Crisis hazard assessment for snow-related lahars from an unforeseen new vent eruption: the 2018 eruption of Kusatsu-Shirane volcano, Japan

Earth, Planets and Space

Table 3 Result of numerical simulations

Scenario	Case name	Bed friction angle (°)	Velocity 1 (m/s)*	Velocity 2 (m/s)*	Travel time (s)**
Scenario	Case name	Bed friction angle (°)	Velocity 1 (m/s)*	Velocity 2 (m/s)*	Highway 292 crossing	Cable car terminal	Yazawa-gawa confluence
A	A-2ph (mod)	25	13.3	3.4	83	137	340
A	A-1ph (max)	5	26.6	14.3	54	84	122
B	B-2ph (mod)	25	23.8	1.3	38	64	270
B	B-1ph (max)	8	28.3	1.6	34	59	186
C	C-2ph (mod)	25	31.6	1.9	36	65	250
C	C-1ph (max)	8	29.7	2.0	37	65	250

*Velocity 1 and Velocity 2 corresponds to upslope segment and downslope one before and after the breakpoint at ca. 2500 m distance
**Travel times show the time when the flow front passes three check points (see the maps of Figs. 11, 12 and 13)