Water has extraordinary significance for humans, especially freshwater. It can be said that many corners of daily life, including clothing, food, housing, and transportation, require the support of freshwater. However, even though 71% of the Earth's surface is covered by water, the actual freshwater that can meet the needs of human life activities only accounts for 2.53% of the total water volume, which is very precious. Therefore, most developed and developing countries around the world are conducting research on the development and protection of freshwater resources.



Recently, American media reported a news from the journal Scientific Reports, stating that scientists from Columbia University and Woods Hole Oceanographic Institution spent ten days using a research vessel towing electromagnetic sensors to discover a "freshwater ocean" hidden on the seabed. And this discovery may give people the opportunity to access isolated freshwater resources, as emphasized in the report: "It may be an important water source in other parts of the world

Undoubtedly, this achievement is worth the excitement of researchers and even the people. However, as the "hero" who silently contributed behind this discovery, should the development of sensor technology also be praised?

In fact, using electromagnetic waves to search for freshwater resources itself is not uncommon. There have been news of using electromagnetic waves to search for groundwater a long time ago. But unlike searching for groundwater, exploring freshwater resources in the ocean faces more stringent environmental factors. Firstly, the ocean is a saltwater environment, and in order to find freshwater resources in this environment, it is necessary to accurately measure the propagation mode of electromagnetic waves in both freshwater and saltwater, which poses a huge challenge to the accuracy of sensors. In addition, the ocean itself is a humid and variable environment, and seawater has a certain degree of corrosiveness. If the sealing and overall firmness of the sensor are not good enough, it is highly likely to be damaged due to ship bumps, long-term work, or seawater splashing.

In other words, this success cannot be separated from the significant development of electromagnetic sensors in terms of accuracy and quality over the years.

However, we cannot only focus on immediate benefits and ignore the actual long-term development. Although humans have discovered the distribution of "freshwater oceans" on the seabed, if not used properly, the result is often human caused disasters.

Simply put, the first step is to have a preliminary understanding of the surrounding water quality and geology, establish a preliminary plan through instrument measurement, and facilitate subsequent mining; Secondly, it is important to ensure the maturity of underwater freshwater extraction technology, ensuring that this technology does not cause fluctuations in the geological structure of the seabed, nor does it cause marine pollution; The next step is a complete mining plan to ensure that there is no overexploitation of underwater freshwater resources.

Of course, in terms of water resources itself, perhaps underground freshwater resources are not the appropriate direction. In fact, throughout history, surface freshwater and shallow groundwater have been the main water resources for people, nurturing the development of human civilization. In other words, if water resources had not been polluted, the scarcity of freshwater resources may not have developed to this day. So the editor believes that while studying the "freshwater ocean", how to further protect existing water resources, improve water source environment, and control water pollution are the topics that need to be emphasized in the direction of water resource utilization.