At a depth of 3 km below the surface of a mine, scientists have discovered ancient water trapped between rocks. After analysis, they determined that this water is over 2 billion years old.
The Water Cycle
Water is the most abundant substance on Earth and the only one that exists in solid, liquid, and gas forms on the planet’s surface. While scientists still do not have a definitive answer to the question “Where does Earth’s water come from?”, one thing is certain: water has existed on our planet for a very long time. Fossil evidence shows that life on Earth began at least 3.5 billion years ago, and water is the origin of life.
The sun heats the water in the oceans, causing it to evaporate into the atmosphere. The rising air currents carry water vapor into the atmosphere, where it condenses into clouds when it encounters cooler temperatures. These air currents transport clouds around the globe. As cloud molecules collide and combine, they grow larger and eventually fall as rain.
The water cycle on Earth. (Photo: IvyPrep Education)
Rainwater falls as snow, accumulating into snowpacks and glaciers, causing water to freeze for thousands of years. When temperatures rise, the snow melts and flows into rivers, sometimes causing floods. A large portion of rainwater seeps into the ground, where it is retained in the soil layer and later resurfaces as groundwater. Some groundwater emerges as springs, while some is absorbed by plant roots and released as vapor through leaves.
This is the water cycle on the Earth’s surface. Therefore, scientists indicate that it is very challenging to locate the original source of water. They hypothesize that the first water on Earth may be found underground. In reality, a significant amount of water has seeped into the ground, potentially trapped there due to tectonic movements. In this case, this water could be preserved for a long time if it remains in a special low-permeability soil environment.
Discovery of 2.64 Billion-Year-Old Ancient Water
From this hypothesis, scientists from the University of Toronto decided to conduct a search in a deep underground mine. They chose the Kidd Creek Mine, which has been operational since 1966 near Timmins, Ontario, Canada. The research team spent many years searching before discovering a liquid trapped between the rocks in the mine, which they identified as ancient water.
The research team found 2.64 billion-year-old ancient water beneath Kidd Creek Mine. (Photo: Baidu)
For the first time, the research team led by geologist Barbara Sherwood Lollar visited Kidd Creek Mine in 1992. By 2013, her team had descended 2.4 km below the surface and discovered ancient water. Seven years later, they ventured down to about 3 km below ground and found another quantity of ancient water.
The researchers used radioactive isotope dating on this ancient water, combined with a comprehensive analysis of its elements, concluding that this ancient water is approximately 2.64 billion years old. Evidence from this ancient water revealed the presence of sulfate-reducing bacteria, one of the oldest forms of bacteria (dating back to around 3.5 billion years) that contributed to the sulfur cycle on Earth after life emerged.
A Taste of Ancient Water
From this clue, scientists believe that this ancient water could be the oldest water source on the planet. Due to its age, this water has a slightly murky color mixed with orange impurities. To understand the taste of this over 2 billion-year-old water, Dr. Oliver Warr decided to taste it without any sterilization methods.
Although Dr. Warr encountered no danger, he reported that this ancient water tasted very unusual—it was salty and had a foul odor. This experience can be explained as the water in the mine has undergone numerous physical and chemical reactions with surrounding materials over the past 2 billion years. A large quantity of these substances has dissolved in the water. Over time, the mineral content in this water has become abnormally high and contains various impurities, contributing to its unique taste.
The 2.64 billion-year-old ancient water is murky and mixed with orange impurities. (Photo: Baidu)
Additionally, the orange impurities in the ancient water are due to oxidation of its minerals when it was exposed to air after being brought to the surface, resulting in its peculiar color.
Comparing this ancient water with research data obtained from Mars, scientists believe that discovering this ancient sample has greatly aided their studies. Previous research has found evidence of an active groundwater system on Mars. Therefore, this discovery not only helps scientists understand the origins of water on Earth but also suggests signs of current life on the Martian surface.
Moreover, this is good news for future human space exploration as it indicates that we could easily locate necessary water supplies. For instance, astronauts may be able to discover water sources on their own rather than having to carry it along on their journeys.
