Influence of successive phases of volcanic construction and erosion on Mayotte Island's hydrogeological functioning as determined from a helicopter-borne resistivity survey correlated with borehole geological and permeability data

Vittecoq, Benoît; Deparis, Jacques; Violette, Sophie; Jaouen, Timothée; Lacquement, Frédéric

doi:10.1016/j.jhydrol.2013.11.062

Cited by 20 publications

(13 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The main drivers controlling volcanic island hydrogeological system are classically lithology, primary permeability and weathering processes. On basaltic or hot spot island a decrease of permeability with geological age is generally observed 55 , 56 , but the recurrence of significant energy earthquakes is rather low in such geological context compared to subduction zones. We demonstrate here that this aging effect is not foremost on volcanic island in subductions zones.…”

Section: Discussionmentioning

confidence: 99%

Earthquakes and extreme rainfall induce long term permeability enhancement of volcanic island hydrogeological systems

Vittecoq

Fortin

Maury

et al. 2020

Sci Rep

Self Cite

View full text Add to dashboard Cite

Earthquakes affect near-surface permeability, however temporal permeability evolution quantification is challenging due to the scarcity of observations data. Using thirteen years of groundwater level observations, we highlight clear permeability variations induced by earthquakes in an aquifer and overlaying aquitard. Dynamic stresses, above a threshold value PGV > 0.5 cm s−1, were mostly responsible for these variations. We develop a new model using earth tides responses of water levels between earthquakes. We demonstrate a clear permeability increase of the hydrogeological system, with the permeability of the aquifer increasing 20-fold and that of the aquitard 300-fold over 12 years, induced by fracture creation or fracture unclogging. In addition, we demonstrate unprecedented observations of increase in permeability due to the effect of extreme tropical deluges of rainfall and hurricanes. The water pressure increase induced by the exceptional rainfall events thus act as piston strokes strong enough to unclog congested fractures by colloids, particles or precipitates. Lastly, an analysis of regional permeabilities also highlights a permeability increase over geological timeframes (× 40 per million years), corroborating the trend observed over the last decade. This demonstrates that permeability of aquifers of andesitic volcanic islands, such as the Lesser Antilles, significantly evolve with time due to seismic activity and extreme rainfall.

show abstract

Section: Discussionmentioning

confidence: 99%

Earthquakes and extreme rainfall induce long term permeability enhancement of volcanic island hydrogeological systems

Vittecoq

Fortin

Maury

et al. 2020

Sci Rep

Self Cite

View full text Add to dashboard Cite

show abstract

“…Mapping the 3D limits of each aquifer and defining these boundaries (recharge, prescribed head, no‐flow) will require detailed investigations, which will undoubtedly result in the identification of hundreds of small (at most a few 0.1 km 2 ) aquifers. The high‐resolution helicopter‐borne resistivity survey recently carried out on Mayotte (see the paper by Vittecoq et al ., submitted contemporaneously with this article and only available during the final revision of this article) may lead to an identification if these data are carefully calibrated with field or borehole data; these authors have also shown that the electrical resistivity ranges that they obtained for aquifers and aquicludes may be ambiguous. Vittecoq et al .…”

Section: Hydrogeological Structure and Functioning Of Mayottementioning

confidence: 99%

High‐resolution conceptual hydrogeological model of complex basaltic volcanic islands: a Mayotte, Comoros, case study

et al. 2014

View full text Add to dashboard Cite

International audienceWe present a high-resolution conceptual hydrogeological model for complex basaltic volcanic islands based on Mayotte Island in the Comoros. Its geological structure and hydrogeological functioning are deduced from a large dataset: geological mapping, geophysics, some forty new boreholes, piezometric data, hydraulic conductivity, hydrochemical data, etc. We describe previously unknown deep cut-and-fill palaeovalleys. The resulting conceptual geological and hydrogeological model of the island is very different from the Hawaiian model, in that it lacks a low-elevation basal aquifer and dyke-impounded high-level aquifers. It is closer to the Canary Islands model, which has, however, not yet been described at a high-resolution scale. It does not have a continuous aquifer, but rather a discontinuous succession of perched aquifers separated by aquicludes and aquitards. This results more from the complex geological structure of the island, which has experienced several phases of volcanism, erosion and weathering, than from its age, but is also a result of the high-resolution scale of the model. High-resolution conceptual modelling is now necessary to solve problems of applied geology and hydrogeology

show abstract

“…While groundwater aquifers are clearly identified and reachable in coastal areas (Gingerich & Voss, 2005;Herrera & Custodio, 2014), the thickness of lava flows' unsaturated pile can reach up to thousands of meters in volcanos' central parts. This results in a thick vadose zone where groundwater flows follow complex geological structures due to a polygenetic volcanic activity (Izquierdo, 2014;Vittecoq et al, 2014), and because of the evolution of hydrodynamic properties of volcanic rocks due to weathering and alteration processes (Custodio, 2004;Join et al, 2005;Lachassagne et al, 2014). The groundwater is thus classified in three different aquifer categories based on the above-mentioned geological parameters: shallow aquifers, perched aquifers and basal aquifers (Join et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Hydrogeophysical characterization in a volcanic context from local to regional scales combining airborne electromagnetism and magnetism

Dumont¹,

Reninger²,

Aunay³

et al. 2020

Preprint

View full text Add to dashboard Cite

show abstract

Influence of successive phases of volcanic construction and erosion on Mayotte Island's hydrogeological functioning as determined from a helicopter-borne resistivity survey correlated with borehole geological and permeability data

Cited by 20 publications

References 40 publications

Earthquakes and extreme rainfall induce long term permeability enhancement of volcanic island hydrogeological systems

Earthquakes and extreme rainfall induce long term permeability enhancement of volcanic island hydrogeological systems

High‐resolution conceptual hydrogeological model of complex basaltic volcanic islands: a Mayotte, Comoros, case study

Hydrogeophysical characterization in a volcanic context from local to regional scales combining airborne electromagnetism and magnetism

Contact Info

Product

Resources

About