Uncertainties in Trends of Young Hot Spot Tracks

Abstract

Uncertainties in trends of hot spot tracks are investigated using a relationship between trend uncertainty and the mapview dimensions of a hot spot track. Prior estimates of Δt (the time span averaged in estimating the trend of a hot spot track), combined with an observed average track width of σwidth = 33 km, indicate that uncertainties in track trend are larger than estimated before, especially for hot spot tracks on slow‐moving lithosphere. Measured values of σwidth of different hot spot tracks differ insignificantly from one another. Track widths show no significant differences between oceanic and continental tracks and between tracks of deep plumes and tracks of shallow plumes. We find that motion between groups of hot spots on different plates is slow. Nominal speeds vary from 0 to 6 mm/a with a lower bound of zero and upper bounds of 4 to 13 mm/a for the eight best constrained hot spot groups.

Observational Test of the Global Moving Hot Spot Reference Frame

“…Doubrovine et al (2012) estimate the locations as a function of time of 44 hot spots (their Table S6). Thirty eight of the hot spots modeled by Doubrovine et al (2012) correspond to 41 of the 56 trends of hot spot tracks adopted by Wang et al (2019). Thus, we use the observed trends of these 41 tracks ( Figure 1 and Table S1 in the supporting information) to test the predictions of the GMHRF.…”

“…We adopt the current hot spot locations and current trends from Morgan and Morgan (2007). The uncertainties in trends are calculated objectively using hot spot track length and width (Gripp & Gordon, 2002;Wang et al, 2019).…”

“…The fitting function we use is similar to those used by Gripp and Gordon (2002) and Wang et al (2019). We take the sum-square normalized misfit to N hot spot trends to be…”

“…where α i is the difference in angle between the ith observed and ith calculated trend and σ i is the 1-sigma uncertainty of the ith observed trend (Wang et al, 2019). 10.1029/2019GL083663…”

“…He further proposed that plumes of hot rock rise up from deep in the mantle and are the cause of hot spots at the surface, which had been proposed by Wilson (1963) to explain the origin of chains of seamounts and islands, such as the Hawaiian island chain. Since Morgan's (1971Morgan's ( , 1972 work, hot spot tracks have been widely used to estimate plate motion relative to the deep mantle, especially for geologically current plate motions (e.g., Chase, 1978;Gripp & Gordon, 1990, 2002Minster et al, 1974;Minster & Jordan, 1978;Morgan & Morgan, 2007;Wang et al, 2017Wang et al, , 2018Wang et al, , 2019.…”