 

  9. Investigation of atmospheric anomalies associated with Kashmir and Awaran Earthquakes

    NASA Astrophysics Data System (ADS)

    Mahmood, Irfan; Iqbal, Muhammad Farooq; Shahzad, Muhammad Imran; Qaiser, Saddam

    2017-02-01

    The earthquake precursors' anomalies at diverse elevation ranges over the seismogenic region and prior to the seismic events are perceived using Satellite Remote Sensing (SRS) techniques and reanalysis datasets. In the current research, seismic precursors are obtained by analyzing anomalies in Outgoing Longwave Radiation (OLR), Air Temperature (AT), and Relative Humidity (RH) before the two strong Mw>7 earthquakes in Pakistan occurred on 8th October 2005 in Azad Jammu Kashmir with Mw 7.6, and 24th September 2013 in Awaran, Balochistan with Mw 7.7. Multi-parameter data were computed based on multi-year background data for anomalies computation. Results indicate significant transient variations in observed parameters before the main event. Detailed analysis suggests presence of pre-seismic activities one to three weeks prior to the main earthquake event that vanishes after the event. These anomalies are due to increase in temperature after release of gases and physical and chemical interactions on earth surface before the earthquake. The parameter variations behavior for both Kashmir and Awaran earthquake events are similar to other earthquakes in different regions of the world. This study suggests that energy release is not concentrated to a single fault but instead is released along the fault zone. The influence of earthquake events on lightning were also investigated and it was concluded that there is a significant atmospheric lightning activity after the earthquake suggesting a strong possibility for an earthquake induced thunderstorm. This study is valuable for identifying earthquake precursors especially in earthquake prone areas.

  10. Review of Natural Phenomena Hazard (NPH) Assessments for the Hanford 200 Areas (Non-Seismic)

    SciT

    Snow, Robert L.; Ross, Steven B.; Sullivan, Robin S.

    2010-09-24

    The purpose of this review is to assess the need for updating Natural Phenomena Hazard (NPH) assessments for the Hanford 200 Areas, as required by DOE Order 420.1B Chapter IV, Natural Phenomena Hazards Mitigation, based on significant changes in state-of-the-art NPH assessment methodology or site-specific information. The review includes all natural phenomena hazards with the exception of seismic/earthquake hazards, which are being addressed under a separate effort. It was determined that existing non-seismic NPH assessments are consistent with current design methodology and site specific data.

  11. Gravity drives Great Earthquakes

    NASA Astrophysics Data System (ADS)

    Lister, Gordon; Forster, Marnie

    2010-05-01

    The most violent of Great Earthquakes are driven by ruptures on giant megathrusts adjacent to actively forming mountain belts. Current theory suggests that the seismic rupture harvests (and thus releases) elastic energy that has been previously stored in locked segments of the megathrust. The general belief, however, is that this energy was accumulated as the result of relative motion of the adjacent stiff elastic tectonic plates. This mechanism fails to explain many first order aspects of large earthquakes, however. The energy source for strain accumulation must also include gravitational collapse of orogenic crust and/or in the foundering (or roll-back) of an adjacent subducting lithospheric slab. Therefore we have conducted an analysis of the geometry of aftershocks, and report that this allows distinction of two types of failure on giant megathrusts. Mode I failure involves horizontal shortening, and is consistent with the classic view that megathrusts fail in compression, with motion analogous to that expected if accretion takes place against a rigid (or elastic) backstop. Mode II failure involves horizontal extension, and requires the over-riding plate to stretch during an earthquake. This process is likely to continue during the subsequent period of afterslip, and therefore will again be evident in aftershock patterns. Mode I behaviour may well have applied to the southern segment of the Sumatran megathrust, from whence emanated the rupture that drove the 2004 Great Earthquake. Mode II behaviour appears to apply to the northern segment of the same rupture, however. The geometry of aftershocks beneath the Andaman Sea suggest that the crust above the initial rupture failed in an extensional mode. The edge of the Indian plate is foundering, with slab-hinge roll-back in a direction orthogonal to its motion vector. The only possible cause for this extension therefore is westward roll-back of the subducting Indian plate, and the consequent gravity-driven movement

  12. Frog Swarms: Earthquake Precursors or False Alarms?

    PubMed Central

    Grant, Rachel A.; Conlan, Hilary

    2013-01-01

    Simple Summary Media reports linking unusual animal behaviour with earthquakes can potentially create false alarms and unnecessary anxiety among people that live in earthquake risk zones. Recently large frog swarms in China and elsewhere have been reported as earthquake precursors in the media. By examining international media reports of frog swarms since 1850 in comparison to earthquake data, it was concluded that frog swarms are naturally occurring dispersal behaviour of juveniles and are not associated with earthquakes. However, the media in seismic risk areas may be more likely to report frog swarms, and more likely to disseminate reports on frog swarms after earthquakes have occurred, leading to an apparent link between frog swarms and earthquakes. Abstract In short-term earthquake risk forecasting, the avoidance of false alarms is of utmost importance to preclude the possibility of unnecessary panic among populations in seismic hazard areas. Unusual animal behaviour prior to earthquakes has been reported for millennia but has rarely been scientifically documented. Recently large migrations or unusual behaviour of amphibians have been linked to large earthquakes, and media reports of large frog and toad migrations in areas of high seismic risk such as Greece and China have led to fears of a subsequent large earthquake. However, at certain times of year large migrations are part of the normal behavioural repertoire of amphibians. News reports of “frog swarms” from 1850 to the present day were examined for evidence that this behaviour is a precursor to large earthquakes. It was found that only two of 28 reported frog swarms preceded large earthquakes (Sichuan province, China in 2008 and 2010). All of the reported mass migrations of amphibians occurred in late spring, summer and autumn and appeared to relate to small juvenile anurans (frogs and toads). It was concluded that most reported “frog swarms” are actually normal behaviour, probably caused by

  13. From integrated observation of pre-earthquake signals towards physical-based forecasting: A prospective test experiment

    NASA Astrophysics Data System (ADS)

    Ouzounov, D.; Pulinets, S. A.; Tramutoli, V.; Lee, L.; Liu, J. G.; Hattori, K.; Kafatos, M.

    2013-12-01

    We are conducting an integrated study involving multi-parameter observations over different seismo- tectonics regions in our investigation of phenomena preceding major earthquakes. Our approach is based on a systematic analysis of several selected parameters namely: gas discharge; thermal infrared radiation; ionospheric electron concentration; and atmospheric temperature and humidity, which we suppose are associated with earthquake preparation phase. We intended to test in prospective mode the set of geophysical measurements for different regions of active earthquakes and volcanoes. In 2012-13 we established a collaborative framework with the leading projects PRE-EARTHQUAKE (EU) and iSTEP3 (Taiwan) for coordinate measurements and prospective validation over seven test regions: Southern California (USA), Eastern Honshu (Japan), Italy, Turkey, Greece, Taiwan (ROC), Kamchatka and Sakhalin (Russia). The current experiment provided a 'stress test' opportunity to validate the physical based approach in teal -time over regions of high seismicity. Our initial results are: (1) Prospective tests have shown the presence in real time of anomalies in the atmosphere before most of the significant (M>5.5) earthquakes in all regions; (2) False positive rate alarm is different for each region and varying between 50% (Italy, Kamchatka and California) to 25% (Taiwan and Japan) with a significant reduction of false positives when at least two parameters are contemporary used; (3) One of most complex problem, which is still open, was the systematic collection and real-time integration of pre-earthquake observations. Our findings suggest that the physical based short-term forecast is feasible and more tests are needed. We discus the physical concept we used, the future integration of data observations and related developments.

  14. Earthquake mechanism and seafloor deformation for tsunami generation

    Geist, Eric L.; Oglesby, David D.; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

    2014-01-01

    Tsunamis are generated in the ocean by rapidly displacing the entire water column over a significant area. The potential energy resulting from this disturbance is balanced with the kinetic energy of the waves during propagation. Only a handful of submarine geologic phenomena can generate tsunamis: large-magnitude earthquakes, large landslides, and volcanic processes. Asteroid and subaerial landslide impacts can generate tsunami waves from above the water. Earthquakes are by far the most common generator of tsunamis. Generally, earthquakes greater than magnitude (M) 6.5–7 can generate tsunamis if they occur beneath an ocean and if they result in predominantly vertical displacement. One of the greatest uncertainties in both deterministic and probabilistic hazard assessments of tsunamis is computing seafloor deformation for earthquakes of a given magnitude.

  15. Significant earthquakes on the Enriquillo fault system, Hispaniola, 1500-2010: Implications for seismic hazard

    Bakun, William H.; Flores, Claudia H.; ten Brink, Uri S.

    2012-01-01

    Historical records indicate frequent seismic activity along the north-east Caribbean plate boundary over the past 500 years, particularly on the island of Hispaniola. We use accounts of historical earthquakes to assign intensities and the intensity assignments for the 2010 Haiti earthquakes to derive an intensity attenuation relation for Hispaniola. The intensity assignments and the attenuation relation are used in a grid search to find source locations and magnitudes that best fit the intensity assignments. Here we describe a sequence of devastating earthquakes on the Enriquillo fault system in the eighteenth century. An intensity magnitude MI 6.6 earthquake in 1701 occurred near the location of the 2010 Haiti earthquake, and the accounts of the shaking in the 1701 earthquake are similar to those of the 2010 earthquake. A series of large earthquakes migrating from east to west started with the 18 October 1751 MI 7.4–7.5 earthquake, probably located near the eastern end of the fault in the Dominican Republic, followed by the 21 November 1751 MI 6.6 earthquake near Port-au-Prince, Haiti, and the 3 June 1770 MI 7.5 earthquake west of the 2010 earthquake rupture. The 2010 Haiti earthquake may mark the beginning of a new cycle of large earthquakes on the Enriquillo fault system after 240 years of seismic quiescence. The entire Enriquillo fault system appears to be seismically active; Haiti and the Dominican Republic should prepare for future devastating earthquakes.

  16. Electromechanical phenomena in semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Lew Yan Voon, L. C.; Willatzen, M.

    2011-02-01

    Electromechanical phenomena in semiconductors are still poorly studied from a fundamental and an applied science perspective, even though significant strides have been made in the last decade or so. Indeed, most current electromechanical devices are based on ferroelectric oxides. Yet, the importance of the effect in certain semiconductors is being increasingly recognized. For instance, the magnitude of the electric field in an AlN/GaN nanostructure can reach 1-10 MV/cm. In fact, the basic functioning of an (0001) AlGaN/GaN high electron mobility transistor is due to the two-dimensional electron gas formed at the material interface by the polarization fields. The goal of this review is to inform the reader of some of the recent developments in the field for nanostructures and to point out still open questions. Examples of recent work that involves the piezoelectric and pyroelectric effects in semiconductors include: the study of the optoelectronic properties of III-nitrides quantum wells and dots, the current controversy regarding the importance of the nonlinear piezoelectric effect, energy harvesting using ZnO nanowires as a piezoelectric nanogenerator, the use of piezoelectric materials in surface acoustic wave devices, and the appropriateness of various models for analyzing electromechanical effects. Piezoelectric materials such as GaN and ZnO are gaining more and more importance for energy-related applications; examples include high-brightness light-emitting diodes for white lighting, high-electron mobility transistors, and nanogenerators. Indeed, it remains to be demonstrated whether these materials could be the ideal multifunctional materials. The solutions to these and other related problems will not only lead to a better understanding of the basic physics of these materials, but will validate new characterization tools, and advance the development of new and better devices. We will restrict ourselves to nanostructures in the current article even though the

  17. ANALYSIS ON THE GROUND DESTROYED FEATURES AND TECTONIC STRESS FIELD OF THE 2008 WENCHUAN EARTHQUAKE AND OUR TREATING TACTICS

    NASA Astrophysics Data System (ADS)

    Guo, Y.; Wang, H.; Deng, Z.; You, H.

    2009-12-01

    To research the ground destroyed features and tectonic stress field of the 2008 Wenchuan Earthquake, we went the earthquake-hazard area, Hongkou Town in Dujiangyan City, Yingxiu Town in Wenchuan County, Bailu Town in Pengzhou City, Yinghua Town in Shifang City, Hanwang Town in Mianzhu City and Beichuan Cit early and late twice in 2008. The geological survey was made. Firstly, the ground destroyed features of the Wenchuan Earthquake around both Yingxiu - Beichuan Fracture and Guanxian - Jiangyou Fracture were analyzed. They mainly display as the ground crack ground, road steep slope, ground deformation, road rise high and deformation, road staggering and rupture, etc. Besides, the Wenchuan Earthquake resulted in the great deal of building collapse and lots of bridges damage even break down; It can be seen that the first floor of the building disappeared or damaged seriously; Some building still stood there although damaged by the earthquake; A few of building was damaged slightly and kept intact structure. Furthermore, the earthquake caused earth slide, mudflow and rolling stone, which lead to the building destroyed seriously, river blocked up, the life line engineering destroyed. Secondly, the phenomena of the ground destroy were analyzed preliminarily. The seismic intensity was determined based on the field investigation. The damaged situation of the construction was concluded. Based on the principle of structure geology and making use of the Stereographic projection, the stress field was analyzed according to the attitude, structural nature and relations among the fracture, fault scratch and joint fissure as well as the characteristics of ground deformation thirdly. The geodynamics of the 2008 Wenchuan Earthquake are probed into preliminarily. The main compressive stress (the maximum main stress) σ1 took Northeast by east direction, and the main tensile stress (the minimum main stress)σ3 took Northwest by north direction. The main fracture shows as the right

  18. POST Earthquake Debris Management — AN Overview

    NASA Astrophysics Data System (ADS)

    Sarkar, Raju

    Every year natural disasters, such as fires, floods, earthquakes, hurricanes, landslides, tsunami, and tornadoes, challenge various communities of the world. Earthquakes strike with varying degrees of severity and pose both short- and long-term challenges to public service providers. Earthquakes generate shock waves and displace the ground along fault lines. These seismic forces can bring down buildings and bridges in a localized area and damage buildings and other structures in a far wider area. Secondary damage from fires, explosions, and localized flooding from broken water pipes can increase the amount of debris. Earthquake debris includes building materials, personal property, and sediment from landslides. The management of this debris, as well as the waste generated during the reconstruction works, can place significant challenges on the national and local capacities. Debris removal is a major component of every post earthquake recovery operation. Much of the debris generated from earthquake is not hazardous. Soil, building material, and green waste, such as trees and shrubs, make up most of the volume of earthquake debris. These wastes not only create significant health problems and a very unpleasant living environment if not disposed of safely and appropriately, but also can subsequently impose economical burdens on the reconstruction phase. In practice, most of the debris may be either disposed of at landfill sites, reused as materials for construction or recycled into useful commodities Therefore, the debris clearance operation should focus on the geotechnical engineering approach as an important post earthquake issue to control the quality of the incoming flow of potential soil materials. In this paper, the importance of an emergency management perspective in this geotechnical approach that takes into account the different criteria related to the operation execution is proposed by highlighting the key issues concerning the handling of the construction

  19. POST Earthquake Debris Management - AN Overview

    NASA Astrophysics Data System (ADS)

    Sarkar, Raju

    Every year natural disasters, such as fires, floods, earthquakes, hurricanes, landslides, tsunami, and tornadoes, challenge various communities of the world. Earthquakes strike with varying degrees of severity and pose both short- and long-term challenges to public service providers. Earthquakes generate shock waves and displace the ground along fault lines. These seismic forces can bring down buildings and bridges in a localized area and damage buildings and other structures in a far wider area. Secondary damage from fires, explosions, and localized flooding from broken water pipes can increase the amount of debris. Earthquake debris includes building materials, personal property, and sediment from landslides. The management of this debris, as well as the waste generated during the reconstruction works, can place significant challenges on the national and local capacities. Debris removal is a major component of every post earthquake recovery operation. Much of the debris generated from earthquake is not hazardous. Soil, building material, and green waste, such as trees and shrubs, make up most of the volume of earthquake debris. These wastes not only create significant health problems and a very unpleasant living environment if not disposed of safely and appropriately, but also can subsequently impose economical burdens on the reconstruction phase. In practice, most of the debris may be either disposed of at landfill sites, reused as materials for construction or recycled into useful commodities Therefore, the debris clearance operation should focus on the geotechnical engineering approach as an important post earthquake issue to control the quality of the incoming flow of potential soil materials. In this paper, the importance of an emergency management perspective in this geotechnical approach that takes into account the different criteria related to the operation execution is proposed by highlighting the key issues concerning the handling of the construction

  20. Automatic Earthquake Detection by Active Learning

    NASA Astrophysics Data System (ADS)

    Bergen, K.; Beroza, G. C.

    2017-12-01

    In recent years, advances in machine learning have transformed fields such as image recognition, natural language processing and recommender systems. Many of these performance gains have relied on the availability of large, labeled data sets to train high-accuracy models; labeled data sets are those for which each sample includes a target class label, such as waveforms tagged as either earthquakes or noise. Earthquake seismologists are increasingly leveraging machine learning and data mining techniques to detect and analyze weak earthquake signals in large seismic data sets. One of the challenges in applying machine learning to seismic data sets is the limited labeled data problem; learning algorithms need to be given examples of earthquake waveforms, but the number of known events, taken from earthquake catalogs, may be insufficient to build an accurate detector. Furthermore, earthquake catalogs are known to be incomplete, resulting in training data that may be biased towards larger events and contain inaccurate labels. This challenge is compounded by the class imbalance problem; the events of interest, earthquakes, are infrequent relative to noise in continuous data sets, and many learning algorithms perform poorly on rare classes. In this work, we investigate the use of active learning for automatic earthquake detection. Active learning is a type of semi-supervised machine learning that uses a human-in-the-loop approach to strategically supplement a small initial training set. The learning algorithm incorporates domain expertise through interaction between a human expert and the algorithm, with the algorithm actively posing queries to the user to improve detection performance. We demonstrate the potential of active machine learning to improve earthquake detection performance with limited available training data.

  1. Earthquake sources near Uturuncu Volcano

    NASA Astrophysics Data System (ADS)

    Keyson, L.; West, M. E.

    2013-12-01

    Uturuncu, located in southern Bolivia near the Chile and Argentina border, is a dacitic volcano that was last active 270 ka. It is a part of the Altiplano-Puna Volcanic Complex, which spans 50,000 km2 and is comprised of a series of ignimbrite flare-ups since ~23 ma. Two sets of evidence suggest that the region is underlain by a significant magma body. First, seismic velocities show a low velocity layer consistent with a magmatic sill below depths of 15-20 km. This inference is corroborated by high electrical conductivity between 10km and 30km. This magma body, the so called Altiplano-Puna Magma Body (APMB) is the likely source of volcanic activity in the region. InSAR studies show that during the 1990s, the volcano experienced an average uplift of about 1 to 2 cm per year. The deformation is consistent with an expanding source at depth. Though the Uturuncu region exhibits high rates of crustal seismicity, any connection between the inflation and the seismicity is unclear. We investigate the root causes of these earthquakes using a temporary network of 33 seismic stations - part of the PLUTONS project. Our primary approach is based on hypocenter locations and magnitudes paired with correlation-based relative relocation techniques. We find a strong tendency toward earthquake swarms that cluster in space and time. These swarms often last a few days and consist of numerous earthquakes with similar source mechanisms. Most seismicity occurs in the top 10 kilometers of the crust and is characterized by well-defined phase arrivals and significant high frequency content. The frequency-magnitude relationship of this seismicity demonstrates b-values consistent with tectonic sources. There is a strong clustering of earthquakes around the Uturuncu edifice. Earthquakes elsewhere in the region align in bands striking northwest-southeast consistent with regional stresses.

  2. Supercritical droplet combustion and related transport phenomena

    NASA Technical Reports Server (NTRS)

    Yang, Vigor; Hsieh, K. C.; Shuen, J. S.

    1993-01-01

    An overview of recent advances in theoretical analyses of supercritical droplet vaporization and combustion is conducted. Both hydrocarbon and cryogenic liquid droplets over a wide range of thermodynamic states are considered. Various important high-pressure effects on droplet behavior, such as thermodynamic non-ideality, transport anomaly, and property variation, are reviewed. Results indicate that the ambient gas pressure exerts significant control of droplet gasification and burning processes through its influence on fluid transport, gas-liquid interfacial thermodynamics, and chemical reactions. The droplet gasification rate increases progressively with pressure. However, the data for the overall burnout time exhibit a considerable change in the combustion mechanism at the criticl pressure, mainly as a result of reduced mass diffusivity and latent heat of vaporization with increased pressure. The influence of droplet size on the burning characteristics is also noted.

  3. Analysis of pre-earthquake ionospheric anomalies before the global M = 7.0+ earthquakes in 2010

    NASA Astrophysics Data System (ADS)

    Yao, Y. B.; Chen, P.; Zhang, S.; Chen, J. J.; Yan, F.; Peng, W. F.

    2012-03-01

    The pre-earthquake ionospheric anomalies that occurred before the global M = 7.0+ earthquakes in 2010 are investigated using the total electron content (TEC) from the global ionosphere map (GIM). We analyze the possible causes of the ionospheric anomalies based on the space environment and magnetic field status. Results show that some anomalies are related to the earthquakes. By analyzing the time of occurrence, duration, and spatial distribution of these ionospheric anomalies, a number of new conclusions are drawn, as follows: earthquake-related ionospheric anomalies are not bound to appear; both positive and negative anomalies are likely to occur; and the earthquake-related ionospheric anomalies discussed in the current study occurred 0-2 days before the associated earthquakes and in the afternoon to sunset (i.e. between 12:00 and 20:00 local time). Pre-earthquake ionospheric anomalies occur mainly in areas near the epicenter. However, the maximum affected area in the ionosphere does not coincide with the vertical projection of the epicenter of the subsequent earthquake. The directions deviating from the epicenters do not follow a fixed rule. The corresponding ionospheric effects can also be observed in the magnetically conjugated region. However, the probability of the anomalies appearance and extent of the anomalies in the magnetically conjugated region are smaller than the anomalies near the epicenter. Deep-focus earthquakes may also exhibit very significant pre-earthquake ionospheric anomalies.

  4. Ionospheric earthquake effects detection based on Total Electron Content (TEC) GPS Correlation

    NASA Astrophysics Data System (ADS)

    Sunardi, Bambang; Muslim, Buldan; Eka Sakya, Andi; Rohadi, Supriyanto; Sulastri; Murjaya, Jaya

    2018-03-01

    Advances in science and technology showed that ground-based GPS receiver was able to detect ionospheric Total Electron Content (TEC) disturbances caused by various natural phenomena such as earthquakes. One study of Tohoku (Japan) earthquake, March 11, 2011, magnitude M 9.0 showed TEC fluctuations observed from GPS observation network spread around the disaster area. This paper discussed the ionospheric earthquake effects detection using TEC GPS data. The case studies taken were Kebumen earthquake, January 25, 2014, magnitude M 6.2, Sumba earthquake, February 12, 2016, M 6.2 and Halmahera earthquake, February 17, 2016, M 6.1. TEC-GIM (Global Ionosphere Map) correlation methods for 31 days were used to monitor TEC anomaly in ionosphere. To ensure the geomagnetic disturbances due to solar activity, we also compare with Dst index in the same time window. The results showed anomalous ratio of correlation coefficient deviation to its standard deviation upon occurrences of Kebumen and Sumba earthquake, but not detected a similar anomaly for the Halmahera earthquake. It was needed a continous monitoring of TEC GPS data to detect the earthquake effects in ionosphere. This study giving hope in strengthening the earthquake effect early warning system using TEC GPS data. The method development of continuous TEC GPS observation derived from GPS observation network that already exists in Indonesia is needed to support earthquake effects early warning systems.

  5. Scale-invariant structure of energy fluctuations in real earthquakes

    NASA Astrophysics Data System (ADS)

    Wang, Ping; Chang, Zhe; Wang, Huanyu; Lu, Hong

    2017-11-01

    Earthquakes are obviously complex phenomena associated with complicated spatiotemporal correlations, and they are generally characterized by two power laws: the Gutenberg-Richter (GR) and the Omori-Utsu laws. However, an important challenge has been to explain two apparently contrasting features: the GR and Omori-Utsu laws are scale-invariant and unaffected by energy or time scales, whereas earthquakes occasionally exhibit a characteristic energy or time scale, such as with asperity events. In this paper, three high-quality datasets on earthquakes were used to calculate the earthquake energy fluctuations at various spatiotemporal scales, and the results reveal the correlations between seismic events regardless of their critical or characteristic features. The probability density functions (PDFs) of the fluctuations exhibit evidence of another scaling that behaves as a q-Gaussian rather than random process. The scaling behaviors are observed for scales spanning three orders of magnitude. Considering the spatial heterogeneities in a real earthquake fault, we propose an inhomogeneous Olami-Feder-Christensen (OFC) model to describe the statistical properties of real earthquakes. The numerical simulations show that the inhomogeneous OFC model shares the same statistical properties with real earthquakes.

  6. Earthquake precursory events around epicenters and local active faults

    NASA Astrophysics Data System (ADS)

    Valizadeh Alvan, H.; Mansor, S. B.; Haydari Azad, F.

    2013-05-01

    The chain of underground events which are triggered by seismic activities and physical/chemical interactions prior to a shake in the earth's crust may produce surface and above surface phenomena. During the past decades many researchers have been carried away to seek the possibility of short term earthquake prediction using remote sensing data. Currently, there are several theories about the preparation stages of earthquakes most of which stress on raises in heat and seismic waves as the main signs of an impending earthquakes. Their differences only lie in the secondary phenomena which are triggered by these events. In any case, with the recent advances in remote sensing sensors and techniques now we are able to provide wider, more accurate monitoring of land, ocean and atmosphere. Among all theoretical factors, changes in Surface Latent Heat Flux (SLHF), Sea & Land Surface Temperature (SST & LST) and surface chlorophyll-a are easier to record from earth observing satellites. SLHF is the amount of energy exchange in the form of water vapor between the earth's surface and atmosphere. Abnormal variations in this factor have been frequently reported as an earthquake precursor during the past years. The accumulated stress in the earth's crust during the preparation phase of earthquakes is said to be the main cause of temperature anomalies weeks to days before the main event and subsequent shakes. Chemical and physical interactions in the presence of underground water lead to higher water evaporation prior to inland earthquakes. In case of oceanic earthquakes, higher temperature at the ocean beds may lead to higher amount of Chl-a on the sea surface. On the other hand, it has been also said that the leak of Radon gas which occurs as rocks break during earthquake preparation causes the formation of airborne ions and higher Air Temperature (AT). We have chosen to perform a statistical, long-term, and short-term approach by considering the reoccurrence intervals of past

  7. Risk in nuclear power plants due to natural hazard phenomena

    SciT

    Lu, S.C.

    1995-12-01

    For the safety of nuclear power plants, it is important to identify potential areas of vulnerabilities to internal as well as external events to which nuclear power plants are exposed. This paper summarizes the risk in nuclear power plants due to natural hazard phenomena such as earthquakes, winds and tornadoes, floods, etc. The reported results are based on a limited number of probabilistic risk assessments (PRAS) performed for a few of the operating nuclear power plants within the United States. The summary includes an importance ranking of various natural hazard phenomena based on their contribution to the plant risk alongmore » with insights observed from the PRA studies.« less

  8. Prediction of earthquake-triggered landslide event sizes

    NASA Astrophysics Data System (ADS)

    Braun, Anika; Havenith, Hans-Balder; Schlögel, Romy

    2016-04-01

    Seismically induced landslides are a major environmental effect of earthquakes, which may significantly contribute to related losses. Moreover, in paleoseismology landslide event sizes are an important proxy for the estimation of the intensity and magnitude of past earthquakes and thus allowing us to improve seismic hazard assessment over longer terms. Not only earthquake intensity, but also factors such as the fault characteristics, topography, climatic conditions and the geological environment have a major impact on the intensity and spatial distribution of earthquake induced landslides. We present here a review of factors contributing to earthquake triggered slope failures based on an "event-by-event" classification approach. The objective of this analysis is to enable the short-term prediction of earthquake triggered landslide event sizes in terms of numbers and size of the affected area right after an earthquake event occurred. Five main factors, 'Intensity', 'Fault', 'Topographic energy', 'Climatic conditions' and 'Surface geology' were used to establish a relationship to the number and spatial extend of landslides triggered by an earthquake. The relative weight of these factors was extracted from published data for numerous past earthquakes; topographic inputs were checked in Google Earth and through geographic information systems. Based on well-documented recent earthquakes (e.g. Haiti 2010, Wenchuan 2008) and on older events for which reliable extensive information was available (e.g. Northridge 1994, Loma Prieta 1989, Guatemala 1976, Peru 1970) the combination and relative weight of the factors was calibrated. The calibrated factor combination was then applied to more than 20 earthquake events for which landslide distribution characteristics could be cross-checked. One of our main findings is that the 'Fault' factor, which is based on characteristics of the fault, the surface rupture and its location with respect to mountain areas, has the most important

  9. Prospective Validation of Pre-earthquake Atmospheric Signals and Their Potential for Short–term Earthquake Forecasting

    NASA Astrophysics Data System (ADS)

    Ouzounov, Dimitar; Pulinets, Sergey; Hattori, Katsumi; Lee, Lou; Liu, Tiger; Kafatos, Menas

    2015-04-01

    We are presenting the latest development in multi-sensors observations of short-term pre-earthquake phenomena preceding major earthquakes. Our challenge question is: "Whether such pre-earthquake atmospheric/ionospheric signals are significant and could be useful for early warning of large earthquakes?" To check the predictive potential of atmospheric pre-earthquake signals we have started to validate anomalous ionospheric / atmospheric signals in retrospective and prospective modes. The integrated satellite and terrestrial framework (ISTF) is our method for validation and is based on a joint analysis of several physical and environmental parameters (Satellite thermal infrared radiation (STIR), electron concentration in the ionosphere (GPS/TEC), radon/ion activities, air temperature and seismicity patterns) that were found to be associated with earthquakes. The science rationale for multidisciplinary analysis is based on concept Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) [Pulinets and Ouzounov, 2011], which explains the synergy of different geospace processes and anomalous variations, usually named short-term pre-earthquake anomalies. Our validation processes consist in two steps: (1) A continuous retrospective analysis preformed over two different regions with high seismicity- Taiwan and Japan for 2003-2009 (2) Prospective testing of STIR anomalies with potential for M5.5+ events. The retrospective tests (100+ major earthquakes, M>5.9, Taiwan and Japan) show STIR anomalous behavior before all of these events with false negatives close to zero. False alarm ratio for false positives is less then 25%. The initial prospective testing for STIR shows systematic appearance of anomalies in advance (1-30 days) to the M5.5+ events for Taiwan, Kamchatka-Sakhalin (Russia) and Japan. Our initial prospective results suggest that our approach show a systematic appearance of atmospheric anomalies, one to several days prior to the largest earthquakes That feature could be

  10. Earthquakes and Schools

    ERIC Educational Resources Information Center

    National Clearinghouse for Educational Facilities, 2008

    2008-01-01

    Earthquakes are low-probability, high-consequence events. Though they may occur only once in the life of a school, they can have devastating, irreversible consequences. Moderate earthquakes can cause serious damage to building contents and non-structural building systems, serious injury to students and staff, and disruption of building operations.…

  11. Coseismic and Afterslip Model Related to 25 April 2015, Mw7.8 Gorkha, Nepal Earthquake and its Potential Future Risk Regions

    NASA Astrophysics Data System (ADS)

    Wang, S.; Xu, C.; Jiang, G.

    2016-12-01

    Evidences from geologic, geophysical and geomorphic prove that 2015 Mw 7.8 Gorkha(Nepal) earthquake happened on the two ramp-flats fault structure of Main Himalayan Thrust(MHT). We approximated this more realistic fault model by a smooth curved fault surface, which was derived by the method of hybrid iterative inversion algorithm(HIIA) with additional constraints from coseismic geodetic data. Then the coseismic slip distribution of 2015 Gorkha earthquake was imaged based on this curved variably triangular sized fault model. The inverted maximum thrust and right-lateral slip components are 6 and 1.5 m, respectively, with the maximum slip magnitude 6.2 m located at a depth of 15 km. The released seismic moment derived from our best slip model is 8.58×1020 Nm, equivalent to a moment magnitude of Mw 7.89. We find two interesting tongue-shape slip areas, the maximum slip is about 1.5 m, along the up-dip of fault plane, which tappers off at the depth of 7 km, the up-dip propagation of ruptures may be impeded by the complicated geometry structures on the MHT interface. Coulomb Failure Stress(CFS), triggered by our optimal slip model, indicating a potential shallower rupture in the future. Considering historical earthquakes distribution and the calculated strain and strain gradient before this earthquake, earthquakes are expected to occur in the northwest areas of the epicenter. The spatio-temporal afterslip model over the first 180 days following the Mw 7.8 main shock was infered from the post-seismic GPS time series. One significant afterslip region can be observed in the downdip of the regions that ruptured by coseismic slip. Another afterslip region arresting our attention, is located around 40 km depth, with about 180 mm slip amplitude, but tappers off at the depth of 50 km. What's more, afterslip mainly occurs within 100 days after the 2015 Gorkha earthquake. Under the assumption of rigidity modulus u = 30 GPa, the released seismic moment by afterslip corresponding

  12. Long-Term RST Analysis of Anomalous TIR Sequences in Relation with Earthquakes Occurred in Greece in the Period 2004-2013

    NASA Astrophysics Data System (ADS)

    Eleftheriou, Alexander; Filizzola, Carolina; Genzano, Nicola; Lacava, Teodosio; Lisi, Mariano; Paciello, Rossana; Pergola, Nicola; Vallianatos, Filippos; Tramutoli, Valerio

    2016-01-01

    Real-time integration of multi-parametric observations is expected to accelerate the process toward improved, and operationally more effective, systems for time-Dependent Assessment of Seismic Hazard (t-DASH) and earthquake short-term (from days to weeks) forecast. However, a very preliminary step in this direction is the identification of those parameters (chemical, physical, biological, etc.) whose anomalous variations can be, to some extent, associated with the complex process of preparation for major earthquakes. In this paper one of these parameters (the Earth's emitted radiation in the Thermal InfraRed spectral region) is considered for its possible correlation with M ≥ 4 earthquakes occurred in Greece in between 2004 and 2013. The Robust Satellite Technique (RST) data analysis approach and Robust Estimator of TIR Anomalies (RETIRA) index were used to preliminarily define, and then to identify, significant sequences of TIR anomalies (SSTAs) in 10 years (2004-2013) of daily TIR images acquired by the Spinning Enhanced Visible and Infrared Imager on board the Meteosat Second Generation satellite. Taking into account the physical models proposed for justifying the existence of a correlation among TIR anomalies and earthquake occurrences, specific validation rules (in line with the ones used by the Collaboratory for the Study of Earthquake Predictability—CSEP—Project) have been defined to drive a retrospective correlation analysis process. The analysis shows that more than 93 % of all identified SSTAs occur in the prefixed space-time window around ( M ≥ 4) earthquake's time and location of occurrence with a false positive rate smaller than 7 %. Molchan error diagram analysis shows that such a correlation is far to be achievable by chance notwithstanding the huge amount of missed events due to frequent space/time data gaps produced by the presence of clouds over the scene. Achieved results, and particularly the very low rate of false positives registered

  13. The Role of Family Phenomena in Posttraumatic Stress in Youth

    PubMed Central

    Deatrick, Janet A.

    2010-01-01

    Topic Youth face trauma that can cause posttraumatic stress (PTS). Purpose 1). To identify the family phenomena used in youth PTS research; and 2). Critically examine the research findings regarding the relationship between family phenomena and youth PTS. Sources Systematic literature review in PsycInfo, PILOTS, CINAHL, and MEDLINE. Twenty-six empirical articles met inclusion criteria. Conclusion Measurement of family phenomena included family functioning, support, environment, expressiveness, relationships, cohesion, communication, satisfaction, life events related to family, parental style of influence, and parental bonding. Few studies gave clear conceptualization of family or family phenomena. Empirical findings from the 26 studies indicate inconsistent empirical relationships between family phenomena and youth PTS, though a majority of the prospective studies support a relationship between family phenomena and youth PTS. Future directions for leadership by psychiatric nurses in this area of research and practice are recommended. PMID:21344778

  14. Demand surge following earthquakes

    Olsen, Anna H.

    2012-01-01

    Demand surge is understood to be a socio-economic phenomenon where repair costs for the same damage are higher after large- versus small-scale natural disasters. It has reportedly increased monetary losses by 20 to 50%. In previous work, a model for the increased costs of reconstruction labor and materials was developed for hurricanes in the Southeast United States. The model showed that labor cost increases, rather than the material component, drove the total repair cost increases, and this finding could be extended to earthquakes. A study of past large-scale disasters suggested that there may be additional explanations for demand surge. Two such explanations specific to earthquakes are the exclusion of insurance coverage for earthquake damage and possible concurrent causation of damage from an earthquake followed by fire or tsunami. Additional research into these aspects might provide a better explanation for increased monetary losses after large- vs. small-scale earthquakes.

  15. Is volcanic phenomena of fractal nature?

    NASA Astrophysics Data System (ADS)

    Quevedo, R.; Lopez, D. A. L.; Alparone, S.; Hernandez Perez, P. A.; Sagiya, T.; Barrancos, J.; Rodriguez-Santana, A. A.; Ramos, A.; Calvari, S.; Perez, N. M.

    2016-12-01

    A particular resonance waveform pattern has been detected beneath different physical volcano manifestations from recent 2011-2012 period of volcanic unrest at El Hierro Island, Canary Islands, and also from other worldwide volcanoes with different volcanic typology. This mentioned pattern appears to be a fractal time dependent waveform repeated in different time scales (periods of time). This time dependent feature suggests this resonance as a new approach to volcano phenomena for predicting such interesting matters as earthquakes, gas emission, deformation etc. as this fractal signal has been discovered hidden in a wide typical volcanic parameters measurements. It is known that the resonance phenomenon occurring in nature usually denote a structure, symmetry or a subjacent law (Fermi et al., 1952; and later -about enhanced cross-sections symmetry in protons collisions), which, in this particular case, may be indicative of some physical interactions showing a sequence not completely chaotic but cyclic provided with symmetries. The resonance and fractal model mentioned allowed the authors to make predictions in cycles from a few weeks to months. In this work an equation for this waveform has been described and also correlations with volcanic parameters and fractal behavior demonstration have been performed, including also some suggestive possible explanations of this signal origin.

  16. Differential energy radiation from two earthquakes in Japan with identical Mw: The Kyushu 1996 and Tottori 2000 earthquakes

    Choy, G.L.; Boatwright, J.

    2009-01-01

    We examine two closely located earthquakes in Japan that had identical moment magnitudes Mw but significantly different energy magnitudes Me. We use teleseismic data from the Global Seismograph Network and strong-motion data from the National Research Institute for Earth Science and Disaster Prevention's K-Net to analyze the 19 October 1996 Kyushu earthquake (Mw 6.7, Me 6.6) and the 6 October 2000 Tottori earthquake (Mw 6.7, Me 7.4). To obtain regional estimates of radiated energy ES we apply a spectral technique to regional (<200 km) waveforms that are dominated by S and Lg waves. For the thrust-fault Kyushu earthquake, we estimate an average regional attenuation Q(f) 230f0:65. For the strike-slip Tottori earthquake, the average regional attenuation is Q(f) 180f0:6. These attenuation functions are similar to those derived from studies of both California and Japan earthquakes. The regional estimate of ES for the Kyushu earthquake, 3:8 ?? 1014 J, is significantly smaller than that for the Tottori earthquake, ES 1:3 ?? 1015 J. These estimates correspond well with the teleseismic estimates of 3:9 ?? 1014 J and 1:8 ?? 1015 J, respectively. The apparent stress (Ta = ??Es/M0 with ?? equal to rigidity) for the Kyushu earthquake is 4 times smaller than the apparent stress for the Tottori earthquake. In terms of the fault maturity model, the significantly greater release of energy by the strike-slip Tottori earthquake can be related to strong deformation in an immature intraplate setting. The relatively lower energy release of the thrust-fault Kyushu earthquake can be related to rupture on mature faults at a subduction environment. The consistence between teleseismic and regional estimates of ES is particularly significant as teleseismic data for computing ES are routinely available for all large earthquakes whereas often there are no near-field data.

  17. Deep crustal earthquakes associated with continental rifts

    NASA Astrophysics Data System (ADS)

    Doser, Diane I.; Yarwood, Dennis R.

    1994-01-01

    Deep (> 20 km) crustal earthquakes have occurred within or along the margins of at least four continental rift zones. The largest of these deep crustal earthquakes ( M ⩾ 5.0) have strike-slip or oblique-slip mechanisms with T-axes oriented similarly to those associated with shallow normal faulting within the rift zones. The majority of deep crustal earthquakes occur along the rift margins in regions that have cooler, thicker crust. Several deep crustal events, however, occur in regions of high heat flow. These regions also appear to be regions of high strain, a factor that could account for the observed depths. We believe the deep crustal earthquakes represent either the relative motion of rift zones with respect to adjacent stable regions or the propagation of rifting into stable regions.

  18. Shallow moonquakes - How they compare with earthquakes

    NASA Technical Reports Server (NTRS)

    Nakamura, Y.

    1980-01-01

    Of three types of moonquakes strong enough to be detectable at large distances - deep moonquakes, meteoroid impacts and shallow moonquakes - only shallow moonquakes are similar in nature to earthquakes. A comparison of various characteristics of moonquakes with those of earthquakes indeed shows a remarkable similarity between shallow moonquakes and intraplate earthquakes: (1) their occurrences are not controlled by tides; (2) they appear to occur in locations where there is evidence of structural weaknesses; (3) the relative abundances of small and large quakes (b-values) are similar, suggesting similar mechanisms; and (4) even the levels of activity may be close. The shallow moonquakes may be quite comparable in nature to intraplate earthquakes, and they may be of similar origin.

  19. The aftershock signature of supershear earthquakes.

    PubMed

    Bouchon, Michel; Karabulut, Hayrullah

    2008-06-06

    Recent studies show that earthquake faults may rupture at speeds exceeding the shear wave velocity of rocks. This supershear rupture produces in the ground a seismic shock wave similar to the sonic boom produced by a supersonic airplane. This shock wave may increase the destruction caused by the earthquake. We report that supershear earthquakes are characterized by a specific pattern of aftershocks: The fault plane itself is remarkably quiet whereas aftershocks cluster off the fault, on secondary structures that are activated by the supershear rupture. The post-earthquake quiescence of the fault shows that friction is relatively uniform over supershear segments, whereas the activation of off-fault structures is explained by the shock wave radiation, which produces high stresses over a wide zone surrounding the fault.

  20. Safety and survival in an earthquake

    ,

    1969-01-01

    Many earth scientists in this country and abroad are focusing their studies on the search for means of predicting impending earthquakes, but, as yet, an accurate prediction of the time and place of such an event cannot be made. From past experience, however, one can assume that earthquakes will continue to harass mankind and that they will occur most frequently in the areas where they have been relatively common in the past. In the United States, earthquakes can be expected to occur most frequently in the western states, particularly in Alaska, California, Washington, Oregon, Nevada, Utah, and Montana. The danger, however, is not confined to any one part of the country; major earthquakes have occurred at widely scattered locations.

  1. Finite element models of earthquake cycles in mature strike-slip fault zones

    NASA Astrophysics Data System (ADS)

    Lynch, John Charles

    The research presented in this dissertation is on the subject of strike-slip earthquakes and the stresses that build and release in the Earth's crust during earthquake cycles. Numerical models of these cycles in a layered elastic/viscoelastic crust are produced using the finite element method. A fault that alternately sticks and slips poses a particularly challenging problem for numerical implementation, and a new contact element dubbed the "Velcro" element was developed to address this problem (Appendix A). Additionally, the finite element code used in this study was bench-marked against analytical solutions for some simplified problems (Chapter 2), and the resolving power was tested for the fault region of the models (Appendix B). With the modeling method thus developed, there are two main questions posed. First, in Chapter 3, the effect of a finite-width shear zone is considered. By defining a viscoelastic shear zone beneath a periodically slipping fault, it is found that shear stress concentrates at the edges of the shear zone and thus causes the stress tensor to rotate into non-Andersonian orientations. Several methods are used to examine the stress patterns, including the plunge angles of the principal stresses and a new method that plots the stress tensor in a manner analogous to seismic focal mechanism diagrams. In Chapter 4, a simple San Andreas-like model is constructed, consisting of two great earthquake producing faults separated by a freely-slipping shorter fault. The model inputs of lower crustal viscosity, fault separation distance, and relative breaking strengths are examined for their effect on fault communication. It is found that with a lower crustal viscosity of 1018 Pa s (in the lower range of estimates for California), the two faults tend to synchronize their