An earthquake precursor study has been conducted using normalized polarization ratio analysis based on Fast Fourier Transform (FFT). Three earthquakes in 2020 that have the magnitude (M) ≥ 5 and epicenter distance (R) ≤ 100 km were selected to be analyzed. The night-time geomagnetic signals of X, Y, and Z components from the Sukabumi geomagnetic station (SKB) were extracted at frequencies 0.01 Hz until 0.06 Hz to analyze the SDR value of the SZ/SG component and determine the optimum frequency for detecting earthquake precursors. The results show that frequency 0.06 Hz is optimum to detect a possible earthquake precursor 1 day before the M5 earthquake on March 10, 2020 (EQ1). Meanwhile, the frequencies 0.03 Hz, 0.04 Hz, and 0.06 Hz are optimum to detect the possible precursors for the M5.1 earthquake on July 7, 2020 (EQ2) in a similar period, about 9.5 - 4 weeks before EQ2.

1.
L.
Prawirodirdjo
,
Y.
Bock
,
J. F.
Genrich
,
S. S. O.
Puntodewo
,
J.
Rais
,
C.
Subarya
, and
S.
Sutisna
,
J. of Geophysical Research
105
,
343
363
(
2000
).
2.
A.
Schekotov
,
E.
Fedorov
,
Y.
Hobara
,
M.
Hayakawa
,
J Atmos Elect
33
,
41
51
(
2013
).
3.
F.
Febriani
,
P.
Han
,
C.
Yoshino
,
K.
Hattori
,
B.
Nurdiyanto
,
N.
Effendi
,
I.
Maulana
,
Suhardjono
and
E.
Gaffar
,
Nat. Hazards Earth Syst. Sci.
14
,
789
798
(
2014
).
4.
O.
Chavez
,
R.
Perez-Enriquez
,
J. A.
Cruz-Abeyro
,
J. R.
Millan-Almaraz
,
A.
Kotsarenko
, and
E.
Rojas
,
Nat. Hazards Earth Syst. Sci.
11
,
2021
2027
(
2011
).
5.
G.
Xu
,
p.
Han
,
Q.
Huang
,
K.
Hattori
,
F
Febriani
and
H.
Yamaguchi
,
J Asian Earth Sci
77
,
59
65
(
2013
).
6.
S.
Ahadi
,
N. T.
Puspito
,
G.
Ibrahim
,
S.
Saroso
,
K.
Yumoto
and
M.
Muzli
,
J. Math. Fund. Sci.
47
,
84
103
(
2015
).
7.
p.
Han
,
K.
Hattori
,
Q.
Huang
,
S.
Hirooka
and
C.
Yoshino
,
J Asian Earth Sci
129
,
13
21
(
2016
).
8.
S. K.
Sahoo
,
K. M.
Rao
,
M. S. B. S.
Prasad
,
C. P.
Simha
and
S.
Joshi
,
Arch. Appl. Sci. Res.
8
,
113
117
(
2016
).
9.
K. A.
Yusof
,
N. S. A.
Hamid
,
M.
Abdullah
,
S.
Ahadi
and
A.
Yoshikawa
,
Acta Geophys
67
,
1297
1306
(
2019
).
10.
F.
Febriani
,
T.
Anggono
,
Syuhada
,
A. D.
Prasetio
,
C. N.
Dewi
,
A. S.
Hak
and
S.
Ahadi
, “
Investigation of the ultra low frequency (ULF) geomagnetic anomalies prior to the Lebak, Banten earthquake (M=6.1; January 23, 2018
),” in
The 5th International Symposium on Frontier of Applied Science, AIP Conference Proceedings 2256
, edited by
M.
Shiddiq
et al. (
AIP Publishing, Melville, NY
,
2020
), p.
090002
.
11.
C. N.
Dewi
,
F.
Febriani
,
T.
Anggono
,
B.
Soedjatmiko
,
A. D.
Prasetio
and
S.
Ahadi
, “
The ULF geomagnetic anomalous signal associated with Nias earthquake M5.3 North Sumatra Indonesia on September 6, 2018
,” in
The 4th Padjajaran International Physics Symposium, J. Phys.: Conf. Ser. 1568
, edited by
T.
Saragi
, et al
(
IOP Publishing, Bristol, UK
,
2020
), p.
012027
.
12.
F.
Febriani
,
S.
Ahadi
,
T.
Anggono
,
C. N.
Dewi
and
A. D.
Prasetio
, “
Applying Wavelet Analysis to Asses the Ultra Low Frequency (ULF) Geomagnetic Anomalies prior to M6.1 Banten Earthquake (2018)
,” in
International Conference on the Ocean and Earth Science, IOP Conference Series: Earth and Environmental Science
789
(
1
), edited by Z. Arifin
et
al.
(
IOP Publishing, Bristol, UK
,
2020
), p.
012064
.
13.
D. A.
Stanica
and
D.
Stanica
,
Entropy
23
,
233
(
2021
).
14.
E. M.
Takla
,
K.
Yumoto
,
S.
Okano
,
T.
Uozumi
and
S.
Abe
,
NRIAG Journal of Astronomy and Geophysics
2
,
185
195
(
2013
).
15.
K. A.
Yusof
,
M.
Abdullah
,
N. S. A.
Hamid
and
S.
Ahadi
, " On effective ULF frequency ranges for geomagnetic earthquake precursor,"
in International Conference on Space Weather and Satellite Application (ICeSSAT 2018), J. Phys.: Conf. Ser. 1152
, edited by M. H. Jusoh
et
al.
(
IOP Publishing, Bristol, UK
,
2019
), p.
012033
.
16.
Statistics Indonesia, Gender
(
2021
), available at https://www.bps.go.id/subject/12/kependudukan.html#subjekViewTab3.
17.
A.
Sabtaji
,
Buletin Meteorologi, Klimatologi, dan Geofisika
7
,
31
46
(
2020
).
18.
T.
Saito
,
Space Sci. Rev.
10
,
319
412
(
1969
).
19.
M.
Hayakawa
,
T.
Itoh
,
K.
Hattori
and
K.
Yumoto
,
Geophys. Res. Lett
27
,
1531
1534
(
2000
).
20.
K. A.
Yusof
,
M.
Abdullah
,
N. S. A.
Hamid
,
S.
Ahadi
and
A.
Yoshikawa
,
J. Kejuruteraan
3
,
35
41
(
2020
).
21.
p.
Han
,
K.
Hattori
,
M.
Hirokawa
,
J.
Zhuang
,
C-H.
Chen
,
F.
Febriani
,
H.
Yamaguchi
,
C.
Yoshino
,
J-Y.
Liu
and
S.
Yoshida
,
J Geophys Res Space Phys
119
,
4998
5011
(
2014
).
22.
K.
Hattori
,
I.
Takahashi
,
C.
Yoshino
,
N.
Isezaki
,
H.
Iwasaki
,
M.
Harada
,
K.
Kawabata
,
E.
Kopytenko
,
Y.
Kopytenko
,
p.
Maltsev
,
V.
Korepanov
,
O.
Molchanov
,
M.
Hayakawa
,
Y.
Noda
,
T.
Nagao
and
S.
Uyeda
,
Phys Chem Earth
29
,
481
494
(
2004
).
This content is only available via PDF.
You do not currently have access to this content.