Studies have found that the gradual melting of Antarctic icebergs from the melting continents may be the inducement that plunged the earth into a new ice age.
Researchers at Cardiff University reconstructed past weather conditions and identified tiny fragments of Antarctic rocks that fell into the sea as part of a study aimed at understanding how the ice age began.
Over the past 1.6 million years, changes in the ice age have been made by periodically changing the speed of the Earth’s solar orbit-changing the amount of solar radiation reaching the surface.
However, prior to this study, there was little understanding of how solar changes caused by small changes in the orbit changed the Earth’s climate so drastically.
They found that melting icebergs gradually transferred freshwater from the south to the Atlantic Ocean by further melting from Antarctica, which caused changes in ocean circulation and plunged the earth into a cold period, which triggered the ice age.
The researchers warned that the impact of man-made carbon dioxide emissions may make the Southern Ocean too warm to reach the Antarctic icebergs, thus ending the 1
Studies have found that the gradual melting of Antarctic icebergs from the melting continents may be the inducement that plunged the earth into a new ice age.Stock Images
The research team found that when the Earth’s solar orbit changes, the Antarctic iceberg gradually melts northward, reducing solar energy to the surface.
In their research, the research team proposed that when the earth’s orbit around the sun is correct, the Antarctic icebergs begin to gradually move away from the Antarctic and melt.
This led to the transfer of large amounts of fresh water from the southern ocean to the Atlantic Ocean.
As the Southern Ocean became saltier and the North Atlantic became fresher, large-scale ocean circulation patterns began to change dramatically, releasing carbon dioxide into the atmosphere and reducing the so-called greenhouse effect.
The research team said that this in turn pushed the earth into an ice age, and he reconstructed past weather conditions, including melting icebergs and discovering tiny Antarctic rock fragments that fell into the sea.
The rock fragments were obtained from sediments recovered from the 1.6 million-year-old International Ocean Discovery Program (IODP).
Studies have found that these sediments, known as “ice raft wrecks,” seem to have been causing changes in the deep-sea circulation, which are reconstructed by the chemical action of tiny deep-sea fossils called foraminifera.
By melting icebergs to track changes in salt and fresh water over time, the team found tiny fragments of Antarctic rocks that were deposited in the high seas
The team also used a new climate model simulation to test its hypothesis and found that icebergs can move large amounts of fresh water.
The lead author of the study Aidan Starr (Aidan Starr) said they were surprised to find that there was a link between melting icebergs and ocean circulation during each ice age of the past 1.6 million years.
He said: “It is speculated that Antarctica and Antarctica play such a leading role in the global climate, but it is very exciting to see this so clearly in the geological evidence.”
Professor Ian Hall, co-author and co-chief scientist of the IODP expedition study from Cardiff, said the findings provided a “missing link” to the history of the Ice Age.
Icebergs from Antarctica entered the Southern Ocean without melting and transferred fresh water from the ocean to the Atlantic Ocean, triggering changes in ocean circulation and cooler periods
In the past three million years, the earth has often fallen into ice ages, but it is currently in a period of rising interglacial temperatures.
However, due to the impact of man-made CO2 emissions on the world, this situation may not happen again.
Researchers believe that the natural rhythm of the ice age cycle may be disturbed because the South Ocean may become too hot and the Antarctic icebergs cannot go far enough to trigger the changes in ocean circulation required to start the ice age.
Professor Hall believes that these results can be used to understand how our climate will respond to man-made climate change in the future.
Hall said that similar to what we have observed, the mass loss caused by iceberg activity in the Antarctic continent and the Southern Ocean has increased due to the warming associated with current human greenhouse gas emissions.
He said: “Our research emphasizes the importance of understanding the trajectory and melting patterns of icebergs for the strongest predictions of future impacts on ocean circulation and climate.”
Professor Grant Bigg, a professor in the Department of Geography at the University of Sheffield, simulated the iceberg model, which he said is a breakthrough modeling in the climate model.
Adding it is essential to “identify and support the hypothesis of ice cream fragments that caused the melting of Antarctic icebergs that started the glacial cycle.”
The research results were published in the journal Nature.
Atlantic circulation plays a key role in regulating global climate
The circulation of the Atlantic Ocean plays a key role in regulating the global climate.
This is due to the constantly moving deep-water circulation system (often called the global ocean conveyor belt) transporting warm, salty Gulf Stream water to the North Atlantic, where it releases heat to the atmosphere and warms Western Europe.
The colder water then sinks into the depths, flows to Antarctica, and finally circulates back to the Gulf Stream.
The circulation of the Atlantic Ocean plays a key role in regulating the global climate
This movement is driven by the hot salt current (a combination of temperature and salt).
It takes 1,000 years for water to complete a continuous journey around the world.
Researchers believe that as the North Atlantic begins to warm up towards the end of the Little Ice Age, fresh water disrupts the system, known as the Atlantic Meridian Overturning Cycle (AMOC).
Arctic sea ice and ice caps and glaciers around the Arctic began to melt, forming a large amount of natural fresh water into the North Atlantic.
The influx of a large amount of fresh water desalinates the surface seawater, making it lighter and reducing its sinking capacity, thus slowing down the operating speed of the AMOC system.
Researchers found that since 1950, AMOC has declined faster due to recent global warming.