Earthquake and hurricane coupling

27 Pages·2014·1.39 MB·English

Nat.HazardsEarthSyst.Sci.Discuss.,2,935–961,2014 Natural Hazards O D
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hurricane coupling
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Earthquake and hurricane coupling is D M.N.Dubrovetal.
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ascertained by ground-based laser s
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interferometer and satellite observing P
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techniques r
Conclusions References
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1 2 1 D Tables Figures
M. N. Dubrov , V. A. Volkov , and S. P. Golovachev is
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1Kotel’nikovInstituteofRadioengineeringandElectronics,RussianAcademyofSciences ss J I
Fryazino,MoscowRegion,Russia io
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2InstituteofPhysicsoftheEarth,RussianAcademyofSciences,Moscow,Russia P J I
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Received:12December2013–Accepted:4January2014–Published:30January2014 er Back Close
Correspondenceto:M.N.Dubrov([email protected]) | FullScreen/Esc
PublishedbyCopernicusPublicationsonbehalfoftheEuropeanGeosciencesUnion. D
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Abstract D
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Themostdestructivedisasterssuchasthestrongestearthquakesandthemostpower- s
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ful tropical cyclones can be treated as tightly coupled geophysical phenomena in their io 2,935–961,2014
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origin. Results of comparison of geophysical field variations and seismic activity of the P
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5 Earth have evidently shown the correlation between lithosphere–atmosphere interac- pe Earthquake and
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tive disturbances, tropical cyclonic activity in the World Ocean, and seismic processes hurricane coupling
in the solid Earth. The ground-based laser interferometer techniques being supple- |
mented by satellite observational systems can be considered as promising methods D M.N.Dubrovetal.
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for common earthquake and hurricane monitoring and prediction. c
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10 1 Introduction P
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Catastrophic earthquakes and powerful tropical cyclones (typhoons, hurricanes) are r
Conclusions References
the strongest natural disasters, which bring the colossal human and environmental |
losses, remain not quite clear geophysical phenomena in their origin up to date. The D Tables Figures
wide spread anomalies in deformations (tilts and strains) of the solid Earth which are is
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15 often preceding to the strongest earthquakes, and which are observed in experiments ss J I
by many authors for a long time (Rikitake, 1976; Mogi, 1985), have a great analogy io
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with barometric forerunners of such extreme atmospheric events as storms, typhoons, P
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hurricanesetc.Thesimilaritywillincreaseconsiderablyifwetakeintoaccountthecon- p
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ventionaldilatancy-diffusionearthquakemodelandthefrequentlydetectedcove-shape r
precursor varieties before the most powerful earthquakes (B. I. Volkov et al., 1999; | FullScreen/Esc
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SobolevandPonomarev,2003).Inparticularthedeformation(tiltandstrain)precursors D
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areoftenaccompaniedbythepeculiartremorprecursors,whichareknownasareduc- c Printer-friendlyVersion
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ingofmicro-seismicandacousticnoisebackgroundbeforeearthquakes–quitesimilar s
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as calm before the storm. It was required a few decades to recognize the assumption ion InteractiveDiscussion
of strain-meter inventor (Benioff et al., 1959) that Earth’s background free oscillations P
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in themHz range are excited continuously even on seismically quiet days, and that e
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suchoscillationscouldbearousedbyatmosphericdisturbances(Nishidaetal.,2000). D
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For example, the fundamental spheroidal modes (2.0–7.5mHz) were observed in the c NHESSD
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Earth’soscillationspectrumeveninperiodsoftheleastseismicactivity(Dolgikhetal., s
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1983; Petrova and Volkov, 1996; Kobayashi et al., 1998). The mode amplitudes are n
5 sufficiently large to be attributed to small background earthquakes. The most powerful Pa
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atmospheric disturbances – tropical cyclones (storms, typhoons, hurricanes) achiev- e Earthquake and
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ing the daily dissipation energy orders of 1018–1019 joules (which are compared to the hurricane coupling
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strongest earthquakes) – run out as the proper candidates for such stimulus of global
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perturbations.FromtheabovepointsofviewtheEarthseismicactivityandtropicalcy-
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10 clogenesis should be the tightly bound geophysical processes. Enouncements for this u
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coupling have been already obtained: the interrelation of typhoons and catastrophic s
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earthquakes was found from satellite images of cloudiness over the north-west part n TitlePage
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of Pacific Ocean (Morozova, 2006); a year seasonal correlation of cyclonic and seis- a
p Abstract Introduction
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mic activity has been also approved basing upon the catalogues data for this region r
(Yaroshevich, 2010). Meanwhile the direct measurements of lithosphere and atmo- Conclusions References
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sphere interactions are possible only by the most accurate ground-based supercon-
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ducting (Kobayashi and Nishida, 1998) and laser instruments (Takemoto et al., 2006). is
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But according to world-wide referred papers these facilities have not been applied for u
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investigation of specific interest outlined. Deformations and stress processes accom- io
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panying the powerful earthquakes and their coupling with tropical cyclones were not J I
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observed and studied in experiments up to now. The first approach towards the solu- p
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tion of this problem by means of precise laser interferometer-strain-meters combined r
with high sensitive pendulum instruments and comprehensive satellite observational | FullScreen/Esc
data are presented in this paper.
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25 2 Earth surface deformations and atmosphere disturbances sio InteractiveDiscussion
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The long-term parallel observations of non-stationary phenomena in upper layers of a
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the Earth’s crust and in an atmosphere, which have been carried out by many au- e
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thors with help of the different geophysical instruments during the diverse years, show D
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theexistenceofthedeterminedconnectionbetweenatmosphericandlithosphericpro- c NHESSD
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cesses in a wide frequency band. One could be referred to investigations of the Earth s
crust strains under affection of atmospheric cyclones which was made decades ago ion 2,935–961,2014
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5 (Trubitsyn et al., 1976), or e.g. to the numerical analysis of lithosphere response to a
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atmosphere pressure variations which was performed by far later (Lyubushin, 1992; e Earthquake and
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Latynina and Vasil’ev, 2001; Klügel and Wziontek, 2009). The model of interaction hurricane coupling
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between the solid Earth’s surface waves and atmospheric sound waves was built by
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Kobayashi et al. (1998) and Nishida et al. (2000), who took into account the convec-
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10 tive motions and the heat transport in the atmosphere. This model could explain the u
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random and stochastic disturbances which are always at any seismic or geodynamic s
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records. But the distinguished features of many anomalous processes in these adja- n TitlePage
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cent and interacting geospheres are the presence of sporadic wave-shape and other a
p Abstract Introduction
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extraordinary appearances which are simultaneously recorded both in the lithosphere r
andintheatmosphereoftheEartheventuallyifsucheverydaymeteorologicalinterfer- Conclusions References
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ences as winds, precipitations, and local thermo–mass-exchanges are not accounted
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(Dubrov et al., 1998). The origins of such kind of sporadic “signals” are not quite clear is
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up to now. u
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Asarule,theseanomalouseventsareattendedbythegainingofseismicactivityand io
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often – by powerful earthquakes. As an example of those lithosphere and atmosphere J I
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excitations, we would present the joint data analysis of the two synchronous oper- p
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ating and spatially distanced at 40 km ground-based instruments: seismo-gravimeter r
and laser strainmeter installed in Moscow region (Volkov et al., 1999a). A few month | FullScreen/Esc
observations in 1998 within ultra long period (3min...6h) band have yielded the one
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strikingappearanceofastrongsynchronousgravityandstrain-baricdisturbancewhich is
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has been followed by the essential growth of earth ground oscillations with 4–5h peri- s
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odstogetherwiththeatmosphericpressuremicro-variationsinthesameperiodrange. io InteractiveDiscussion
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This performance was observed 2–7days before the very strong remote earthquake P
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M =8.1inSouthernHemisphere.Thatwasthefirstourgoodapproachindirectfinding p
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the valuable indications of remote earthquake precursors in lithosphere-atmosphere D
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interaction. But the problem had still remained: how we should explain so far distant c NHESSD
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(∼104km)displayofsuchunusualearthquakeforerunner?Whytheseprecursorswere ss
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not noticed or were too small in recordings yielded from another high sensitive laser n
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5 instruments(Takemotoetal.,2006;AmorusoandCrescentini,2009)installeddeepun- a
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derground. The comprehension has come when the activity of tropical cyclones (hur- e Earthquake and
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ricanes, typhoons) has been taken into consideration. The maxima of their dissipation hurricane coupling
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energy rates of 1018-1019 joules per day for the most powerful hurricane (typhoon) of
the highest Category 5 on the Saffir-Simpson hurricane scale (SSHS) are correspon- D M.N.Dubrovetal.
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10 dent to energy orders of the strongest earthquakes with magnitude M=8–9. These cu
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powerful atmosphere events which are permanently performed in tropical regions of s
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the World Ocean could disturb all the Earth (probably from the inner core up to high n TitlePage
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ionosphere) similar to strong earthquakes exciting tremors of the whole Earth in the a
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mHz range. Just this link was lacking in Kobayashi (1998) and Nishida (2000) models r
for adequate explaining the continuous forcing of background Earth’s free oscillations. Conclusions References
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3 Laser interferometers and graviinertial tools in earthquake monitoring c
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The quantitative correlation analysis of geophysical occurrences in lithosphere and ion
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in adjacent geospheres has become possible after the high precision and low noise P
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superconducting gravimeters and long-path laser interferometers (laser strainmeters) e Back Close
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have been manufactured. These instruments remain the most sensitive and appro-
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priate tools for the wideband observations of the Earth’s surface motions up to now | FullScreen/Esc
(Takemoto et al., 2006; Amoruso and Crescentini, 2009). In distinction from high res- D
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olution gravimeters (and seismo-gravimeters) laser strainmeters are more sensitive to c Printer-friendlyVersion
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shareearthdeformationsandconsequentlytooriginofseismicprocessesaswellasto s
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possible involvement of atmosphere disturbances into co-seismic phenomena. These n
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features are also inherent to precise pendulum tiltmeter instruments which are applied a
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in our observations. During the last decades we have collected and summarized the e
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number of experimental data in laser and pendulum instrument geophysical studies D
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of the anomalous deformations and seismo-acoustic phenomena foregoing to earth- c NHESSD
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quakes since our first tangible results (Dubrov et al., 1992; Petrova and Volkov, 1996). s
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The typical examples of the remote earthquake recordings at the Moscow region n
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5 testing site are shown in Fig. 1. The upper trace (27 September 1974, Hokkaido, a
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M =7.0) was obtained by 100m long equal-arms laser strainmeter (Dubrov and Kar- e Earthquake and
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maleeva, 1976). The middle one (20 March 2008, Southern Xinjiang, M =7.2) has hurricane coupling
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been recorded by 100m wideband unequal-arms laser strainmeter (Dubrov et al.,
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2007). Durations of these two records are about of 1h. The earthquake origins are
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10 pointed by arrows and the shear seismic waves with amplitudes of 0.5–1µm appear u
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on the both records 20–30min later. The equal-arms instrument is sensitive to relative s
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base-length variations dL, while the unequal-arms being air-filled and non-tight inter- n TitlePage
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ferometer records both the relative base-length dL variations and air pressure dP vari- a
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ations simultaneously: strain-baric atmosphere perturbations 10min before the main r
shock could be seen on the middle trace of Fig. 1; its amplitude is less than 0.1 mbar. Conclusions References
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Long-term recordings of co-seismic processes during catastrophic Sumatra M =9.1
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(26 December 2004) earthquake are shown on the lower trace of Fig. 1. Two tilt-baric is
anomalies are clearly seen on the uniform linear 2000 instrument drift of 24 days dura- cu
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tion. They occurred 8 days and 3 days before the main shock (pointed by arrow). io
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In results of our experience we have found that the dynamic disturbances of the J I
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Earth’s surface and perturbations in atmosphere have a nearly wave microstructure p
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and are often accompanied by the ascending of seismic activity. By means of spa- r
tiallydistributedlaserinstrumentswecouldobservethetravelingstrain-baricanomalies | FullScreen/Esc
(wave-shape disturbances of the atmospheric pressure and synchronous earth strain,
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gravityandtiltvariations).Theirspreadingvelocitiesvaryfrom30–60kmh−1 iftheyare is
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recorded deep into the continental zone (V. A. Volkov et al., 1999; Dubrov et al., 2007) s
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and up to 250kmh−1 – nearby the coastal region (Dolgikh et al., 2006). The observed io InteractiveDiscussion
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anomalous lithosphere activity (which the earthquake precursors should be attributed P
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to) looks like as interference of the Earth’s surface with atmosphere, hydrosphere in- p
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cluding an underground water level (Dubrov et al., 2007), and upper geosphere layers D
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(Dubrov and Smirnov, 2013). From this point of view the coupling of lithosphere activ- c NHESSD
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ity and powerful processes in the World Ocean is justified and should be taking into s
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account. n
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Ifwecastaglanceattwowellknownandreferredelsewheremaps:(1)theglobalhur-
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ricanes track records, and (2) the global distribution of earthquake centers, we should is
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see two important things. There are few particular regions in the World Ocean basin s
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which show the spatial correlation between earthquake and hurricane occurrences. io
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Theseregionsare:NorthAtlantics(lowcorrelation),SouthWestPacific(moderatecor- P
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relation), and North West Pacific (high correlation). Meanwhile correlation is not ob- p Abstract Introduction
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served in other specific regions, e.g. in South East Pacific and South Atlantics. A lot
Conclusions References
of ideas would be suggested for explanation of this circumstance. There are many |
publications and studies dedicated to earthquakes and hurricanes interaction. But any D Tables Figures
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15 approachtothisproblemshouldbegroundedonthedetailstudiesincludingtheinstru- cu
mental investigations of conditions and situations concerned with such insufficiently s J I
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explored phenomenon. Our feasible attempts to elucidate this subject using original ion
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experimental data are presented below. P
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The correlation between the seismic activity of the Earth and the tropical cyclogen- e Back Close
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esis in the World Ocean we demonstrate by few examples of parallel recordings ob-
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tainedbylong-pathlaserinterferometers,seismo-gravimeters,andtiltmetersduringthe | FullScreen/Esc
powerful earthquakes in 1998–2004. The comparison with global and regional cyclo- D
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genesis has become possible owing to issuing the Catalog of Tropical Cyclones and c Printer-friendlyVersion
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Tropical Disturbances of the World Ocean for 1983–2005 (Pokrovskaya and Sharkov, s
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2006). The comprehensive data bases are collected at the well-known WEB-portals n
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(http://weather.unisys.com/) (http://en.wikipedia.org/wiki/Portal:Tropical_cyclones) re- a
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cent years. Let us consider the regions of the World Ocean mentioned above each D
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4.1 North Atlantic Ocean io 2,935–961,2014
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This active region of the World Ocean is the nearest basin to the place of our instru- p
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ment installations where the studied phenomena developments are the most legible. r
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Exemplary comparison of recorded strain-baric variations and tropical cyclone activity |
in the North Atlantics are presented on Fig. 2. We have performed the analysis of our D M.N.Dubrovetal.
experimental data obtained by 100m laser interferometer located at the Fryazino un- isc
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dergroundtestingsite(Moscowregion)andtwotropicaldisturbanceswhichhavebeen s
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10 detected in the end of September 2001. The tropical disturbance FELIX ATL 0106 ion TitlePage
(Pokrovskaya et al., 2006, pp. 500–501) mounted the typhoon (hurricane) stage on P
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−1 p Abstract Introduction
13–17 September 2001 with maximum wind velocity of 51ms and dissipated on 23 e
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September2001(23September2001,seeFig.2).Butthisdaytheseconddisturbance Conclusions References
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HUMBERTOATL0108mountedtothetyphoon(hurricane)stage–windvelocitymore
than 33ms−1 (left column of the diagram in Fig. 2) and epicenter drift velocity (mid- D Tables Figures
15 dle column of the diagram) established its minimum value about 10 miles h−1 this day. isc
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During 22–24 September 2001 the laser interferometer recorded anomalous wave- s
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form strain-baric variations which have been rarely observed by this instrument (see 3 n
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traces to the right in Fig. 2). a
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Itisremarkablethatthemostintensivewave-shapestrainandatmospherepressure e Back Close
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variations have been recorded just the day 23 September 2001 and in the time for 2h
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preceding the origin of an earthquake which was the nearest seismic event from the
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siteofourobservationsduringtheconsidered3dayinterval.Thisearthquakeoccurred is
in Greece (37.73◦N, 21.04◦E, magnitude M =4.7), its origin time 21:16 23 Septem- cu Printer-friendlyVersion
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25 ber 2001 has been pointed by arrow on Fig. 2. The others from about three dozen sio InteractiveDiscussion
earthquakes M =4.0–5.8 for this period (Geophysical Survey of Russian Academy of n
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Sciences, 2003) were less intensive (M <4.7) or were happened too far from our test- a
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ing site, e.g. in Colombia M =5.8, Alaska M =5.3, New Zealand M =5.0 etc. er
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The recorded temporal strain-baric variations occupied the period range 5–40min. D
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The spatial scale of the observed phenomenon covered the Anatolian and Balkan c NHESSD
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regions that have been approved by the simultaneously recorded ionosphere distur- ss
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bances that refined from the satellite data processing for this period (Dubrov and n
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4.2 South Pacific and Indian Oceans hurricane coupling
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To illustrate the results of measurements concerning this part of the Southern Hemi- D M.N.Dubrovetal.
sphere let us consider already mentioned above the striking detection of anomalous isc
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lithosphere–atmosphere activity that was observed in Moscow region on March 1998. s
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10 The maximum intensity of those gravity and strain-baric perturbations was recorded ion TitlePage
about50hbeforethestrongestearthquakeattheEarthforthewhole1997–1998sea- P
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sons. Because of very large distance to the earthquake region (∼10 km) the con- e
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nection of recorded data to powerful seismic event M =8.1 (NEIC, 1998) for the first
Conclusions References
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opinion seemed to be hardly probable. But thorough analysis of the presented data
brings the new sense of occurring geophysical phenomena. D Tables Figures
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The results of experimental detection of lithosphere–atmosphere processes from c
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13 March 1998 to 31 March 1998 are shown on the left diagram in Fig. 3. The record- ss J I
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ings of atmosphere pressure variations (dP), gravity (dG), and earth surface strains n
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(dL) are presented here. Measurements have been fulfilled at two sites which were a
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20 spatially distanced at 40km one from another within the bounds of Moscow region. er Back Close
These data have been compared with two rows of the most powerful natural perfor-
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mances at the Earth which were going on March 1998:
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1. Three severe tropical cyclones in SW region of Pacific: 16–27 March 1998, Yaly; c Printer-friendlyVersion
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18–31 March 1998, Nathan; 26 March–06 April 1998 Zuman; and severe storm s
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25 (tropical cyclone) Elsie 8–18 March 1998 in SW Indian Ocean (Pokrovskaya and ion InteractiveDiscussion
Sharkov, 2006); P
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2. Three of the strongest earthquakes on this time interval: 25 March 1998, Bal- D
leny Islands, M =8.1; 29 March 1998, Tonga Islands, M =7.2; and 1 April 1998, isc NHESSD
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Southern Sumatra, M =7.0 (NEIC, 1998). ss
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Allthesepowerfulcyclonic(1)andseismic(2)eventsarepresentedontherightdia- P
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graminFig.3.Theorigintimesofcyclonesandtheirdurationsareshownbyhorizontal p
5 e Earthquake and
lines and the strongest seismic events are depicted by vertical arrows. Severe tropi- r
hurricane coupling
cal storm Elsie in the Indian Ocean has been classified as category 2 tropical cyclone |
(SSHS) with maximum winds of V =90–100milesh−1 (42–47ms−1). Two SW Pacific D M.N.Dubrovetal.
m
cyclones Yaly and Zuman had category 2 and 3 tropical cyclone (SSHS) with wind isc
speeds V in peak intensity above 80milesh−1 (36ms−1) and 90milesh−1 (42ms−1) us
10 m s
respectively. The cyclonic condition was notable less disturbed 16 days before the ion TitlePage
Elsie’s origin: the nearest such or higher power tropical cyclones and storms were P
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observed as early as from January up to the first half of February. The low disturbed e
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condition remained so after Zuman dissipation: tropical cyclones of category 2 SSHS
Conclusions References
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or higher were not observed after 6 April within 1997–98 SW Indian Ocean, Australian
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region, and South Pacific cyclone seasons. The Earth’s seismic condition conforms to D Tables Figures
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thiscourseofevents.ItremainedrelativelyquietonFebruaryandApril1998.Thenear- c
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eststrong(M >7.0)earthquakesoccurredbefore:asearlyasin30January(Northern ss J I
Chile, M =7.1) and after: on 3 May 1998 (Southeast of Taiwan, M =7.5). ion
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20 Let’s consider the results of recordings of atmosphere pressure variations, the a
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Earth’s surface strains, and gravity variations, which are presented on the left diagram e Back Close
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in Fig. 3. The strain (dL) and gravity (dG) data show the contrast cove-shape anomaly
| FullScreen/Esc
on the near uniform drift and tidal signals. This anomaly has duration about 6 days by
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18–23 March and agrees with the significant atmospheric pressure (dP) variations. It is
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25 is important that essential decreasing of atmospheric pressure (up to −30mbar) has u
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been started just after tropical cyclone Elsie dissipation and it is the moment when s
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tropical cyclone Yali is reaching hurricane stage: wind velocity has forced more than n
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33ms−1 (see triangular mark in Fig. 3). a
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