earthquake detectin using fm radio wave is a topic in whic i have shown methodology about how we can derect earthquake using fm radio waves

1. EARTHQUAKE DETECTION
USING FM RADIO
PRESENTATION BY
SAMRIDHI MANTRI
09EEMEC095

2. CONTENTS
What 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.
Dual frequency method
Classification of Anomalies.
Earthquake Prediction using Khushida’s Methodology.
Conclusion
Reference

3. WHATIS ANEARTHQUAKE?
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 occurrence 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.

5. CAUSES ANDEFFECTSOF AN
EARTHQAUKE
May be natural or man-made.
EFFECTS
Shaking and ground rupture
Landslides and avalanches
Fires
Soil liquefaction
Tsunami
Floods

6. DAMAGESBY EARTHQUAKE

7. FMANDELECTROMAGETICSPECTRUM
Electromagnetic Waves : waves consisting of electric and
magnetic field orthogonal to each other and to the direction of
wave propogation.
FM stands for frequency modulation.
In this signal is modulated according to the frequency of carrier
Usually the bandwidth of FM lies within 88MHz to 108MHz.
VHF (Very High frequency) range is from 30MHz to 300MHz
and FM uses this range.

8. Position of fm in em spectrum

9. PROPAGATION OF VERY HIGHFREQUENCY WAVES
VHF propagation is called Space
wave propagation.
Space wave propagation has two
components-
i) Direct component
ii) 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 geomagnetic field
variation etc.

10. 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.
Ground reflected component: EM wave component that is reflected
from earth surface due to different obstacles include reflection and
diffraction

11. ANOMALIESOBSERVEDINTHERECEPTION
OF FM RADIOWAVE
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

12. EQUIPMENTSUSEDFOR THEDETECTION
OF ANOMALYIN FM

13. Components used in equipment
FM receiver /VHF digital tuning 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 tuning meter-output voltage proportional to
difference between tuned frequency and input frequency.
Chart recorder-records voltage of center tuning meter.
Co-axial cable-For connections.

14. 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.
To detect this we have used dual frequency method

15. DUAL FREQUENCY METHOD
In this method we chose the frequency channels from 76 to 90 MHz
which is used as for FM broadcasting in Japan.
Therefore EM waves is less affected by noise compared with low
frequency band.
In our method, we select two different frequencies (fn and fr) for the
observation channels , which have following characteristics:
a) Fn : this frequency channel is selected from 80.8MHz to
81.2MHz, not assigned for any FM broadcasting use in Japan.
b) Fr : this frequency channel is selected from 76MHz to 90MHz
except from 80.8MHz to 81.2MHz.

16. Then, we can identify whether a received signal is
artificial waves or a broadband EM wave by the dual
frequency method.
At the observatory, four FM antennas are installed on the
roof toward east, west, south and north, respectively.
Each of antenna is connected with two synthesize FM
tuners to measure the EM levels of fn and fr channels
respectively.

17. FM tuner has a receiving bandwidth of 100kHz/3dB and a
noise figure of 2dB. All observation data are stored by the
personal computer.
The observation time is adjusted by the GPS clock every
hours. We are now operating the systems with 120 FM
tuners at 15 observatories in Japan.
The limitation of measuring level is about -120dBm of
FM tuner.

18. Observation
Fig. shows the time variations
of detected EM waves .A sharp
rise is followed by a slower
decline in each direction .
Both of the levels of fn and fr
frequency channels were
similarly fluctuated. The
demodulated signal indicated an
FM noise sound. Therefore, It is
suggested that the detected EM
waves are broadband.
The detected levels slowly
decreased and returned to the
normal level about three hours
later.
The detected peak level was not
observed toward the epicenter
i.e. in west direction.
Detected co-seismic EM waves in
VHF band at Hiroshima City Univ.
on Mar 24,2001 at Geiyo EQ

19. RELATIONBETWEENEARTHQUAKEANDIONOSPHERIC
PLASMADENSITYVARIATION
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.

20. CLASSIFICATIONOF ANOMALIES
CD:-charge-discharge
anomalies
BT:-base-line thickness
anomalies
CDS:-charge-discharge
dominant with superposed BT
BTS:-base line thickness
dominant with superposed CD

21. EARTHQUAKEPREDICTIONUSINGKhUSHIDA’S
METHODOLOGY
Yoshio Khushida and Reiki Khushida
first discovered and implemented VHF
band in EQ detection.
Forecast 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.

22. 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.
Therefore the focus location of
future earthquakes can be
forecasted from the distribution of
CD dominance and BT dominance.

23. CONCLUSION
Thus short term earth-quake prediction can be possible by
studying the anomalies in fm reception
By dual frequency method
A co-seismic EM phenomenon has been detected in VHF
band.
The detected EM waves have broadband spectra.
The VHF emissions have been continued for about three
hours, after the seismic wave.
The detected peak level was not observed toward the
epicenter.

24. REFERENCES
Y.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”
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