1972 earthquake

• Need to have a map showing the 1951 earthquake sequences and the 1972 earthquake sequences, and the potential location of the 1972 surface rupture

Macroseismic map of this earthquake clearly shows the rupture fault was propagating northward, with unilateral rupture. This is coincide to the aftershock distribution from previous studies. No surface rupture can be found in the field, based on the interview results and the aerial photo investigation

Mainshock magnitude

• It is important to find out what is the magnitude of the mainshock. The magnitude from global catalog is listed below

Source	緯度(N)	經度(E)	深度(km)	規模	Type
NEIC	23.6	121.60	33	7.2	Ms
ISCGEM	23.564	121.539	22.2	7.0	Mw

Aftershocks

Relocated mainshock and aftershocks From 蔣(1984)

地震編號	緯度(N)	經度(E)	深度(km)	規模(mb)	年	月	日	時	分	秒
A	23.59	121.54	29.3	6.1	72	4	24	17	57	22.06
B	23.48	121.39	39.7	5.2	72	4	24	19	32	12.65
C	23.52	121.4	52.5	5.1	72	4	24	20	0	34.81
D	23.62	121.49	32.7	4.8	72	4	24	20	22	43.58
E	23.57	121.41	8.6		72	4	24	20	45	41.19
F	23.71	121.66	42.8		72	4	25	1	30	35.69
G	23.78	121.58	26	5.4	72	4	25	1	58	31.91
H	23.88	121.5	42.7	4.7	72	4	25	3	30	29.68
I	23.92	121.36	11.6		72	4	25	3	44	5.12
J	23.94	121.34	16.2	4.3	72	4	25	3	59	49.68
K	23.75	121.74	16.4		72	4	25	4	34	18.8
L	23.58	121.61	48.4	4.7	72	4	25	7	27	57.24
M	23.85	121.31	28.5	4.6	72	4	27	7	48	28.18
N	23.8	121.56	27.1		72	4	27	22	26	28.38
O	23.9	121.55	33.7	4.8	72	5	2	4	1	21.3
P	23.68	121.08	16.4		72	5	6	16	59	21.34
Q	23.86	121.26	26.1		72	5	25	2	38	48.12
R	23.61	121.7	3	4.5	72	8	1	1	4	44
S	23.9	121.6	36	5.5	72	11	8	22	25	46.5
T	23.95	121.28	22	5.9	72	11	10	2	41	14.5
U	23.87	121.66	27	5.5	72	11	21	10	47	16.4

From 詹(1985)

地震編號	緯度(N)	經度(E)	深度(km)	規模(Mcw)	年	月	日	時	分	秒
A	23.51	121.53	15.42	6.38	72	4	24	17	57	22.01
B	23.52	121.31	1.82	5.51	72	4	24	19	32	11.37
C	23.49	121.25	5.83	4.92	72	4	24	20	0	32.77
D	23.6	121.57	22.05	4.68	72	4	24	20	22	42.35
E	23.62	121.34	3.12	4.24	72	4	24	20	45	42.56
F	23.71	121.55	23.94	4.47	72	4	25	1	30	34.48
G	23.69	121.62	26.12	5.47	72	4	25	1	58	31.55
H	23.65	121.62	25.69	4.4	72	4	25	3	30	24.59
I	23.65	121.58	0.51	4.01	72	4	25	3	44	2.81
J	23.75	121.5	22	4.29	72	4	25	3	59	48.78
K	23.74	121.46	17.26	4.26	72	4	25	4	34	19.88
L	23.58	121.5	21.97	4.37	72	4	25	7	27	55.94
M	23.76	121.29	0.85	4.84	72	4	27	7	48	25.57
N	23.78	121.56	0.98	4.26	72	4	27	22	26	26.51
O	23.78	121.57	0.69	5.16	72	5	2	4	1	18.32
P	23.62	121.32	8.37	4.24	72	5	6	16	59	16.93
Q	23.76	121.37	9.96	4.25	72	5	25	2	38	46.12

from 中央氣象局 民國六十一年台灣地區的地震活動和蘇俄科學家預測發生大海嘯的可能性

地震編號	緯度(N)	經度(E)	深度(km)	規模(M)	年	月	日	時	分
1	22.5	122.3	55	6.7	1972	1	4	11	17
2	22.4	122.2	40	5.1	1972	1	4	20	15
3	20.9	120.2	90	6.5	1972	1	8	13	28
4	24.1	122	40	5	1972	1	14	21	34
5	22.5	122.3	70	7.3	1972	1	25	10	6
6	23	122.3	40	7.1	1972	1	25	11	41
7	24.4	120.3	15	5.3	1972	2	12	9	7
8	24.5	121.9	50	5.4	1972	2	21	17	42
9	22.4	122.1	35	5.6	1972	3	7	14	20
10	24.1	122.5	40	4.8	1972	3	19	21	33
11	23.9	121.9	50	6.3	1972	4	17	18	49
12	24.4	122.5	30	5.2	1972	4	17	19	2
13	23.8	122.4	25	5.6	1972	4	21	21	21
14	23.5	121.5	3	7	1972	4	24	17	57
15	23.5	121.3	5	5.1	1972	4	24	18	15
16	23.6	121.3	5	4.7	1972	4	24	19	19
17	23.6	121.4	5	5.6	1972	4	24	19	32
18	23.6	121.6	20	5.5	1972	4	24	20	0
19	23.6	121.9	10	5	1972	4	24	20	22
20	23.5	121.4	10	5	1972	4	25	1	30
21	23.8	121.6	7.5	5.7	1972	4	25	1	58
22	23.6	121.4	5	4.8	1972	4	25	3	59
23	23.8	121.3	5	5.1	1972	4	25	7	28
24	23.6	121.4	10	5.1	1972	4	27	7	48
25	23.9	122.2	30	5.2	1972	4	28	3	21
26	23.7	121.8	30	5.4	1972	5	2	4	1
27	23.1	121.2	10	5.5	1972	5	5	18	16
28	24.2	121.7	15	6	1972	5	12	9	21
29	23.7	121.5	30	5.2	1972	5	22	20	32
30	24.2	121.5	10	5.3	1972	7	1	2	57
31	23.6	121.3	15	4.8	1972	7	13	21	11
32	23.7	121.1	5	5.1	1972	7	16	21	48
33	23.5	121.9	25	5.2	1972	8	1	1	4
34	23.5	121.8	15	4.9	1972	8	31	9	13
35	24.6	122.7	40	5.3	1972	9	2	10	8
36	22.5	120.9	15	6.5	1972	9	23	3	57
37	22	121.4	45	6.6	1972	9	23	10	14
38	22.7	121.4	30	5.3	1972	9	24	14	44
39	22.6	121.3	20	5.2	1972	9	24	21	9
40	22.2	121.2	30	5.9	1972	9	28	1	54
41	24.3	121.8	20	5	1972	9	29	12	28
42	22.3	121.4	25	5.3	1972	10	6	23	52
43	22.3	121.1	20	5.4	1972	10	21	12	16
44	22.8	120.8	20	5.3	1972	11	7	14	40
45	23.9	121.5	2	5.7	1972	11	8	22	25
46	23.9	121.3	10	6.5	1972	11	10	2	41
47	23.9	121.8	20	6	1972	11	21	10	47
48	23.9	121.4	5	5.5	1972	11	21	10	51
49	23.2	120.4	10	5.4	1972	12	22	9	35
50	23.4	121.6	35	4.8	1972	12	30	5	3

Ground deformations

• Mostly associated to the landslides and the slope failures.
• A more-than-2-km-long fissure is interesting.
• No clear evidence of surface rupture at the base of the coastal range.