-Means Cluster for Seismicity Partitioning and Geological Structure Interpretation, with Application to the Yongshaba Mine (China)

Table 1

Summary of typical seismicity partitioning methods.

No.	Cluster method	Study area	Index for possible optimum cluster number selection	Optimum cluster number	Reference
1	K-Means cluster	Aegean region	Krzanowski–Lai index	20~30	[6]
2	K-Means cluster	Pakistan	Krzanowski–Lai index	19	[7]
3	K-Means cluster	Croatia and Iberian Peninsula	Simplified Silhouette Width Criterion, Davies–Bouldin index, Calinski–Harabasz index and Area index	7 and 16, respectively	[8]
4	K-Means cluster	Gibraltar Arc and Andean regions	Silhouette index	3~4	[9]
5	K-Means cluster	Iran	Silhouette index	6	[10]
6	Hierarchical cluster	Global dataset	Cutoff link length	—	[11–13]
7	Hierarchical cluster	A Canadian mine	Cutoff link length	10	[14, 15]
8	Hierarchical cluster	Zagros region (Iran)	Cutoff link length	5	[16]
9	Hierarchical cluster	United States	Cutoff link length	10	[17]
10	SOM cluster	Iran	Cutoff similarity level	2, 3, 4, 6 and 22	[5]
11	SOM cluster	Iran	Wilk's Lambda and its discrepancy	11	[18]
12	SOM cluster	Iran	Dunn, Davies-Bouldin, Silhouette, C, Calinski–Harabasz, Hartigan and Krzanowski–Lai indexes	9~13	[19]
13	Fuzzy cluster	Iran	Partition density index	16	[4]
14	Fuzzy cluster	Ghazvin canal	Separation index, Xie-Beni index and partition index	12	[20]
15	Fuzzy cluster	South West Colombia	Fuzzy hyper volume and partition density	12	[21]
16	DBSCAN cluster	Japan	Correlation Ecorr and minimum number of objects in a cluster	10	[22]
17	Seismic mass DBSCAN cluster	Hellenic Arc	Correlation Ecorr and minimum number of objects in a cluster	35~40	[23]
18	Point density based cluster	Burmese–Andaman and West Sunda Arc	Cutoff link length	13	[24]
19	TriGen based cluster	Iberian Peninsula	Fitness function	34	[25]
20	MMD, Hierarchical and K-means clusters	Zabrze-Bielszowice coal mine (Poland)	Minimum number of events	6	[26]
21	FCM, DBSCAN, QC and dynamic spatial cluster	Hellenic Arc	—	19	[27]