ppt quake

EARTHQUAKE DETECTION USING FM RADIO

PRESENTATION BYSUPARNA.K.S

CONTENTSwhat is an Earthquake?Causes and Effects of an Earthquake.Damages by Earth quake.FM and its position in Electromagnetic Spectrum.Propagation of Very High Frequency Wave.Anomalies Observed in the Reception of FM Radio Waves.Equipments Used For the Detection of Anomaly in FM.Possibility of Earthquake Detection by observing the Anomaly in FM.Relation between Earthquake and Ionospheric Plasma Density Variation.Classification of Anomalies.

Earthquake Prediction using Kushida’s Methodology.

CONCLUSIONREFERENCE

WHAT IS AN EARTHQUAKE ?

An earthquake (also known as a quake, tremor or temblor) is the result of a sudden release of energy in the Earth's crust that creates seismic waves.

These seismic waves travels through earth’s interior.

An earthquake's point of initial rupture is called its focus or hypocenter. The epicenter is the point at ground level directly above the hypocenter.

Absolute magnitude is measured in RICHTER or MOMENT MAGNITUDE SCALE and felt magnitude is measured in MERCALLI INTENSITY SCALE.

CAUSES AND EFFECTS OF AN EARTHQAUKE

May be natural or man-made.

EFFECTSShaking and ground ruptureLandslides and avalanchesFiresSoil liquefactionTsunamiFloods

DAMAGES BY EARTHQUAKE

FM AND ITS POSITION IN ELECTROMAGETIC SPECTRUM

Electromagnetic Waves

FM stands for frequency modulation.

Usually the bandwidth of FM lies within 88MHz -- 108MHz.

VHF (Very High frequency) range is from 30MHz to 300MHz and FM uses this range.

PROPAGATION OF VERY HIGH FREQUENCY WAVES

VHF propagation is called Space wave propagation.

Space wave propagation has two components-(a)Direct component,

(b)Indirect or ground reflected component.

Direct component is propagated by two methods (a)Line of sight propagation:-Limited by Curvature of Earth and Height of transmitting and receiving antennas. (b)Scatter propagation:-occurs in ionospheric E-layer due to blobes of air mass and from the ionized trials of meteors ,geomagnetic field variation etc.

Usually the VHF wave penetrates the ionosphere and are lost , but due to the high concentration, electrons and ions in the E-layer having vibration frequency greater than the frequency of FM waves scattering occurs.

ANOMALIES OBSERVED IN THE RECEPTION OF FM RADIO WAVE

Anomalous or strange unwanted reception of radio waves occur beyond the line of sight receiver set.

Short pulses or echoes(duration 100ms) are observed in radio reception due to entry of meteors into the earth’s atmosphere or passage of aircrafts.

Thunderstorms and other weather activities, Geomagnetic disturbances are also responsible for anomalous reception.

Sporadic E layer causes baseline fluctuation.

Before and after earthquake occurs a huge baseline fluctuation called EQ echo(pulse duration-1 to 2 min) which makes the radio reception difficult.

Base line fluctuation due to sporadic E

EQUIPMENTS USED FOR THE DETECTION OF ANOMALY IN FM

FM receiver /VHF digital tunning receiver tuned slightly offset to the frequency of the fm radio station. Yagi-Uda antenna(5 element)-is directed vertically and normal vector of antenna plane is directed with an offset angle towards a fm station located beyond line of sight.Center tunning meter-output voltage proportional to difference between tuned frequency and input frequencyChart recorder-records voltage of center tuning meterCo-axial cable

POSSIBILITY OF EARTHQUAKE DETECTION BY OBSERVING THE ANOMALY IN FM

Radio echo used to appear one to several times in a day and before two to three weeks of earthquake occurrence. After two to nine days from the last appearance of echo earthquake have occurred.High density plasma in ionosphere E layer over the epicenter before and after earthquake. A co-seismic EM phenomenon has been detected in VHF band. The VHF emissions have been continued for about three hours, after the seismic wave.

The starting times of VHF emissions corresponded to arrival times of seismic P- and S-wave, respectively.

Thus short term earth-quake prediction can be possible by studying the anomalies in fm reception

Detected co-seismic EM waves in VHF band at Hiroshima City Univ. on Mar 24,2001 at Geiyo EQ

RELATION BETWEEN EARTHQUAKE AND IONOSPHERIC PLASMA DENSITY VARIATION

possible mechanism for the generation of electromagnetic waves in the lithosphere is to be identified with the micro-fracturing process of rocks. These micro-fractures, in turn, involve the breaking of a large number of atomic bonds, i.e. the covalent or ionic bonds giving rise to the crystalline structure of the rocks. The formation of unbalanced charge distributions, of opposite sign, on the opposite sides of the micro-fractures is to be expected and, consequently, the onset of strong local electric fields which is explaining geo-electric and geomagnetic fields anomalies as well as development of strong ionospheric perturbations preceding strong earthquakes. Ionospheric perturbations by acoustic gravity waves generated by intensive gas discharges from the crust (mainly CO2 ) before earthquakes.

CLASSIFICATION OF ANOMALIES

CD:-charge-discharge anomaliesBT:-base-line thickness anomaliesCDS:-charge-discharge dominant with superposed BTBTS:-base line thickness dominant with superposed CD

EARTHQUAKE PREDICTION USING KUSHIDA’S METHODOLOGY

Yoshio Kushida and Reiki Kushida first discovered and implemented VHF band in EQ detection.

Forcast of date In most cases the first appearance precedence is in the range of 4-8 days.The maximal anomaly precedence is in the range of 2-3 days and preseismic pause in about 1 day.An early warning can be made after the first appearance of the anomaly.the date of future earthquakes can be forecasted by observing the preseismic maximal of the anomaly strength and it can be refined after observing the preseismic pause.

FORECAST OF FOCUS LOCATION

Each receiver is assumed to have a sensitivity region.Mainly depends on CD component.When CD anomalies or CDS anomalies are observed by receiver, sensitive region contain the foci of future earthquake .BT anomalies are observed if the foci of the future earthquake is out of the sensitive regions.BTS anomalies are observed by vicinal receiver in the case the foci of the future earthquake is located close to the border of the sensitive region.The time constant of CD component is about 5-10 min for underground earthquake. Time constant is about 1-2 min when foci of future earthquake is located closer to the sea-shoreTherefore the focus location of future earthquakes can be forecasted from the distribution of CD dominance and BT dominance.

FORECAST OF MAGNITUDE

Depends on the BT component.Depends on significance of CD anomaly

where v0 is the usual baseline thicknessthe strength of BT and BTS anomaly is measured by

CONCLUSION

92 Kushida predictions mentioning the possibility of M ≥ 5.5 event, whereas there were 49 M ≥ 5.5 earthquakes in the Japanese region.

REFERENCESY.Kushida and R.Kushida,”On the possibility of Earthquake Forecast by Radio observation in the VHF band”T.Yoshida and M.Nishi,”Co-seismic VHF Emission Associated with Earthquakes”Wikipedia Search Engine

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