Spatial variation of in situ stress at shallow depth in South Korea

Kang, Minzy; Chang, Chandong; Bae, Seongho; Park, Chan

doi:10.1007/s12303-023-0002-0

Cited by 1 publication

(1 citation statement)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6 b). Another study on the in situ stress field in South Korea, based on borehole hydraulic fracturing tests, has also revealed that the prevailing stress regime changes with depth from reverse faulting (0–200 m depth), to transitional region (200–500 m), and strike-slip faulting (below 500 m) 49 . This vertical change in stress condition can be interpreted in terms of the greater decrease in vertical stress due to the greater release of overburden loading compared with the decrease in σ Hmin closer to the surface.…”

Section: Discussionmentioning

confidence: 98%

Near-surface termination of upward-propagating strike-slip ruptures on the Yangsan Fault, Korea

Cheon

Kim

Choi

et al. 2023

Sci Rep

View full text Add to dashboard Cite

We present a new example of the termination of strike-slip paleoearthquake ruptures in near-surface regions on the Yangsan Fault, Korea, based on multi-scale structural observations. Paleoearthquake ruptures occur mostly along the boundary between the inherited fault core and damage zone (N10–20°E/> 75°SE). The ruptures propagated upward to the shallow subsurface along a < 3-cm-wide specific slip zone with dextral-slip sense, along which the deformation mechanism is characterized mainly by granular flow in near-surface region. The ruptures either reach the surface or are terminated in unconsolidated sediment below the surface. In the latter case, the rupture splays show westward bifurcation, and their geometry and kinematics show a change to NNW-strike with low-angle dip and dextral-reverse oblique-slip sense in the strata. We suggest that the upward termination of the contractional strike-slip ruptures is controlled by the inherited fault geometry that is unfavorable with respect to the stress field (ENE–WSW σHmax) at basement depths in terms of movement on the fault, and the lack of extension of the fault into shallow subsurface; a depth-dependent change in stress from σHmax > σv > σHmin to σHmax > σHmin > σv at depth of a ~ 200 m; and the physical properties of unconsolidated sediment, which have low inter-granular cohesion, resulting in distributed deformation.

show abstract

Section: Discussionmentioning

confidence: 98%