Fig. 2
From: Physical characteristics of scoriae and ash from 2014–2015 eruption of Aso Volcano, Japan
Photographs of scoriae and their magnified views. a A high-porosity scoria found at the 3rd crater (Fig. 1c). The red curve outlines the scoria. b Magnified view of the high-porosity scoria. Red circles indicate the typical vesicle sizes. c–e A flattened scoria found at the western rim of the 1st crater observed from the top (c) and side (d), and the e broken-out section denoted by the red rectangle in (d). The aspect ratio (thickness/width) of this flattened scoria is 1/3