Table 2. One-sided t test for the mean depth of ascending ($\mathbf{\Delta }\overline{\mathit{Z}}\mathit{>}\mathbf{0.5} \text{km}$) and non-ascending ($\mathbf{\Delta }\overline{\mathit{Z}}\mathit{<}\mathbf{0.5} \text{km}$) clusters.

Sample size column indicates N for the two populations considered. ${\overline{Z}}_{\text{remaining}}$ refers to the mean depth of the population consisting of SNB clusters and non-ascending caldera clusters.

Null hypothesis H0	Sample size N	t statistic	P value	Decision
${\overline{Z}}_{\text{Caldera},\text{ascending}}={\overline{Z}}_{\text{Caldera},\text{non}-\text{ascending}}$	18/141	1.43	0.0778	Reject at 10% significance
${\overline{Z}}_{\text{SNB},\text{ascending}}={\overline{Z}}_{\text{SNB},\text{non}-\text{ascending}}$	16/62	0.758	0.226	Accept
${\overline{Z}}_{\text{Caldera},\text{ascending}}={\overline{Z}}_{\text{remaining}}$	18/219	1.75	0.0409	Reject at 10% significance