Hotspot swells and the lifespan of volcanic ocean islands

Huppert, Kimberly; Perron, J. Taylor; Royden, L.

doi:10.1126/sciadv.aaw6906

Cited by 30 publications

(25 citation statements)

References 123 publications

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“…Their results suggest that there has been only minor thermal erosion of lithosphere, and that the swell is mainly supported by buoyancy variations within the asthenosphere. These factors are corroborated by analysis of the Hawaiian geoid-to-topography ratio and downstream rates of seamount subsidence (Cadio et al, 2012;Huppert et al, 2020). Updating the model to include effects of partial melting and associated depletion of plume-head material suggests a present-day thermal buoyancy flux of Q B =2.2-3.5 Mg s −1 .…”

Section: Revised Estimates Of Hawaiian Buoyancy Fluxmentioning

confidence: 70%

Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy

Hoggard

Parnell‐Turner

White

2020

Earth and Planetary Science Letters

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Mantle convection is the principal mechanism by which heat is transferred from the deep Earth to the surface. Cold subducting slabs sink into the mantle and steadily warm, whilst upwelling plumes carry heat to the base of lithospheric plates where it can subsequently escape by conduction. Accurate estimation of the total heat carried by these plumes is important for understanding geodynamic processes and Earth's thermal budget. Existing estimates, based upon swell geometries and velocities of overriding plates, yield a global heat flux of ∼ 2 TW and indicate that plumes play only a minor role in heat transfer. Here, we revisit the Icelandic and Hawaiian plumes to show that their individual flux estimates may be incorrect due to the assumption that buoyancy is mainly produced within the lithosphere and therefore translates at plate velocities. We develop an alternative methodology that depends upon swell volume, is independent of plate velocities, and allows both for decay of buoyancy through time and for differential motion between asthenospheric buoyancy and the overlying plate. Reanalysis of the Icelandic and Hawaiian swells yields buoyancy fluxes of 4.0 ± 0.5 Mg s −1 and 2.9 ± 0.6 Mg s −1 , respectively. Both swells are used to calibrate a buoyancy decay timescale of ∼ 45 Myr for the new volumetric approach, which enables buoyancy fluxes to be estimated for a global inventory of 53 swells. Estimates from magmatic hotspots yield a cumulative lower bound on global plume flux of 2 TW, which increases to 6 TW if amagmatic swells are also included and if all buoyancy is assumed to be thermal in origin. Our results suggest that upwelling plumes play a significant role in the transfer of heat into the uppermost mantle.

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Section: Revised Estimates Of Hawaiian Buoyancy Fluxmentioning

confidence: 70%

Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy

Hoggard

Parnell‐Turner

White

2020

Earth and Planetary Science Letters

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“…These were the models which were significant for the widest range Because of the effects of the different age ranges of archipelagos, as well as differences in subsidence rates (Huppert et al, 2020), we only compare relative peak diversity for taxa within the same archipelago. The shift in T peak as the parameter estimates change is illustrated in Figure 1 where an asymmetrical ζ(T) model morphs into a symmetrical TT 2 model.…”

Section: Discussionmentioning

confidence: 99%

“…Hotspot archipelagos vary greatly in their development and physical characteristics, which should impact the S-T relationships (Huppert et al, 2020). Some systems may be younger and predominantly on the ascending side of the TT 2 curve, producing an approximately positive S − T relationship (STR).…”

Section: Semi-log Attmentioning

confidence: 99%

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Towards an extended framework for the general dynamic theory of biogeography

Carey

Boland

Weigelt

et al. 2020

Journal of Biogeography

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Aim The General Dynamic Model of island biogeography (GDM) explains patterns of species richness on volcanic hotspot archipelagos with respect to island age (T) and area (A), most commonly employing what we here call semi‐log ATT2 and LogATT2 models. These can be considered direct extensions of semi‐log and power law species‐area relationships (SARs), with a hump‐shaped function of T modelling drivers of biodiversity over and above area per se. We compare these and related models and investigate their conceptual and mathematical connections. Location The Azores, Galapagos, Hawaii, Marquesas, Society Islands, Cape Verde Islands, Canary Islands and Aeolian archipelagos. Taxa Vascular plants, birds, bryophytes, arthropods and molluscs. Methods We gathered species richness data from databases and published sources, resulting in 34 datasets for various taxa. We used the Akaike information criterion corrected for small sample size (AICc) to compare the relative performance of models. We analysed the data at archipelago level and across archipelagos by using mixed effect models. We also calculated the relative time of expected peak diversity (Tpeak) from parameter estimates. Results In almost three‐fourth of the cases the best model overall was one that contained only A or T rather than both predictors. There was greater variance between taxa than between archipelagos. Better dispersed taxa tended to reach peak diversity earlier. The most generally applicable of the models including T were the LogATT2 and LogTT2 models. These have important, previously unrecognized mathematical properties. Main Conclusions SARs and species–time relationships should always be considered as potentially more parsimonious options. Considering the LogATT2 model as a modification of the power law S = cAz, where a lognormal function in T replaces the constant, c allows the construction of an extended framework for the GDM with incorporation of additional predictors such as measures of environmental heterogeneity and application beyond hotspot archipelagos.

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“…Most large‐scale geophysical studies carried out in the Cape Verde Swell suggest that upwelling within the asthenosphere supports the anomalous topography of the Cape Verde Swell, with minor contributions from local thickened oceanic crust and, perhaps, partial thermal rejuvenation of the lithospheric mantle. If large‐scale swelling (dynamic uplift at the scale of the whole archipelago; e.g., Huppert et al, ) were the mechanism responsible for island uplift, then one would expect to find similar uplift in islands with similar age, which is not the case (e.g., Ramalho, Helffrich, Cosca, et al, , Ramalho, Helffrich, Cosca, et al, , Ramalho, Helffrich, Schmidt, et al, ). Therefore, the solution to explain geological evidence should come from local mechanisms.…”

Section: Discussionmentioning

confidence: 99%

The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde

Marques

Hildenbrand

Zeyen

et al. 2020

Geochem Geophys Geosyst

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Dated paleosea level markers and eustatic sea level changes are necessary but not sufficient information to calculate vertical motion rates on oceanic islands. Therefore, we use a procedure in which we work progressively back in time to incorporate the more recent vertical motion rates implied by the youngest paleoshorelines into the vertical motion history of all older shorelines. Specifically, we calculate the time‐averaged vertical motion rates required to explain the present‐day elevations of the dated sequence of paleoshorelines on Santiago volcanic island (Cape Verde). We thus obtain a vertical motion history consisting of time‐averaged vertical motion rates spanning the five intervening periods between paleoshoreline formation and the present day: (1) 5.06 to 3.29 Ma—seamount growth or island subsidence because all the rocks in this period are submarine; (2) fast uplift (approximately 0.96 mm/a) from 3.29 to 2.87 Ma, mostly responsible for putting submarine lavas currently close to 410 m altitude; (3) relatively fast subsidence (approximately −0.11 mm/a) between 2.87 and 2.18 Ma; (4) stagnation from 2.18 to 0.811 Ma; and (5) relatively fast uplift (approximately 0.14 mm/a) between 0.811 and 0 Ma. We numerically tested top‐down (volcanic loading) and bottom‐up (lithosphere thinning, underplating, and mantle plume) mechanisms to explain the inferred vertical movements, and we conclude that volcanic loading and crustal underplating are capable of producing the observed subsidence and uplift, respectively.

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Hotspot swells and the lifespan of volcanic ocean islands

Abstract: Bathymetry and global records of island drowning show that mantle processes control how long hotspot islands stay above water.

Cited by 30 publications

References 123 publications

Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy

Hotspots and mantle plumes revisited: Towards reconciling the mantle heat transfer discrepancy

Towards an extended framework for the general dynamic theory of biogeography

The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde

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