oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Search Results: 1 - 10 of 315 matches for " Earthquakes "
All listed articles are free for downloading (OA Articles)
Page 1 /315
Display every page Item
Exploring E Turkey: Rainfall Precursor Predicts 100% Earthquake in a Consistent Manner in Just 2 Weeks  [PDF]
Prakash Pillai
International Journal of Geosciences (IJG) , 2013, DOI: 10.4236/ijg.2013.44069
Abstract:

Rainfall event is the very specific, reliable unambiguous precursor for the earthquake event. Over the years scientists have hunted for some signal—a precursory sign, however faint—that would allow forecasters to pin-point exactly where and when the big ones will hit. After decades spent searching in vain, many seismologists now doubt whether such a signal even exists. But in a great surprise to everyone, from an ordinary lay man to eminent scientists, 100% earthquakes occur after rainfalls! Though I have the findings for the entire regions of the world, here E Turkey are the region for submission for the period Jan-November, 2012 to study the strong correlation and show the strong evidence to prove that the 100% earthquakes after rainfall in a consistence manner. Anyone can very easily verify the validity of the findings for any forthcoming earthquakes for any regions of E Turkey in just two weeks of period. Nature does not give two different results for the same phenomena, for two different observers. Though there exists a very strong relation between the rainfalls and the earthquakes, scientists and seismologists have not been able to detect and identify this rainfall precursory signal for hundreds of years that consistently occurs before earthquakes. The methodology of rainfall event before earthquakes, even works consistently for earthquake prediction purpose, especially in any regions of the world. Rainfall type precursor is the best approach to predict specific earthquakes, which provide the potential for estimating the epicenter and magnitude of any moderate to strong earthquakes. Earthquakes are more likely when there is rain than it is not. The magnitudes of a resulting individual earthquake depend on the severity of the weather changes. However, in a very few cases the time scales

Deep and Ultra-Deep Earthquakes Worldwide, Possible Anomalies in South America  [PDF]
M. Hagen, A. Azevedo
Natural Science (NS) , 2018, DOI: 10.4236/ns.2018.106022
Abstract: The aim of this paper is to evaluate the worldwide variation of deep and ultra-deep earthquakes (DQ and UDQ) during the period 1996-2017. This project found only three locations around the globe presenting this kind of seismicity. Although there are other global settings showing deep seismicity, they are not periodical and cannot be considered by a statistical view. The three areas with intense activity for DQ and UDQ events are located mostly in subduction areas. The largest variations of DQ and UDQ border the Pacific Ocean and include the North Pacific, South Pacific, and South America. The major difference in this set is that the first two sites are subduction zones and the South American occurrences happened in the interior of the continent. Another anomaly is an internal layer between 300 - 500 km in South America that shows no tremors in the period studied. However, below 500 km activity reappears, even at extreme depths of up to 650 km. We suggested that the reason for those occurrences would be due to an anomaly in the asthenosphere in this region. This anomaly would probably be presenting a breakable material that was pushed by the Nazca platform against the South America plate. Other depths below 100 km in all the regions are discussed as well. We suggested that the reason for those occurrences was an anomaly created in the asthenosphere as part of the process of the South America collision with the Nazca plate. Part of the Nazca plate has subducted below South America, creating a slab as deep as 500 km. The convergent slab is still moving against South America and sinking due to the gravity and rotation of the Earth. The discrepancies in the occurrences we tracked at different locations indicated that this slab had different thicknesses around South America. We found similar results for Vanuatu and Fiji; in these regions UDQ events occur at the subduction zones under the ocean with depths greater than 700 km. Here, a possible explanation is that part of the lithosphere is subducted at these depths and is causing tremors.
Influences of Solar Cycles on Earthquakes  [PDF]
Marilia Tavares, Anibal Azevedo
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.36060
Abstract: This paper inspects possible influence of solar cycles on earthquakes through of statistical analyses. We also discussed the mechanism that would drive the occurrence of increasing of earthquakes during solar maxima. The study was based on worldwide earthquakes events during approximately four hundred years (1600-2010).The increase of earthquakes events followed the Maxima of Solar cycle, and also depends on the tectonic plate location. From 1600 until 1645 events increased during the Maxima in some of the tectonic plates as Pacific, Arabian and South America. The earthquakes analyzed during two grand solar minima, the Maunder (1645-1720) and the Dalton (1790-1820) showed a decrease in the number of earth-quakes and the solar activity. It was observed during these minima a significant number of events at specific geological features. After the last minima (Dalton) the earthquakes pattern increased with solar maxima. The calculations showed that events increasing during solar maxima most in the Pacific, South America or Arabian until 1900. Since there were few records during these three centuries we needed addi-tional analysis on modern data. We took the last four solar cycles events (1950-2010) and made similar calculations. The results agreed with the former calculations. It might be that the mecha-nism for the Sun-Earth connection relies on the solar wind speed. In both records (1600-1900) and (1950-2010) the results showed a significant increase in earthquakes events in some of the tectonic plates linked to solar maxima. The So-lar wind energy striking the Earth’s magneto-sphere affects the entire environment because the pressure on the region increases and the magnetosphere shrinks sometimes four Earth’s radii. This sudden compression causes earth-quakes in specific plates. During the times of solar minima the pressure from the solar wind on the earth decreases, then the magnetosphere expands and earthquakes happen in a different pattern according to the geological feature on earth’s surface less frequently. Solar driven events include coronal mass ejections (CME) and coronal holes, which are at a maximum during the descending phase of solar activity. The tectonic are important because there is he-terogeneity in the crust and the tectonic stress depends on each region. The geo-effectiveness of solar wind from a coronal hole only depends on the position of the hole relative to the Earth and for the CMEs an additional factor is their velocity. The influence of these solar events could be detected from electromagnetic varia-tions on the ground prior
Tsallis-Based Nonextensive Analysis of the Southern California Seismicity
Luciano Telesca
Entropy , 2011, DOI: 10.3390/e13071267
Abstract: Nonextensive statistics has been becoming a very useful tool to describe the complexity of dynamic systems. Recently, analysis of the magnitude distribution of earthquakes has been increasingly used in the context of nonextensivity. In the present paper, the nonextensive analysis of the southern California earthquake catalog was performed. The results show that the nonextensivity parameter q lies in the same range as obtained for other different seismic areas, thus suggesting a sort of universal character in the nonextensive interpretation of seismicity.
California earthquake history
T. Toppozada,D. Branum
Annals of Geophysics , 2004, DOI: 10.4401/ag-3317
Abstract: This paper presents an overview of the advancement in our knowledge of California's earthquake history since ~ 1800, and especially during the last 30 years. We first review the basic statewide research on earthquake occurrences that was published from 1928 through 2002, to show how the current catalogs and their levels of completeness have evolved with time. Then we review some of the significant new results in specific regions of California, and some of what remains to be done. Since 1850, 167 potentially damaging earthquakes of M ~ 6 or larger have been identified in California and its border regions, indicating an average rate of 1.1 such events per year. Table I lists the earthquakes of M ~ 6 to 6.5 that were also destructive since 1812 in California and its border regions, indicating an average rate of one such event every ~ 5 years. Many of these occurred before 1932 when epicenters and magnitudes started to be determined routinely using seismographs in California. The number of these early earthquakes is probably incomplete in sparsely populated remote parts of California before ~ 1870. For example, 6 of the 7 pre-1873 events in table I are of M = 7, suggesting that other earthquakes of M 6.5 to 6.9 occurred but were not properly identified, or were not destructive. The epicenters and magnitudes (M) of the pre-instrumental earthquakes were determined from isoseismal maps that were based on the Modified Mercalli Intensity of shaking (MMI) at the communities that reported feeling the earthquakes. The epicenters were estimated to be in the regions of most intense shaking, and values of M were estimated from the extent of the areas shaken at various MMI levels. MMI VII or greater shaking is the threshold of damage to weak buildings. Certain areas in the regions of Los Angeles, San Francisco, and Eureka were each shaken repeatedly at MMI VII or greater at least six times since ~ 1812, as depicted by Toppozada and Branum (2002, fig. 19).
State-of-the-art of historical earthquake research in Fennoscandia and the Baltic Republics
P. M?ntyniemi,E. S. Husebye,T. R. M. Kebeasy,A. A. Nikonov
Annals of Geophysics , 2004, DOI: 10.4401/ag-3326
Abstract: We review historical earthquake research in Northern Europe. 'Historical' is defined as being identical with seismic events occurring in the pre-instrumental and early instrumental periods between 1073 and the mid-1960s. The first seismographs in this region were installed in Uppsala, Sweden and Bergen, Norway in 1904-1905, but these mechanical pendulum instruments were broad band and amplification factors were modest at around 500. Until the 1960s few modern short period electromagnetic seismographs were deployed. Scientific earthquake studies in this region began during the first decades of the 1800s, while the systematic use of macroseismic questionnaires commenced at the end of that century. Basic research efforts have vigorously been pursued from the 1970s onwards because of the mandatory seismic risk studies for commissioning nuclear power plants in Sweden, Finland, NW Russia, Kola and installations of huge oil platforms in the North Sea. The most comprehensive earthquake database currently available for Northern Europe is the FENCAT catalogue covering about six centuries and representing the accumulation of work conducted by many scientists during the last 200 years. This catalogue is given in parametric form, while original macroseismic observations and intensity maps for the largest earthquakes can be found in various national publications, often in local languages. No database giving intensity data points exists in computerized form for the region. The FENCAT catalogue still contains some spurious events of various kinds but more serious are some recent claims that some of the presumed largest historical earthquakes have been assigned too large magnitude values, which would have implications for earthquake hazard levels implemented in national building codes. We discuss future cooperative measures such as establishing macroseismic data archives as a means for promoting further research on historical earthquakes in Northern Europe.
Earthquakes in India and the Himalaya: tectonics, geodesy and history
R. Bilham
Annals of Geophysics , 2004, DOI: 10.4401/ag-3338
Abstract: The record of earthquakes in India is patchy prior to 1800 and its improvement is much impeded by its dispersal in a dozen local languages, and several colonial archives. Although geological studies will necessarily complement the historical record, only two earthquakes of the dozens of known historical events have resulted in surface ruptures, and it is likely that geological data in the form of liquefaction features will be needed to extend the historical record beyond the most recent few centuries. Damage from large Himalayan earthquakes recorded in Tibet and in Northern India suggests that earthquakes may attain M = 8.2. Seismic gaps along two-thirds of the Himalaya that have developed in the past five centuries, when combined with geodetic convergence rates of approximately 1.8 m/cy, suggests that one or more M = 8 earthquakes may be overdue. The mechanisms of recent earthquakes in Peninsular India are consistent with stresses induced in the Indian plate flexed by its collision with Tibet. A region of abnormally high seismicity in western India appears to be caused by local convergence across the Rann of Kachchh and possibly other rift zones of India. Since the plate itself deforms little, this deformation may be related to incipient plate fragmentation in Sindh or over a larger region of NW India.
Does the sun trigger earthquakes?  [PDF]
Carlos A. Vargas, Emanuel D. Kastle
Natural Science (NS) , 2012, DOI: 10.4236/ns.2012.428079
Abstract: Tavares and Azevedo [1] showed in their article, that there existed a correlation between the solar cycles and the earthquake activity. In their study they used both ancient records, as well as recent seismicity between 1950 and 2010. According to them, a possible link between solar activity and earthquake occurrence is the magnetic field of the earth, that is being changed in shape corresponding to the solar cycles and thus exerts a pressure on the earth’s crust. This study tries to test their results by means of correlation and cointegration, not only using recent solar and earthquake data, but also taking measurements of the Earth’s magnetic field strength into account. The results presented in this work show no clear connection between the seismicity and the 11-year solar cycles. The data rather indicates an anti-periodicity. It is not excluded, that few strong CME events can influence the triggering of earthquake events, however, this effect is presumably small and plays only a minor roll in the faulting process.
Model of the singular current source—The indicator of geodynamic processes in Japan in 2009-2011  [PDF]
Ludmila F. Moskovskaya
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.58A1005
Abstract:

The calculation method of the location of the singular generalized current source according to synchronous measurements of the magnetic field in the remote points is proposed. It is designed for the continuous monitoring of changes of the degree of electromagnetic heterogeneity of the geophysical environment. Regular fluctuations of the apparent distance to the effective single source were recorded according to the magnetic data of the observatories in Japan 2009-2011. They are connected with the rhythm of the geodynamic processes in the vicinity of the station Kakioka. The most significant decrease in the apparent distance was registered in connection with the seismic activation of the region, including the catastrophic earthquake of March 11, 2011 with a magnitude of M = 9.1. The anomalous behavior of the apparent parameters of the generalized source was displayed not less than two weeks before the earthquake. Characteristic changes of the curves were registered in the period of three months.

Control Parameters of Magnitude—Seismic Moment Correlation for the Crustal Earthquakes  [PDF]
Ernes Mamyrov
Open Journal of Earthquake Research (OJER) , 2013, DOI: 10.4236/ojer.2013.23007
Abstract:

In connection with conversion from energy class KR (KR = log10E R, where ER — seismic energy, J) to the universal magnitude estimation of the Tien Shan crustal earthquakes the development of the self-coordinated correlation of the magnitudes (mb , ML, Ms ) and KR with the seismic moment M0 as the base scale became necessary. To this purpose, the first attempt to develop functional correlations in the magnitude—seismic moment system subject to the previous studies has been done. It is assumed that in the expression M (mb , ML , Ms) = Ki + zi log10M0 , the coefficients ki  and zi  are controlled by the parameters of ratio \"\"(where \"\"; f0 —corner frequency, Brune, 1970, 1971; M0, N×m). According to the new theoretical predictions common functional correlation of the advanced magnitudes Mm (mbm = mb , MLm = ML , MSm = MS ) from log10M0log10tand the elastic properties (Ci) can be presented as \"\", where \"\", and \"\", for the averaged elastic properties of

Page 1 /315
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.