Changyeol Lee's research

Research Interests

I focus on the geodynamical processes of temporal and spatial evolution in subduction zones such as time-evolvng subducting slab, slab buckling, and plume-slab interaction. Because these geodynamical processes are expressed as surfacial deformation and structures on the Earth, I am also intested in tectonics. I summarize my research topics described below.

Dynamics of Plume-Lithosphere

My research aims to evaluate the dynamics of Plume-Lithosphere interactions and associated geological processes through Computational Fluid Dynamic (CFD) modeling. I perform thermo-mechanical numerical experiments to develop an understanding on how dynamic interactions between mantle/wet/hybrid plumes and lithospheric mantle generate dynamic topography, delamination and draw further inferences on intra continental volcanism (Dasgupta, et al., in revision).

Mantle Wind

Mantle wind has been studied for decades but the cause and result of the mantle wind are not well understood. 2-D numerical models using a disk-shape geometry with the double subductions are formulated to clarify the cause and result of the mantle wind. The model results show that slab-driven mantle wind spontaneously occurs in the lower mantle. The subducting slabs anchored to the lower mantle owing to its high viscosity laterally sway by the swaying mantle wind. The slab dips increased and decreased by the mantle wind explain the current morphology of slab dips. (Lee et al., in preparation)

Hydrothermal Circulation

Hydrothermal circulation (HC) actively occurs in the oceanic crust in the vicinity of the Japan Trench subduction zone. HC rejuvenation (outer-rise zone before subduction, upper figure) and cessation (beneath the accretionary prism after subduction, lower figure) play significant roles in thermal structure, which impact the seafloor heat flow and demagnetization (Han et al., 2023; in preparation).

Melt Focusing Beneath NE Japan

Arc volcanoes are focused on the northeast Japan arc. This implies that the melt generated in the mantle wedge is transported and then focused beneath the arc volcanoes. Using two-dimensional numerical model, we quantitatively evaluated the partial melting and melt migration in the mantle wedge to clarify the melt focusing beneath the arc volcanoes in northeast Japan (Yoo and Lee, 2023).

Intraplate volcanoes in NE Asia

The Quaternary intraplate volcanoes in northeast Asia are sparsely distributed along the north-to-south, subparallel to the Japanese subduction zone, where the old Pacific plate subducts. These volcanoes are thought to result from the partial melting of the wet plumes that originated from the stagnant slab in the mantle transition zone. I am studying thermochemical convection, phase transition and melt transport with compaction pressure in hydrous mantle transition zone and anhydrous upper mantle, using 2-D numerical modeling (Kim et al., 2022; in preparation).

Slab Dehydration and Fluid Flow

Subducting slab experiences dehydration due to increases in pressure and temperature. The dehydrated water inserted into the mantle wedge results in flux melting, responsible for the arc volcanism. Slab dehydration and fluid flow in the subducting zones are numerically studied. The model results explain melt distribution, non-volcanic seismic tremor, and transition from subduction infancy to mature subduction through a spontaneous mechanical decoupling at the slab interface (Yoo and Lee, 2020; Lee and Kim, 2021; Lee and Kim, under review).

Volcano Clustering in NE Japan

Volcano clustering in NE Japan is thought to be releated to the 'hot fingers' in the mantle wedge. A 3-D numerical model study suggests that the hot fingers originated from the back-arc mantle strengthens the establishment of the volcano clustering. (Lee and Wada, 2017; Lee and Wada, 2021)

Cretaceous East Asian Tectonics

The tectonic history of East Asia during the Cretaceous is expressed as complicated igeneous activities such as adakite, adakitic rocks and A-type granitoids as well as basin-and-range type fault basins such as the Songliao basin. I suggested that the complicated tectonic history in East Asia during the Cretaceous was attributed to plume-plate and plume-slab interactions. (Ryu and Lee, 2017)

Time-evolving Subduction

I evaluated the effect of time-evolving subduction during the Cenozoic in the East Asian subduction zones such as Izu-Bonin-Mariana. The numerical model calculations show that other geological processes such as plume-slab interaction is relevant to the adakites or boninites in the subduction zones. (Kim and Lee, 2016)

Abukuma Adakite in NE Japan

The genesis of the 'typical' adakite erupted in the Abukuma region, NE Japan at ~16 Ma has been debated for years because the subduciton environments were not relevant to slab melting. Using 2-D and 3-D time-evolving subduction model, I show that the interaction between the infiltrated blob of the underlying hot mantle through the slab and subducting slab resulted in temporal and localized slab melting resulting in the Abukuma adakite. (Lee and Lim, 2014; Lee and Lim, 2016)

Slab Buckling

Subduction slab expriences buckling (lateral deformation resulting in stacking) due to viscosity increase across the 660 km discontinuity and phase transformation in the transition zone. I evaluated the effect of slab buckling on the seismology, structural geology and tectonics. (Lee and King, 2011)