Journal of Geophysics
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Detection and mapping of Earth body resonances with continuous GPS
Get PDFI recently reported temporal proof that Mw5.6+ strong earthquakes occur due to (as the lithosphere rides on) vast waves of the tidally driven and gravitationally aided 1–72h long-periodic Earth body resonance (EBR). Here I report a methodologically independent spatial proof of EBR, conclusively showing that tremors are not the only earthquake type caused by mechanical resonance: observations of actual EBR waves in solid matter using continuous Global Positioning System (cGPS) and of their triggering Mw5.6+ earthquakes. Superharmonic resonance periods from the EBR’s 55’–15 days (0.303 mHz–0.7716 μHz) band are thus recoverable in spectra of International Terrestrial Reference Frame (ITRF2014) positional components solved kinematically from 30-s cGPS samplings. The signal is so pure, strong, and stable that even daylong components are constantly periodic at or above 99%-significance, with very high statistical fidelity, ϕ≫12, and ϕ≪12 characterizing overtones or undertones. cGPS stations have diurnal EBR fingerprints: unique sets of ~13–18 EBR frequencies, most clearly formed during ~Mw6+ quiescence, enabling depiction of EBR orientation for real-time EBR mapping. Furthermore, weeklong component time series reveal complete EBR and expected undertones as the signature of EBR’s companion sympathetic resonances, with very high ϕ≫12. Also, I demonstrate EBR mapping using the Mexico City–Los Angeles–San Francisco cGPS profile alongside a tectonic plate boundary, successfully depicting the preparation phase of the 2020 Puerto Rico Mw6.4–Mw6.6 earthquakes sequence. I finish by showing that the EBR triggered the 2019 Ridgecrest Mw6.4–Mw7.1 earthquakes sequence. EBR maps can now be produced for seismic prediction/forecasting and unobscuring (decoupling EBR frequencies) from geophysical observables like stress and strain. EBR engulfs the Earth’s crust, forming the resonance wind whose role and incessantness demote mantle convection from the working hypothesis of geophysics and whose applications include geophysical prospecting and detection at all scales and times. A previously unaccounted-for fundamental force of geophysics, the impulsive EBR spans the vastest energy bands, invalidating any previous claims of seismic detections of gravitational wave signals from deep space, such as by the LIGO experiment.
ARK: https://n2t.net/ark:/88439/x073994
Permalink: https://geophysicsjournal.com/article/313
Earth body resonance. J. Geophys. 63(1):15-29
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Scaling relations for energy magnitudes
Get PDFHomogenizing earthquake catalogs is an effort critical to fundamentally improving seismic studies for next-generation seismology. The preparation of a homogenous earthquake catalog for a seismic region requires scaling relations to convert different magnitude types, like the mb and Ms, to a homogenous magnitude, such as the seismic moment scale, Mwg, and energy magnitude scale, Me. Several recent studies addressed the preparation of homogenized earthquake catalogs, usually involving the estimation of proxies of moment magnitude Mw from local, ML, and teleseismic (Ms and mb) magnitude estimates. Instead of the standard least squares (SLR), most of such studies used the general orthogonal regression (GOR), while some used the Chi-square regression method. Here we critically discuss GOR and Chi-square regression theory and find that both are the same for the linear case — as expected since both stem from the same mathematical concept. Thus to foster an improved understanding of seismicity and seismic hazard, we used GOR methodology and derived global scaling relations individually between body, surface, energy, and seismic moment magnitude scales. For that purpose, we have compiled 13,576 and 13,282 events for Ms from ISC and NEIC, respectively, mb magnitude data for 1,266 events from ISC, 614 events from NEIC, and Mwg magnitude values for 6,690 events from NEIC and GCMT. We have also derived MS,ISC-to-Me and MS,NEIC-to-Me conversion relations in magnitude ranges of 4.7≤MS,ISC≤8.0 and 4.5≤MS,NEIC≤8.0, respectively. Likewise, we obtained mb,ISC-to-Me and mb,NEIC-to-Me conversion relations for ranges of 5.2≤mb,ISC≤6.2 and 5.3≤mb,NEIC≤6.5. Since the number of data points was insufficient to derive the relations, we considered mb,NEIC up to M6.5. Finally, we derived an MWg-to-Me conversion relation for the 5.2≤Mw≤8.2 range of magnitudes with focal depths <70 km. Our scaling relations can be used for homogenizing earthquake catalogs and conducting seismicity and seismic hazard assessment studies with enhanced realism.
ARK: https://n2t.net/ark:/88439/x063005
Permalink: https://geophysicsjournal.com/article/304
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An integrated approach to enhance community resilience in disaster response in Sri Lanka
Get PDFClimate-related extreme geophysical events are among critical global challenges, and Sri Lanka is the second most-affected nation. To minimize disaster impacts and enhance the livability of human settlements, the concept of building community resilience has become crucial in disaster management and preparedness. This paper presents key results and recommendations from an integrated approach to post-disaster recovery interventions and improvements in preparedness activities, to reduce the impact of future disasters and associated risks. We tackled this goal by undertaking a reflective assessment using a case of post-disaster recovery interventions after the floods and landslides of May 2017 in three districts of Sri Lanka. This study emphasizes the need for capitalizing the immediate post-disaster response period to integrate risk reduction and resilience-building activities from the early stages of the recovery timeline. Preparedness and resilience enhancement activities need to align with the Sri Lanka Community Resilience Framework as it can help optimally utilize time and resources to enhance resilience in resources-limited contexts.
ARK: https://n2t.net/ark:/88439/x059916
Permalink: https://geophysicsjournal.com/article/301
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Tomographic imaging of the Andravida blind strike-slip fault (Western Greece)
Get PDFOn 8 June 2008 at 12:25 GMT, a large (Mw6.4) earthquake occurred NE of the town of Andravida in Western Peloponnese, Greece – an area characterized by high seismicity during the last decade. In this study, the local velocity structure of the Andravida Fault Zone (AFZ) is investigated primarily using data recorded during the period 2012-2017 by the Hellenic Unified Seismological Network (HUSN). We selected about 1,500 seismic events recorded by the local HUSN stations as well as the Hellenic Strong-Motion Network (HSMN). By applying tomographic inversion, we produced and interpreted 3D models of VP, VS, and VP/VS ratio in the study area. The spatial distribution of the aftershocks, as well as the 3D model derived by Local Earthquake Tomography (LET), provided evidence for the rupture plane. Surface breaks and minor faults are found to be oblique to the main direction of the AFZ, as a result of a restraining bend in Mtn. Movri and the formation of a positive flower-structure in the shallow layers of the upper crust.
ARK: https://n2t.net/ark:/88439/x014750
Permalink: https://geophysicsjournal.com/article/29
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Earth body resonance
Get PDFThe full range of 72h-forced, 72 superharmonic resonance periods, is detected in time-series of all 866 earthquakes of (robust averages of) Mw5.6+ from USGS, EMSC, and GFZ, 2015-2019 catalogs. The resonance is in the 55’–15 days long-periodic band (0.303 mHz–0.771605 μHz) at 99–67% confidence. Moreover, omitting of the 21 overrepresenting events has improved the result. The signal is clear, strong, and stable – demonstrating beyond doubt that Mw6.2+ seismicity arises due to long-periodic resonance. Remarkably, the natural mode’s cluster was detected too; it averaged 60.1’, while the overall strongest resonance period was also 59.9’, at 2.3 var%, or to within the 1Hz sampling rate – revealing that the 72 h forcer is the modulator of the Earth’s natural period via synchronization. The dominance property of the forcer also follows from detection of its many other fractional multiples: 14/5, 3/2, 5/12, 5/36, etc. After Schumann resonance discovery in the short band (extremely long band of the EM Spectrum), this is the second report ever of a full resonance bundle in any global data, and the first ever in tectonic earthquakes occurrences. The Mw6.2+ seismotectonics arises via resonance-rupture response of tectonic plates and regions to the resonant phase or its fractional multiples. Fundamental questions of geophysics including earthquake prediction can be solved if the Earth is taken to be a multi-oscillator nonlinear system. As an immediate benefit, the find enables a reliable partial seismic anti-forecasting (prediction of seismic quiescence), months ahead globally. This discovery of mechanically induced extreme-band energy on Earth invalidates the main (heat-transfer) geophysical hypothesis and thus should drastically diminish the role of chemistry in geosciences, specifically of geochemistry.
ARK: https://n2t.net/ark:/88439/x020219
Permalink: https://geophysicsjournal.com/article/31
DOI:10.5281/2646487 | online first: 18 Apr 2019 CERN
Moon body resonance, 63(1):30-42
Detection and mapping of Earth body resonances with continuous GPS. J. Geophys. 64(1):12-33
News Feature (2019). The most important scientific discovery of 2019: seismic universe. J. Geophys. 63(1):43-44
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Moon body resonance
Get PDFThe full range of 50 initial, Moon-orbit-forced superharmonic resonance periods is detected in the 1969-1977 time-series of all 12474 consecutive 0.02 Hz moonquakes from the Apollo Program catalog. The resonance is found forcing the strongest-energy (highest-fidelity) part of the 10 hours–100 days (27.78–0.115741 μHz) long-periodic band at 99–67% confidence and below. Resonance signatures of the Moon’s other four long tidal periods – synodic, anomalistic, nodical, and tropical – were also identified but not as separate drivers of body resonance. The spectra were computed using a least-squares spectral analysis method that enabled separation of the signal driver and noise signatures of all lunar tides, as well as extraction of the exact sequence of resonance periods affecting the solid Moon. As the main disruptive phase, the Moon’s orbital period introduces nonlinearity into lunar vibration and thus forces lunar seismotectonics too, giving rise to superharmonic resonance and probably the so-called free librations as well. The spatiotemporally independent computations of Earth and Moon superharmonic resonances from seismicity time-series prove that (the magnification of) macroscopic mechanical resonance is from-quantum-to-macroscopic-scales universal, and therefore as important as gravitation and fundamental forces. I propose then that some of the craters and calderas in our Solar system are petrified evidence of polygonal Faraday latticing. Finally, since only planets with one moon are susceptible to resonance plate tectonics, to prevent Earth energy overload and disintegration, a global geoengineering scheme is proposed to reassign the smaller of Martian moons, Deimos, to Earth so to attenuate Earth plate tectonics while unlocking Mars plate tectonics for natural terraforming.
ARK: https://n2t.net/ark:/88439/x034508
Permalink: https://geophysicsjournal.com/article/73
DOI:10.5281/3376564 | online first: 24 Aug 2019 CERN
Earth body resonance, 63(1):15-29
News Feature (2019). The most important scientific discovery of 2019: seismic universe. J. Geophys. 63(1):43-44
Read the press release for this article
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The most important scientific discovery of 2019: seismic universe
Get PDFStudy of earthquakes and moonquakes finds strong (M6+) quakes and plate tectonics are caused by externally excited resonance instead of mantle convection/inner heat.
ARK: https://n2t.net/ark:/88439/x042047
Permalink: https://geophysicsjournal.com/article/155
Earth body resonance. J. Geophys. 63(1):15-29
Moon body resonance. J. Geophys. 63(1):30-42
Read the press release for this article
 
Statistical investigations on diurnal and annual periodicity and on tidal triggering of local earthquakes in Central Europe
Get PDFTwo regional earthquake catalogues are analysed in order to investigate the existence of diurnal, annual and Earth-tide related periodicities of the occurrence time of seismic events. The first earthquake catalogue covers the total region of the Federal Republic of Germany for the time period 1021-1979 (1530 events) and is investigated with respect to the existence of diurnal and annual periodicities. With the help of the graphical representation for Schuster's test, a midnight and a midday maximum are separated for different intensity classes. A winter maximum present in the data prior to 1930 is absent in the more recent data. It is argued that both diurnal and annual maxima are artifacts due to data sampling problems. The second earthquake catalogue refers to the western part of Germany (Lower Rhine Graben, Rhenish Massif) and the time period 1979-1984 (1012 events of magnitude ML = 0.0–5.1). For the events of this catalogue, a tidal phase is computed according to a model for the triggering of the predominant dip-slip earthquakes. The distribution of phases supports the triggering hypothesis (at the 99% significance level if Schuster's test is applied).
ARK: https://n2t.net/ark:/88439/y094877
Permalink: https://geophysicsjournal.com/article/94
 
A relation between continental heat flow and the seismic reflectivity of the lower crust
Get PDFDeep seismic reflection profiling of the continental crust has found world-wide evidence for prominent reflections from the middle and lower crust. This paper presents evidence for a correlation between the depth to the zone of pronounced reflectivity (the 'reflective lower crust') and the surface heat flow. The highly reflective zone appears to be shallower beneath regions with higher heat flow, suggesting that one condition for the development of the reflective zone is the existence of a sufficiently high temperature in the crust. The data presented in this paper suggest that the highly reflective zone is generally developed only at temperatures higher than 300°-400 °C. This correlation of reflectivity with heat flow implies that crustal reflectivity must be variable on the same time scales on which crustal heat flow is variable. This constraint appears to favour an origin for the lower crustal reflectivity related either to ductile strain banding or to free fluids that may be transient on geologic time scales, rather than to compositional layering or multiple igneous intrusions that are relatively permanent features of the crust.
ARK: https://n2t.net/ark:/88439/y039633
Permalink: https://geophysicsjournal.com/article/6
 
Linearized scattering of surface waves on a spherical Earth
Get PDFRecently, a formalism for three-dimensional surface-wave scattering in a plane geometry was derived. Since teleseismic surface-wave data are generally recorded at epicentral distances large enough to be influenced by the sphericity of the Earth, it is necessary to find the effects of a spherical geometry on surface-wave scattering. The theory of surface-wave scattering relies heavily on a dyadic decomposition of the Green's function, and a new derivation is given for the (dyadic) Green's function of a spherically symmetric Earth. This new derivation employs Poisson's sum formula and is more rigorous than previous derivations. Using the dyadic Green's function, a relation is established with the scattering theory in a flat geometry. This finally leads to a linearized formalism for three-dimensional surface-wave scattering on a sphere. Even for shallow surface waves the effects of sphericity are important and necessitate a modification of the propagator terms in the expression for the scattered surface waves.
ARK: https://n2t.net/ark:/88439/y032183
Permalink: https://geophysicsjournal.com/article/78