Which phenomenon is directly related to the increase in sea levels?

The phenomenon directly related to the increase in sea levels is glacial melting. As global temperatures rise due to climate change, glaciers and ice sheets in polar regions and mountainous areas are melting at an accelerated rate. This melting contributes additional water to the oceans, resulting in higher sea levels.

When glaciers melt, they release stored freshwater into the ocean, which increases the overall volume of water. Additionally, the thermal expansion of seawater as it warms also contributes to rising sea levels. The combination of these factors is a significant driver of current sea level rise, making glacial melting the primary phenomenon associated with this issue.

In contrast, the other choices do not have a direct impact on sea levels. The formation of clouds involves moisture but is not a contributor to sea level changes. Increased ocean salinity results from evaporation and freshwater influx but does not inherently raise sea levels. More frequent earthquakes may cause localized changes in land elevation but are not a consistent factor associated with overall sea level rise.