Final answer:
The net change in elevation of the ocean's surface from 1 PM to 7 PM cannot be determined from the provided information. However, longer-term changes in sea level are influenced by climate change, with an increased rate of sea level rise observed since 1993 due to thermal expansion and melting ice.
Step-by-step explanation:
The question does not provide enough information to determine the net change in elevation of the ocean's surface from 1 PM to 7 PM. Sea level change over short timeframes like a few hours is primarily influenced by tides, which are not referenced in the question. However, based on the provided references, we can discuss longer-term sea level changes caused by climate change and temperature increases.
For example, since 1993, the rate of sea level rise has increased to between 2.9 and 3.4 mm per year. Sea level rises due to thermal expansion caused by warming oceans and increased melting of land ice, such as glaciers and polar ice caps. This contributes additional water to the oceans. Future projections indicate that with a substantial increase in global temperatures, sea levels could rise up to several meters.