Patterns of Plio-Pleistocene Ice Volume Variability Recorded by the Large-Magnitude Explosive Eruptions From the Kamchatka-Kurile Volcanic Arc

Marine fallout ash beds can provide continuous, time-precise records of highly explosive arc volcanism that can be linked with the climate record. An evaluation of revised Plio-Pleistocene (0–4 Myr) tephrostratigraphies from Ocean Drilling Program Sites 881, 882, and 884 confirms cyclicity of the Kamchatka-Kurile arc volcanism and a marked increase just after the intensification of the Northern Hemisphere glaciation at 2.73 Ma. The compositional constancy of the Kamchatka-Kurile volcano-magma systems through time points to external modulation of volcanic cyclicity and frequency. The stacked tephra record reveals periodic peaks in arc volcanicity at ∼0.3, ∼1.0, ∼1.6, ∼2.5, and ∼3.8 Myr that coincide with maxima of the global ice volume variability that have been linked with the amplitude modulation of the precession (0.3, 1.0 Myr) and obliquity (1.6, 2.5 and 3.8 Myr) bands. A simple model of a decreasing obliquity variance across the mid-Pleistocene Transition at constant precession variance produces an excellent correlation of ash bed cycles with the variability of global benthic δ¹⁸O (r² = 0.75), which implies that climate, and not direct orbital forcing, modulates Kamchatka-Kurile arc volcanism. The rising influence of precession variance in the Kamchatka-Kurile ash bed record after the mid-Pleistocene Transition contrasts with the dominant 100 kyr signal in the benthic δ¹⁸O global ice volume variability, which may either reflect limitations of the ash bed record or an regional rather than global influence of ice volume variability. Our results indicate that climate influences the Kamchatka-Kurile arc volcanism, which may influence climate only by feedback.