Detecting the Lava Flow Deposits From 2018 Anak Krakatau Eruption Using Data Fusion Landsat-8 Optic and Sentinel-1 Sar

Abstract

The increasing volcanic activity of Anak Krakatau volcano has raised concerns about a major disaster in the area around the Sunda Strait. The objective of the research is to fuse Landsat-8 OLI (Operational Land Imager) and Sentinel-1 TOPS (Terrain Observation with Progressive Scans), an integration of SAR and optic remote sensing data, in observing the lava flow deposits resulted from Anak Krakatau eruption during the middle 2018 eruption. RGBI and the Brovey transformation were conducted to merge (fuse) the optical and SAR data. The results showed that optical and SAR data fusion sharpened the appearance of volcano morphology and lava flow deposits. The regions are often constrained by cloud cover and volcanic ash, which occurs at the time of the volcanic eruption. The RGBI-VV and Brovey RGB-VV methods provide better display quality results in revealing the morphology of volcanic cone and lava deposits. The entire slopes of Anak Krakatau Volcano, with a radius of about 1 km from the crater is an area prone to incandescent lava and pyroclastic falls. The direction of the lava flow has the potential to spread in all directions. The fusion method of optical Landsat-8 and Sentinel-1 SAR data can be used continuously in monitoring the activity of Anak Krakatau volcano and other volcanoes in Indonesia both in cloudy and clear weather conditions.

Modelling 2018 Anak Krakatoa Flank Collapse and Tsunami: Effect of Landslide Failure Mechanism and Dynamics on Tsunami Generation

“…The three surrounding islands, together with the submarine caldera, are remnants of the 1883 Krakatoa eruption, which has been studied by several authors (Francis and Self 1983;Camus and Vincent 1983;Decker and Hadikusumo 1961;Sigurdsson et al 1991;Deplus et al 1995;Nomanbhoy and Satake 1995;. Anak Krakatoa has frequently erupted since 1927, with eruptions typically strombolian to vulcanian in style, characterized by small explosive eruptions with columns reaching to 1 km in height, pyroclastic and lava flows (Camus et al 1987;Kimata et al 2012;Suwarsono et al 2019). During these eruptions in the last decades, Anak Krakatoa built up to a height of around 330 m above sea level.…”

Lava flow mapping Karangetang Volcano during 2019 eruption using Sentinel-2 Images and Random Forest model

“…Previously, multispectral remote sensing data has been used using a variety of methodologies, from simple-visual detection [6] to more sophisticated techniques, to trace the material flow promptly after an eruption. Surface reflectance change detection mostly uses infrared and near-infrared bands [7]. The most recent technique for mapping the lava flow on Mount Etna, Italy, combined multispectral satellite imagery with machine learning algorithms [8]; [9].…”

Identification of lava presence on Anak Krakatau volcano using normalized hotspot index before a flank collapse in 2018

“…Remote sensing has ability to monitor phenomenon on the earth surface [9][10] [11], and off course to monitor lava occurances. Several studies have been conducted to monitor the activity of this volcano but few of them discuss the lava flow activity [12]. Moreover, the flank collapse was preceded by the high intensity of the lava release.…”

“…On the other hand, remote sensing data can do continuous monitoring over Anak Krakatau volcano. Remote sensing technology has been widely used in volcano monitoring, such as combining SAR (synthetic aperture radar) and optical remote sensing data [12]. Optical imagery can be applied to monitor volcanic activity, such as thermal anomalies and the temperature of pyroclastic flow [16][17].…”