Work

Exploration and monitoring of "fairy circles" associated with natural hydrogen seepages with synthetic aperture radar backscatter analysis and interferometry in the São Francisco basin (Brazil)

Year: 2025

Type: article

Abstract: Circular depressions with distinctive vegetation pattern called “fairy circles” can represent a typical type of hydrogen seeps. Vegetation/soil moisture changes and ground motions are mapped using Synthetic Aperture Radar (SAR) backscatter analysis and interferometry in the São Francisco basin (Brazil) exhibiting numerous fairy circles, including the H 2 -emitting Campinas and Baru structures. Results show that some of the fairy circles are active features in terms of vegetation/soil moisture variations and ground motion on relatively short timescales (<5 years). These changing factors, in general, do not seem to be directly linked to each other, and the underlying processes remain unexplored. While large-scale ground motion anomalies are also detected, the Campinas structure represents the most pronounced subsidence signal with up to 1 cm/year, implying its active formation potentially connected to an underlying H 2 system. SAR-based mapping proved to be successful in monitoring the dynamics of fairy circles, providing constraints towards the understanding of potential H 2 seeps.

Source: International Journal of Hydrogen Energy

DOI: 10.1016/j.ijhydene.2025.152767

Authors: Eszter Békési, Alain Prinzhofer, Kristóf Porkoláb, Gábor Tari, Csilla Szárnya

Institutions: HUN-REN Institute of Earth Physics and Space Science, Eötvös Loránd University

Language: English

Topic: Synthetic Aperture Radar (SAR) Applications and Techniques

Subfield: Aerospace Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,730

Funders: Nemzeti Kutatási és Technológiai Hivatal, Nemzeti Kutatási Fejlesztési és Innovációs Hivatal