MORPHOMETRIC ANALYSIS OF SPATTER LANDFORMS FROM MULTIPLE VOLCANIC FIELDS

Spatter landforms (fissure and point source spatter ramparts) can exhibit a diverse range of morphologies which has not yet been studied with the same rigor as scoria cones. The Small-volume Monogenetic Igneous Landforms and Edifices Statistics (SMILES) catalog contains 178 mafic small-volume volcanic landforms and was created using UAV photogrammetry, open-source LiDAR and DEM repositories. This study examined 31 spatter landforms from the Diamond Craters, Oregon, USA and Askja and Laki of Iceland. Previously collected morphometry from the SMILES database aided in identifying the diversity and unique dimensionless parameters which defines the selected spatter landforms. Parameters include aspect ratio (AR), isoperimetric circularity (IC), crater depth ratio (DR), crater/base area, crater/base perimeter, major chord ratio, and base/height ratio. Selected landforms were limited to a basal width of <2 km and <1 km3. Spatter landforms parameters are AR 0.25 – 0.94, IC 0.43 – 0.98, interior slope angle <63°, and DR 0.04-0.37). Spatter landforms have higher crater/base area ratios and crater/base perimeter ratios than scoria cones. The topographic profile of a spatter landform can range from a bowl shape to saw-toothed. Often spatter landforms craters are comprised of overlapping semi- or half circles inside a more complete circular outline. The SMILES catalog demonstrates the value of evaluating larger populations (N > 20) of similar landforms from multiple volcanic fields using higher-resolution datasets. The technique used in this study can be applied to other volcanic and non-volcanic landforms on Earth, as well as non-terrestrial targets.