The effects of small-scale convection in the shallow lithosphere of the North Atlantic

Likerman, Jeremías; Zlotnik, Sergio; Li, Chun‐Feng

doi:10.1093/gji/ggab286

Cited by 3 publications

(1 citation statement)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, the V P anomalies can also be ascribed to SSC at present based on the numerical model of Likerman et al (2021), which suggests that the SSC processes can provide a possible explanation for the Curie-point depth patterns observed in the old (>70-90 Myr old) lithosphere in the North Atlantic. In this case, other processes were required for the origin of the western Pacific seamounts.…”

Section: Small-scale Convection Modelmentioning

confidence: 77%

Seismic Velocity Structure of Upper Mantle Beneath the Oldest Pacific Seafloor: Insights From Finite‐Frequency Tomography

Kang,

Kim,

Hung

et al. 2023

Geochem Geophys Geosyst

View full text Add to dashboard Cite

The oldest oceanic basin (160–180 Ma) in the western Pacific is the birthplace of the Pacific Plate and is thus essential for understanding the formation and evolution of the oceanic plate. However, the upper mantle structure beneath the region has not been thoroughly investigated because of the remoteness and difficulties of long‐term in situ seismic measurements at the ocean bottom. From 2018 to 2019, the Oldest‐1 experiment on the oldest seafloor was conducted as part of the international Pacific Array initiative. We present the first three‐dimensional P‐wave velocity structure down to a depth of 350 km based on the relative travel time residuals of teleseismic earthquakes recorded by 11 broadband ocean‐bottom seismometers operated during the Oldest‐1 experiment. Our result shows a fast P‐wave velocity anomaly (VP perturbation of 2%–4% faster than average) at a depth of 95–185 km beneath the northeast of the study area. This structure is interpreted as evidence of dry, viscous, and rigid materials at depths below the lithosphere. Two slow anomalies (VP perturbation of 2%–4% slower than average) are seen beneath the southwestern and eastern (the oldest seafloor >170 Ma) parts of the array site. The low‐velocity zones are found at depths of 95–305 km. The observed velocity structures can be indicative of plume activities that affected the upper mantle as the Pacific Plate migrated over hotspots from the southeast. Alternatively, the observed velocity features may provide seismic evidence for small‐scale sublithospheric convection.

show abstract

Section: Small-scale Convection Modelmentioning

confidence: 77%

Seismic Velocity Structure of Upper Mantle Beneath the Oldest Pacific Seafloor: Insights From Finite‐Frequency Tomography

Kang,

Kim,

Hung

et al. 2023

Geochem Geophys Geosyst

View full text Add to dashboard Cite

show abstract

Geomechanical modeling of fault-propagation folds: A comparative analysis of finite-element and the trishear kinematic model

Plotek,

Likerman,

Cristallini

2024

Journal of Structural Geology

View full text Add to dashboard Cite

Chemical heterogeneity, convection and asymmetry beneath mid-ocean ridges

Pusok

Katz

May

et al. 2022

Geophysical Journal International

View full text Add to dashboard Cite

Summary Geophysical observations at some mid-ocean ridges document an across-axis asymmetry in indicators of magma production. Other observations are interpreted as showing non-monotonic variations in the depth of the lithosphere–asthenosphere boundary. These patterns are inconsistent with the classical models of mantle corner flow and half-space cooling. To investigate this discrepancy, we use models of coupled magma/mantle dynamics beneath mid-ocean ridges in which phase densities are determined by melt–residue partitioning of iron and magnesium, and bulk density is affected by residual porosity. Our models predict that emergent gradients in density drive ridge-local convection. In particular, we show that convective upwelling is enhanced by porous buoyancy and suppressed by compositional buoyancy. Despite this suppression, models that include both compositional and porous buoyancy are more sensitive to long-wavelength mantle heterogeneity than models with porous buoyancy alone. This sensitivity enables models to readily form across-axis asymmetry of upwelling. In some cases, it leads to lithospheric delamination and time-dependent, small-scale convection. We conclude that melting-induced buoyancy effects may explain the magmatic asymmetry and variations in lithospheric thickness that are inferred from observations.

show abstract

The effects of small-scale convection in the shallow lithosphere of the North Atlantic

Cited by 3 publications

References 53 publications

Seismic Velocity Structure of Upper Mantle Beneath the Oldest Pacific Seafloor: Insights From Finite‐Frequency Tomography

Seismic Velocity Structure of Upper Mantle Beneath the Oldest Pacific Seafloor: Insights From Finite‐Frequency Tomography

Geomechanical modeling of fault-propagation folds: A comparative analysis of finite-element and the trishear kinematic model

Chemical heterogeneity, convection and asymmetry beneath mid-ocean ridges

Contact Info

Product

Resources

About