Regional-scale advective, diffusive, and eruptive transport dynamics of CO 2 and brine within a natural analogue in the northern Paradox Basin, Utah, were explored by integrating numerical simulations with soil CO 2 flux measurements. Deeply sourced CO 2 migrates through steeply dipping fault zones to the shallow aquifers predominantly as an aqueous phase. Dense CO 2 -rich brine mixes with regional groundwater, enhancing CO 2 dissolution. Linear stability analysis reveals that CO 2 could be dissolved completely within only~500 years. Assigning lower permeability to the fault zones induces fault-parallel movement, feeds up-gradient aquifers with more CO 2 , and impedes down-gradient fluid flow, developing anticlinal CO 2 traps at shallow depths (<300 m). The regional fault permeability that best reproduces field spatial CO 2 flux variation is estimated 1 × 10 À17 ≤ k h < 1 × 10 À16 m 2 and 5 × 10 À16 ≤ k v < 1 × 10 À15 m 2 . The anticlinal trap serves as an essential fluid source for eruption at Crystal Geyser. Geyser-like discharge sensitively responds to varying well permeability, radius, and CO 2 recharge rate. The cyclic behavior of wellbore CO 2 leakage decreases with time.

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We develop a robust and simple rule‐based algorithm to autonomously simulate alluvial fan deposition and evolution under continuously developing landscape conditions without prescribing deposition locations or imposing topographic constraints. Augmented with this algorithm, landscape evolution models are capable of dynamically detecting locations of potential fan deposition by statistical measures of surface topography and fluvial dynamics, then depositing fan sediments where and when the developed conditions require. To assess the method's efficacy in depositing sediment at a mountain‐valley transition zone characterized by a transport surface that permits unobstructed exit of sediment and water, a hypothetical scenario is created that involves a frontal, normal fault. It is followed by a series of sensitivity analyses to ascertain the influence of parameters affecting fan deposition and secondary processes. Uplift (u) and precipitation significantly impact fan morphological characteristics, which are within the range of real‐world fans. Higher rates of each cause the notable expansion of the fan area except in cases of exceptionally high precipitation rates. Fan area has a power‐law relationship with most of the tested parameters, , where is erodibility (lithology), and are fluvial parameters, and is catchment area (~0.9). This study is the first showcasing fan power‐law relationships using numerical modelling. While fan area increases with precipitation, there exists a threshold beyond which fan area diminishes, and the formation of fans ceases altogether. The algorithm provides a basis for improving mechanistic understanding of fans by offering a robust platform for testing process dominance and scaling. The results demonstrate its applicability for landscape evolution simulation over a long time and broad spatial scales. We also investigate the hydrological significance of including autonomously generated alluvial fans in coupled landscape evolution—hydrology models that focus on groundwater as well as surface water hydrology.

Tectonic extension of the Earth's crust significantly alters the surface hydrology in the region by disorganizing the established connections. On the contrary, the extension also promotes the development of a new hydrologic regime by opening basins and providing topographic relief to the basins. The Rio Grande Rift (RGR) is an excellent example of an east-west tectonic extension with a large, modern axial river flowing through multiple basins, retaining the history of long-term hydrologic changes associated with the complex tectonic activities in the past. Dozens of references on the development of the gross architecture of the RGR recognized the history of the succession of the Rio Grande and its subbasins. However, there is less consensus on how surface hydrologic systems have responded to the tectonic movement in the RGR. Thus, we focus on surface hydrologic changes associated with rift tectonics and river incision. This study put forth an overarching goal: to reconstruct the history of surface hydrologic connections among basins in RGR during rift evolution. We created simple rift opening scenarios that model the Oligocene to Miocene opening of the RGR to the present. Here, we demonstrate the preliminary results of our modeling practices, and they will be further developed to reconstruct the history of hydrologic connectivity during both syn-tectonic and post-tectonic periods of the RGR.