Magma flow between summit and Pu‘u ‘Ō‘ō at K̄lauea Volcano, Hawai‘i

Abstract

[1] Volcanic eruptions are often accompanied by spatiotemporal migration of ground deformation, a consequence of pressure changes within magma reservoirs and pathways. We modeled the propagation of pressure variations through the east rift zone (ERZ) of K" ılauea Volcano, Hawai'i, caused by magma withdrawal during the early eruptive episodes (1983)(1984)(1985) of the ongoing Pu'u ' " O'" o-Kupaianaha eruption. Eruptive activity at the Pu'u ' " O'" o vent was typically accompanied by abrupt deflation that lasted for several hours and was followed by a sudden onset of gradual inflation once the eruptive episode had ended. Similar patterns of deflation and inflation were recorded at K" ılauea's summit, approximately 15 km to the northwest, albeit with time delays of hours. These delay times can be reproduced by modeling the spatiotemporal changes in magma pressure and flow rate within an elastic-walled dike that traverses K" ılauea's ERZ. Key parameters that affect the behavior of the magma-dike system are the dike dimensions, the elasticity of the wall rock, the magma viscosity, and to a lesser degree the magnitude and duration of the pressure variations themselves. Combinations of these parameters define a transport efficiency and a pressure diffusivity, which vary somewhat from episode to episode, resulting in variations in delay times. The observed variations in transport efficiency are most easily explained by small, localized changes to the geometry of the magma pathway.

The 2017 Eruption of Erta 'Ale Volcano, Ethiopia: Insights Into the Shallow Axial Plumbing System of an Incipient Mid‐Ocean Ridge

“…Several key features of the Erta 'Ale shallow plumbing system show similarities to other volcanoes such as Kilauea and Mauna Loa, Hawaii, and Ambrym, Vanuatu, with the removal of melt from a summit caldera coincident with the horizontal propagation of a dike into an established rift zone (e.g., Amelung et al, 2007;Montagna & Gonnermann, 2013;Poland et al, 2014;Shreve et al, 2019). At Kilauea, a synthesis of measurements, including InSAR, GPS, tilt, and gravity, reveal a shallow magma reservoir at ∼1.5 km depth below the Halema'uma'u lava lake Bagnardi et al, 2014;Poland et al, 2014).…”

“…It has also been previously established that the shear modulus close to the summit of basaltic shield volcanoes can be significantly lower than estimates from seismic studies (Hooper et al, ). At Kilauea, Hawaii, Hooper et al () estimated the shear modulus in the upper 2.7 km to be 4.5 GPa, while Montagna and Gonnermann () use a shear modulus of 3 GPa, for modeling flow through a horizontal dike between the Kilauea summit and Pu'u'O'o. As our model is consistent with these previous findings, we suggest that a shear modulus of 4–8 GPa is applicable to Erta 'Ale, and the lava lake level is sensitive to the pressure changes in the shallow plumbing system associated with the January 2017 intrusion.…”

“…The eruption has remained active until at least June 2019. At Kilauea volcano, Hawaii, the interaction between the summit Halema'uma'u lava lake and the established Pu'u 'O'o vent in the East Rift Zone on the volcano flank has highlighted a strong interconnectivity in its shallow plumbing system (Montagna & Gonnermann, ; Neal et al, ; Patrick et al, , ), with long‐term fluctuations in the lava lake level giving an indication of the pressure state of the summit reservoir and the balance between magma influx and out‐flux (Anderson et al, ; Patrick et al, , ). The 2017 Erta 'Ale flank eruption, and potential connectivity with the lava lake, provides a similar opportunity to understand the pressure state of the shallow plumbing system at Erta 'Ale.…”

Vibrational modes of hydraulic fractures: Inference of fracture geometry from resonant frequencies and attenuation

“…In the first scenario waves have a real‐valued frequency ω . This real‐frequency model of wave propagation results in a spatial quality factor and is well suited to describe the spatial decay of perturbations that propagate along a fracture, away from a constant‐frequency source [e.g., Montagna and Gonnermann , ]. In section 6 we consider the contrasting case of a wave propagating with real‐valued wave number k .…”

“…In the first scenario waves have a real-valued frequency . This real-frequency model of wave propagation results in a spatial quality factor and is well suited to describe the spatial decay of perturbations that propagate along a fracture, away from a constant-frequency source [e.g., Montagna and Gonnermann, 2013]. In section 6 we consider the contrasting case of a wave propagating with real-valued wave number k. Such a real-wave number model of wave propagation results in a temporal quality factor and is well suited to describe the temporal decay of resonant modes of a finite-length hydraulic fracture.…”