Fig. 5: Magnitude clustering in laboratory earthquakes.
From: Seismic magnitude clustering is prevalent in field and laboratory catalogs
A Normalized magnitude clustering phenomena for various types of rock fractures on different rock types. Absolute M0 spans of the curves are varied as tests are conducted on different rock types with different data acquisition systems. B The non-clustering observations on the whole catalogs of the rock fractures under dominatingly tensile stress. Catalogs are on tests conducted at University of Minnesota (left), and Halliburton (right), respectively. C–E The induced rock fractures under extending and shear stress35 conditions (left of C), confined and shear stress39 conditions (right of C), tensile stress42,43 conditions (D), and hydraulic fracturing (E)40,41.
