11-11 Syn-emplacement Evolution of a Lava Flow Fractal Dimension

Session: Using Volcanic Deposits to Help Us Understand Volcanic and Magmatic Processes

Presenting Author:

Authors:

Abstract:

We investigated how the fractal dimension of a lava flow evolves during emplacement using both natural and laboratory data. The primary dataset consists of a 9-minute video of a lava flow from the 2022 Meradalir eruption, alongside a 5.5-minute analog (PEG-600) wax flow. Flow margins were traced in QGIS at regular intervals and analyzed using the box-counting method in MATLAB to calculate fractal dimensions. Further, both flows were segmented into left and right sections; finally, the flow front of the lava flow was also separately analyzed. Across both systems, fractal dimensions remained relatively stable over time, with only minor fluctuations (lava: 1.057–1.091; wax: 1.042–1.079). The left and right sections of the natural lava flow advanced over different substrates - pāhoehoe and slabby-rubbly pāhoehoe - but we found no statistically significant difference in their fractal dimension (p = 0.586). The analog flow displayed a slight left–right asymmetry, yielding a lower but still not statistically significant p-value (p = 0.107). The advancing lava flow front showed slightly lower fractal dimensions than the whole flow, but displayed minimal fluctuation over time. An initial increase in margin fractal dimension during the wax flow suggests time-dependent margin complexity, followed by later-stage minimal variability likely driven by small changes in flow conditions. These findings suggest that natural lava flows develop and retain consistent margin complexity during active emplacement, and that analog wax flows can replicate this behavior under controlled conditions.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-7161

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