Soru

### Models of Venusian Resurfacing

The surface of Venus has remarkably few impact craters, and they are randomly distributed across the planet. This indicates that the surface is geologically young, with an estimated age of $300$ to $600\text{ million years}$. Two models have been proposed to explain how the Venusian surface was renewed.

Model 1 (Catastrophic Resurfacing)
Venus has a single, thick, rigid lithospheric plate. Because Venus lacks plate tectonics, internal radiogenic heat cannot be continuously released. Instead, heat accumulates in the mantle, causing it to warm and soften. Eventually, the hot mantle weakens the overlying lithosphere, causing the entire lithosphere to founder and sink into the mantle in a catastrophic, planet-wide event. This is accompanied by massive global volcanism that completely covers the planet in lava, destroying all pre-existing craters within a short span of $10$ to $50\text{ million years}$. Following this event, the lithosphere cools and solidifies again, remaining geologically inactive for hundreds of millions of years until the next cycle.

Model 2 (Gradual Resurfacing)
Venus does not experience planet-wide catastrophes. Instead, it undergoes steady, ongoing tectonic and volcanic activity that is localized. Plumes of hot mantle material rise continuously, causing localized volcanic eruptions and rifting that renew small portions of the surface at any given time. Over hundreds of millions of years, these smaller, scattered volcanic events resurface the entire planet incrementally. While this process is slow and continuous, it produces a spatially random distribution of craters because new craters are constantly forming while older craters are randomly covered by localized lava flows.

Based on the models described, match each scientific assertion on the left with the model(s) that support it on the right.