The nature and evolution of mantle upwelling at Ross Island, Antarctica, with implications for the source of HIMU lavas

Phillips, Erin H.; Sims, Kenneth W.W.; Blichert‐Toft, Janne; Aster, R. C.; Gaetani, G. A.; Kyle, Philip R.; Wallace, Paul; Rasmussen, Daniel J.

doi:10.1016/j.epsl.2018.05.049

Cited by 44 publications

(50 citation statements)

References 84 publications

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“…Thus, the slow shear wave speed anomalies beneath Marie Byrd Land are consistent with the presence of a mantle plume, as suggested by some studies (Behrendt, 1999;LeMasurier & Landis, 1996). A comparison of recent global-scale tomographic inversions with deeper resolution than ANT-20 also generally supports slow wave speed structure through and below the transition zone in the Marie Byrd Land region (Phillips et al, 2018).…”

Section: Mantle Velocity Anomalies and The Tectonics Of West Antarcticasupporting

confidence: 75%

“…Finally, along the Transantarctic Mountains, volcanism extends from Mt. Mourning,~100 km south of Ross Island, northward along the length of the mountain range (Kyle, 1990;LeMasurier, 1990;Phillips et al, 2018), except for two outliers in the southern Transantarctic Mountains (Stump et al, 1980). Early Tomographic models (e.g., Danesi & Morelli, 2001;Ritzwoller et al, 2001) lack the resolution necessary to image the upper mantle structures alluded to by geologic and near-surface geophysical studies.…”

Section: West Antarcticamentioning

confidence: 99%

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Seismic Structure of the Antarctic Upper Mantle Imaged with Adjoint Tomography

Lloyd¹,

Wiens²,

Zhu

et al. 2020

JGR Solid Earth

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109

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The upper mantle and transition zone beneath Antarctica and the surrounding oceans are among the poorest‐imaged regions of the Earth's interior. Over the last 15 years, several large broadband regional seismic arrays have been deployed, as have new permanent seismic stations. Using data from 297 Antarctic and 26 additional seismic stations south of ~40°S, we image the seismic structure of the upper mantle and transition zone using adjoint tomography. Over the course of 20 iterations, we utilize phase observations from three‐component seismograms containing P, S, Rayleigh, and Love waves, including reflections and overtones, generated by 270 earthquakes that occurred from 2001–2003 and 2007–2016. The new continental‐scale seismic model (ANT‐20) possesses regional‐scale resolution south of 60°S. In East Antarctica, thinner continental lithosphere is found beneath areas of Dronning Maud Land and Enderby‐Kemp Land. A continuous slow wave speed anomaly extends from the Balleny Islands through the western Ross Embayment and delineates areas of Cenozoic extension and volcanism that span both oceanic and continental regions. Slow wave speed anomalies are also imaged beneath Marie Byrd Land and along the Amundsen Sea Coast, extending to the Antarctic Peninsula. These anomalies are confined to the upper 200–250 km of the mantle, except in the vicinity of Marie Byrd Land where they extend into the transition zone and possibly deeper. Finally, slow wave speeds along the Amundsen Sea Coast link to deeper anomalies offshore, suggesting a possible connection with deeper mantle processes.

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Section: Mantle Velocity Anomalies and The Tectonics Of West Antarcticasupporting

confidence: 75%

Section: West Antarcticamentioning

confidence: 99%

Seismic Structure of the Antarctic Upper Mantle Imaged with Adjoint Tomography

Lloyd¹,

Wiens²,

Zhu

et al. 2020

JGR Solid Earth

Self Cite

109

View full text Add to dashboard Cite

show abstract

“…Below 200 km where the sensitivity of surface wave degrades, it is unclear whether this anomaly continues deeper into the uppermost mantle. Its detailed linkage to midmantle low velocity anomaly, as noted by Phillips et al (2018), is not constrained by this study. Figure 12 presents a set of expanded images of the MBL for the upper mantle.…”

Section: /2017jb015346mentioning

confidence: 65%

The Crust and Upper Mantle Structure of Central and West Antarctica From Bayesian Inversion of Rayleigh Wave and Receiver Functions

Wiens²,

et al. 2018

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We construct a new seismic model for central and West Antarctica by jointly inverting Rayleigh wave phase and group velocities along with P wave receiver functions. Ambient noise tomography exploiting data from more than 200 seismic stations deployed over the past 18 years is used to construct Rayleigh wave phase and group velocity dispersion maps. Comparison between the ambient noise phase velocity maps with those constructed using teleseismic earthquakes confirms the accuracy of both results. These maps, together with P receiver function waveforms, are used to construct a new 3‐D shear velocity (Vs) model for the crust and uppermost mantle using a Bayesian Monte Carlo algorithm. The new 3‐D seismic model shows the dichotomy of the tectonically active West Antarctica (WANT) and the stable and ancient East Antarctica (EANT). In WANT, the model exhibits a slow uppermost mantle along the Transantarctic Mountains (TAMs) front, interpreted as the thermal effect from Cenozoic rifting. Beneath the southern TAMs, the slow uppermost mantle extends horizontally beneath the traditionally recognized EANT, hypothesized to be associated with lithospheric delamination. Thin crust and lithosphere observed along the Amundsen Sea coast and extending into the interior suggest involvement of these areas in Cenozoic rifting. EANT, with its relatively thick and cold crust and lithosphere marked by high Vs, displays a slower Vs anomaly beneath the Gamburtsev Subglacial Mountains in the uppermost mantle, which we hypothesize may be the signature of a compositionally anomalous body, perhaps remnant from a continental collision.

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“…In steady state, lithospheric mantle temperature anomalies of ±100 • C would lead to ∼ ±10 mW/m 2 changes in surface heat flow. While this variability does not account for the large range in point estimates of heat flow across WA (e.g., 69 mW/m 2 , Engelhardt, 2004; 115 mW/m 2 , Morin et al, 2010;and 285 mW/m 2 , Fisher et al, 2015), it is consistent with the variability in regional heat flow (Schroeder et al, 2014;Maule et al, 2005;Pollard et al, 2005), and may be large enough to affect basal ice conditions. With regard to mantle viscosity, O'Donnell et al 2017showed that ±100 • C temperature variations in the upper mantle can result in viscosity changes of ∼2 orders of magnitude, which Barletta et al (2018) argued can have a significant impact on ice sheet stability by influencing glacial isostatic adjustment.…”

Section: Discussionmentioning

confidence: 93%

Heterogeneous upper mantle structure beneath the Ross Sea Embayment and Marie Byrd Land, West Antarctica, revealed by P-wave tomography

White-Gaynor

Nyblade

Aster

et al. 2019

Earth and Planetary Science Letters

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We present an upper mantle P-wave velocity model for the Ross Sea Embayment (RSE) region of West Antarctica, constructed by inverting relative P-wave travel-times from 1881 teleseismic earthquakes recorded by two temporary broadband seismograph deployments on the Ross Ice Shelf, as well as by regional ice-and rock-sited seismic stations surrounding the RSE. Faster upper mantle P-wave velocities (∼ +1%) characterize the eastern part of the RSE, indicating that the lithosphere in this part of the RSE may not have been reheated by mid-to-late Cenozoic rifting that affected other parts of the Late Cretaceous West Antarctic Rift System. Slower upper mantle velocities (∼ −1%) characterize the western part of the RSE over a ∼500 km-wide region, extending from the central RSE to the Transantarctic Mountains (TAM). Within this region, the model shows two areas of even slower velocities (∼ −1.5%) centered beneath Mt. Erebus and Mt. Melbourne along the TAM front. We attribute the broader region of slow velocities mainly to reheating of the lithospheric mantle by Paleogene rifting, while the slower velocities beneath the areas of recent volcanism may reflect a Neogene-present phase of rifting and/or plume activity associated with the formation of the Terror Rift. Beneath the Ford Ranges and King Edward VII Peninsula in western Marie Byrd Land, the P-wave model shows lateral variability in upper mantle velocities of ±0.5% over distances of a few hundred km. The heterogeneity in upper mantle velocities imaged beneath the RSE and western Marie Byrd Land, assuming no significant variation in mantle composition, indicates variations in upper mantle temperatures of at least 100 • C. These temperature variations could lead to differences in surface heat flow of ∼ ±10 mW/m 2 and mantle viscosity of 10 2 Pa s regionally across the study area, possibly influencing the stability of the West Antarctic Ice Sheet by affecting basal ice conditions and glacial isostatic adjustment.

show abstract

The nature and evolution of mantle upwelling at Ross Island, Antarctica, with implications for the source of HIMU lavas

Cited by 44 publications

References 84 publications

Seismic Structure of the Antarctic Upper Mantle Imaged with Adjoint Tomography

Seismic Structure of the Antarctic Upper Mantle Imaged with Adjoint Tomography

The Crust and Upper Mantle Structure of Central and West Antarctica From Bayesian Inversion of Rayleigh Wave and Receiver Functions

Heterogeneous upper mantle structure beneath the Ross Sea Embayment and Marie Byrd Land, West Antarctica, revealed by P-wave tomography

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