Earth is a beautiful planet in the solar system, and it is currently the only planet with a significant amount of water on its surface. The water on the surface of Earth has combined to form vast oceans. The surface of the Earth can be divided into two parts: the seas and the land, thus forming two main ecosystems: the marine ecosystem and the terrestrial ecosystem.
The total surface area of the Earth is about 510 million km², with the ocean area occupying the majority. The total area of the oceans on Earth is approximately 361 million km², accounting for 71% of the total surface area of the Earth, while the total land area is only 149 million km², making up about 29% of our planet’s total area.
If the ratio of the land area and ocean area of the Earth were reversed, meaning the land area would increase to 361 million km² and the ocean area would shrink to 149 million km², then the geographical environment of the Earth would certainly undergo significant changes.
If the total amount of water in the oceans on Earth remains the same as it is now, it is certain that the average depth of the oceans would increase significantly due to the reduction in surface area.
Currently, the average depth of the ocean in the region is about 3,795 meters. If the surface area of the ocean decreases, the average depth of the ocean would be around 9,194 meters, which means that the depths of many ocean floors would be even deeper than the current average depth of the Mariana Trench. And obviously, the exploration and study of the ocean floor by humans would face many more difficulties compared to now.
The Mariana Trench, also known as the Mariana Abyss or the Mariana Trough, is the deepest ocean trench known, and its deepest point is the deepest point in the Earth’s crust. It is located at the bottom of the northwestern Pacific region, east of the Mariana Islands. The deepest point is located at coordinates 11°21′ North and 142°12′ East. The trench extends close to Japan. This trench is a boundary where two tectonic plates meet, being an area of subduction where the Pacific Plate is being pushed down beneath the Philippine Plate. The trench is about 2,550 km long but has an average width of only about 69 km. The bottom of this trench is much deeper below sea level than the peak of Mount Everest above sea level. The maximum depth of this trench is measured at 11,034 meters below sea level according to the latest measurements. Taking into account the latitude of the Mariana Trench and the bulge at the equator of the Earth, the Mariana Trench is located about 6,366.4 km from the Earth’s center. The Arctic Ocean, with a depth of only about 4-4.5 km, is actually about 6,352.8 km from the Earth’s center, which is closer to the Earth’s center than the deepest point of the Mariana Trench by 13.6 km.
The surface area of land on Earth being expanded also means that the area of all countries in the world would be significantly enlarged, with the land area of each country potentially being expanded by up to 2.4 times. For example, the current land area of Russia is 17.09 million km², and when expanded by 2.4 times, it becomes 41.06 million km².
When the area of the ocean becomes smaller and the area of land becomes larger, it is estimated that the number of coastal countries will decrease, while the number of landlocked countries will increase, and the total length of global coastlines may become shorter.
Saltwater covers an area of about 360,000,000 km² and is generally divided into several major oceans and smaller seas, with the oceans accounting for approximately 71% of the surface and 90% of the biosphere. 97% of the water on Earth belongs to the oceans, and oceanographers have stated that over 95% of the world’s oceans remain unexplored. The total capacity of the oceans is about 1.35 billion km³ with an average depth of nearly 3,700 m.
From a natural geographical perspective, due to the reduction of ocean area, the amount of water vapor evaporating into the atmosphere due to solar radiation will decrease, and as a result, the total amount of water in the atmosphere will also decrease, leading to a reduction in total global precipitation.
This means that many areas on land will have climates similar to that of Central Asia today – inland areas far from the sea with sparse rainfall.
Due to the large land area, the number of deep inland areas will significantly increase. It would be nearly impossible to have ocean water vapor in these inland areas. The surface of the land would be dominated by natural desert belts. Therefore, an increase in land area is not necessarily a good thing, as many regions may become desertified and unsuitable for human habitation.
Desertification is the phenomenon of land degradation in arid regions caused by human activities and climate change. The trend of desertification has recently accelerated worldwide partly due to population pressure and the demand for agriculture and livestock. The biggest impact of desertification is the loss of biodiversity and the decline in land productivity.