An implosive component to the source of the deep Sea of Okhotsk earthquake of 24 May 2013: Evidence from radial modes and CMT inversion

Okal, Emile A.; Saloor, Nooshin; Kirby, Stephen H.; Nettles, M.

doi:10.1016/j.pepi.2018.04.007

Cited by 5 publications

(2 citation statements)

References 68 publications

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“…Kawakatsu (1991) did not detect any significant (>10%) isotropic components for 19 large deep-focus earthquakes. However, Okal et al (2018) may have revived the discussion by reporting a 3% implosive component for the 2013 M w 8.3 Okhotsk earthquake, equivalent to a 0.9-4-m-thick transformed shear zone. Future tests of this prediction will need to consider the inaccuracy of Earth models.…”

Section: Transformational Faulting Of Metastable Olivinementioning

confidence: 99%

Mechanisms and Implications of Deep Earthquakes

Zhan

2020

Annu. Rev. Earth Planet. Sci.

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Deep earthquakes behave like shallow earthquakes but must have fundamentally different physical processes. Their rupture behaviors, magnitude-frequency statistics, and aftershocks are diverse and imperfectly dependent on various factors, such as slab temperature, depth, and magnitude. The three leading mechanisms for deep earthquakes (i.e., transformational faulting, dehydration embrittlement, and thermal runaway) can each explain portions of the observations but have potentially fundamental difficulties explaining the rest. This situation calls for more serious consideration of hypotheses that involve more than one mechanism. For example, deep earthquakes may initiate by one mechanism, but the ruptures may propagate via another mechanism once triggered. To make further progress, it is critical to evaluate the hypotheses, both single- or dual-mechanism, under conditions as close to those of real slabs as possible to make accurate and specific predictions that are testable using seismic or other geophysical observations. Any new understanding of deep earthquakes promises new constraints on subduction zone structure and dynamics. ▪ Deep earthquakes display the complex structure and dynamics of subduction zones in terms of geometry, stress state, rheology, hydration, and phase changes. ▪ Phase transformation, dehydration, and thermal runaway are the leading mechanisms for deep earthquakes, but all have major gaps or fundamental difficulties. ▪ Deep earthquakes may involve dual-mechanism processes, as hinted at by the diverse rupture and statistic properties and the break of self-similarity. ▪ Further progresses would benefit from specific and testable predictions that consider realistic slab conditions with insights from geodynamics, petrology, and mineral physics.

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Section: Transformational Faulting Of Metastable Olivinementioning

confidence: 99%

Mechanisms and Implications of Deep Earthquakes

Zhan

2020

Annu. Rev. Earth Planet. Sci.

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“…Additionally, the isotropic components of earthquake MTs are generally small (Kawakatsu, 1991;Okal et al, 2018). Therefore, catalogs usually constrain the isotropic component during the inversion to be zero and report only deviatoric MTs (Dziewonski and Woodhouse, 1983;Ekström et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

When are Non-Double-Couple Components of Seismic Moment Tensors Reliable?

Rösler¹,

Stein²,

Spencer³

2023

Seismica

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There has been considerable discussion as to how to assess when non-double-couple (NDC) components of seismic moment tensors represent real source processes. We explore this question by comparing moment tensors (MTs) of earthquakes in three global catalogs, which use different inversion procedures. Their NDC components are only weakly correlated between catalogs, suggesting that they are largely artifacts of the inversion. A monotonic decrease in the NDC components' standard deviation with magnitude indicates increased reliability of the NDC components for larger earthquakes. The standard deviation begins to decrease for large NDC components exceeding 60%, suggesting that they represent real source processes. Randomly generated NDC components with the same mean and standard deviation as in the MT catalogs only reproduce some of this decrease. Thus NDC components of large earthquakes and NDC components that exceed 60% are likely to represent real source processes.

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