Paleolatitude of the Hawaiian Hot Spot Since 48 Ma: Evidence for a Mid‐Cenozoic True Polar Stillstand Followed by Late Cenozoic True Polar Wander Coincident With Northern Hemisphere Glaciation

Abstract

Paleospin axis locations since 48 Ma inferred from the distribution of equatorial sediment accumulation rates on the Pacific plate, together with paleomagnetic poles from magnetic anomaly skewness, indicate that the Hawaiian hot spot was nearly fixed in latitude from 48 to 12 Ma, but ≈3° north of its current latitude. From 48 to 12 Ma in the Pacific hot spot reference frame, which we take to be equivalent to the global hot spot reference frame, the spin axis was located near 87°N, 164°E, recording a stillstand in true polar wander. Global hot spots shifted coherently relative to the spin axis since ≈12 Ma, consistent with an episode of true polar wander, which may continue today. The motion of the spin axis away from the Hawaiian hot spot and toward Greenland since ≈12 Ma coincided with, and may have contributed to, the onset of northern hemisphere glaciation.

Hotspot motion caused the Hawaiian-Emperor Bend and LLSVPs are not fixed

“…8). Thus, we conclude that the apparent latitudinal discrepancy from the skewness models is inconsequential, and the related TPW rotation 14,37 unnecessary (see True polar wander based on marine magnetic anomaly skewness, in Methods).…”

“…7). However, these skewness models have also been used to call for a much younger TPW event (after 11 Ma) that would be responsible for North Hemisphere glaciation 37 . The new data from Midway also afford the opportunity to examine this hypothesized rotation.…”

The Case for a Long-Lived and Robust Yellowstone Hotspot

“…20 Ma as it rose obliquely against the base of shallowing lithosphere, ponding beneath thinner lithosphere west of the cratonic boundary. Finally, the uncertainties in the plate models and the possibility of Cenozoic true polar wander (Woodworth and Gordon, 2018) may be significant at this scale. Although formal uncertainties are not typically provided, the differences in the 40± Ma position of the Yellowstone hotspot may give some idea of the variability in models.…”

Uncertainties in Trends of Young Hot Spot Tracks

“…It is important to correctly assess the uncertainties of such plate velocities for application to many tectonic and geodynamic problems. These problems include, but are not limited to, the estimation of velocities (and associated uncertainties) of the migration of trenches (Faccenna et al, ; Schellart et al, ), resolving the motion of ultraslow‐moving plates such as Eurasia and Antarctica (Zheng et al, ), resolving motion between groups of hot spots (Wang et al, ), resolving motion of hot spots relative to the spin axis (e.g., Morgan, ; Gordon & Cape, ; Besse & Courtillot, ; Petronotis et al, ; Tarduno & Cottrell, ; Torsvik et al, ; Woodworth & Gordon, ; Zheng et al, ), and unraveling the origins of upper mantle anisotropy (e.g., Becker et al, ; Beghein et al, , ; Semple & Lenardic, ; VanderBeek & Toomey, ; Zheng et al, ). The uncertainties of such velocities are in many cases propagated from the uncertainties in hot spot trends.…”