Volcanoes may erupt in a few days, Iceland is in a state of emergency! What is the connection between volcanic eruptions and climate change?
recently
Earthquakes are frequent in the southwest of Iceland
Threatened by potential underground magma eruptions
November 11 local time
A state of emergency has been declared in Iceland
Police urged residents of the relevant areas to evacuate
What is the current situation on the ground?
What is the relationship between volcanic eruptions and climate change?
What are the climate impacts?
Iceland declares a state of emergency to evacuate residents under threat of volcanic eruptions Source: Weibo@中国新闻网
About 1,400 earthquakes occurred in 24 hours
According to the Icelandic Meteorological Service, about 1,400 earthquakes occurred in 24 hours on the Reykjanes Peninsula in the southwest of the country in 24 hours from November 8 to 9 local time. Over the past half month, hundreds of small earthquakes have occurred daily in the area around Mount Torbjorn on the Reykjanes Peninsula, indicating high magma activity underground.
The southwestern region of Iceland is located at the junction of tectonic plates Source: CCTV News
According to the Icelandic Meteorological Service, the shallowest hypocenter is 3 to 3.5 kilometers deep and that the eruption could occur "within a few days".
Locals say there is a high chance of a volcanic eruption in the next few days Source: Icelandic Meteorological Agency website
According to the Icelandic Meteorological Service, the latest eruption is expected to begin at the bottom of the ocean southwest of Grindavik. In recent years, several volcanic eruptions on the Reykjanes Peninsula have been located in no-man's land, but this eruption could cause serious damage to Grindavik on the peninsula.
The town is located about 40 kilometers southwest of the capital, Reykjavík, near the Svartsengi geothermal power plant, which is the main electricity and water supplier for the 30,000 inhabitants of the Reykjanes peninsula, and has a freshwater reservoir nearby.
It will be an unprecedented volcanic eruption event
The amount of magma is amazing"
Iceland is located in the volcanically active zone of the Mid-Atlantic Ridge and is a volcanic country with high geological activity. The Reykjanes Peninsula is reportedly a volcanic and seismic hotspot in Iceland.
In March 2021, the Fagradal volcano erupted in the area, after the Fagradal volcanic system had been inactive for more than 6,000 years and the Volcanic Activity on the Reykjanes Peninsula had been dormant for 800 years.
Data schematic screen Source: CCTV News
On July 16, 2023 local time, a local volcano erupted again.
On July 16, 2023 local time, on the Reykjanes Peninsula in southwest Iceland, a volcano erupted again Source: IC photo
"There are indications that a significant amount of magma is extending from Sundhnjúkagígum in the north to Grindavik," the Icelandic Meteorological Service said. The amount of magma involved far exceeds the largest magmatic intrusion observed at the time of the eruption of the Fagradal volcano. ”
Sara Basodi, coordinator of volcanic hazards at the Icelandic Meteorological Service, said experts were surprised by the amount of magma and the speed at which it accumulated. "What we are seeing now is an unprecedented event. ”
The Chinese Embassy in Iceland also reminds Chinese citizens in Iceland to raise their safety awareness, do not stay in the Reykjanes Peninsula for a long time, try to avoid going to the Blue Lagoon and Grindavik and their surrounding areas, take necessary safety measures, prepare for earthquakes, volcanoes and their secondary disasters, avoid danger, and report to the police and contact the embassy for assistance as soon as possible in case of emergency.
How volcanic eruptions relate to climate change
Volcanic eruptions are a way for the Earth to release its internal energy. It is known that there are about 1,500 active volcanoes in the world, and about 600 volcanic eruptions have been recorded in history.
The internal causes that trigger volcanic eruptions are mainly related to the process of increased buoyancy and mobility inside the magma body.
Magma reservoirs contain enough heat and fluidity to provide enough energy for magma to reach the surface and provide material for volcanic eruptions. During the accumulation of reservoirs, it is possible to increase the heat and fluidity of the magmatic system and promote internal overpressure.
Experts interpret the internal causes of the volcanic eruption Source: CCTV News
In terms of external causes, the Earth's surface environment and climate change may be the "main culprits" that affect and trigger volcanic eruptions. When a large number of glaciers melt, the pressure exerted by the glaciers on the magma and crustal plates is reduced or transferred, causing them to become unstable.
In active volcanic areas, large-scale glacial melt can exacerbate volcanic activity. For example, in Iceland, the average eruption rate after the end of the last glacial period is as high as 100 times higher than that of the earlier cold ice period, that is, when the ice sheet is thicker, there are fewer volcanic eruptions, because the ice thickness of 1000~3000 meters delays the eruption of ice-covered volcanoes for years to decades.
Schematic map of Iceland's seabed topography Source: Planetary Institute
At the same time, sea level reduction, tidal stress changes, or precipitation changes can all become the "fuses" that trigger volcanic eruptions. Some studies have found that volcanic eruptions worldwide are 20% more in the winter than in summer in the Northern Hemisphere, possibly due to a slight drop in global sea levels as the Northern Hemisphere winter begins.
Although there are some volcanic eruptions when sea levels fall, this does not necessarily mean that rising sea levels due to climate change will dampen volcanic activity.
In addition, changes in rainfall can also cause volcanic eruptions. In 2001, the Soufrière volcano on the Caribbean island of Montserrat erupted, with heavy rains being the main cause. Heavy rains destabilized the Soufrière volcanic dome, causing it to collapse, and then a large amount of magma was released.
Volcanic gases alter the Earth's atmosphere, and the greenhouse gases in them can also trigger excessive warming and global warming, as well as slow ocean cycles, hypoxia and acidification, and may also produce volcanic winters.
Volcanic eruptions are the "cooling agent" of the earth?
Volcanic eruptions produce large amounts of ash, but volcanoes do not affect the climate through ash, because ash is relatively large particles, and these mineral particles gradually settle around the eruption site. What really affects the climate are sulfur-containing gases, including sulphur dioxide and hydrogen sulphide.
Volcanic eruptions eject sulfur-containing gases into the stratosphere, where they undergo a chemical reaction to form sulfate aerosols. The stratospheric circulation is very stable and the air moves mainly horizontally. With the "help" of the stratosphere, the aerosols formed by local volcanic eruptions can spread across the globe.
Schematic diagram of stratospheric injection
These aerosols can stay in the stratosphere for years, and they block solar radiation, helping the Earth reflect more sunlight and creating a cooling effect in the atmosphere, like a "parasol" for the Earth, causing the global average temperature to drop, also known as the "parasol" effect.
Obviously, the magnitude of the impact of volcanic eruptions on the global climate is related to the quality of sulfate aerosols entering the stratosphere. There have been 3 large-scale low-latitude volcanic eruptions since 1950:
In the 1963 eruption of Mount Argon, the eruption of Mount Elchijon in 1982 and the eruption of Mount Pinatubo in 1991, about millions or even tens of millions of tons of sulfur dioxide entered the stratosphere. All three eruptions caused global climate anomalies for the next 1 to 2 years.
In March 2021, the Fagradal volcano erupted Source: Red Star News
In addition, volcanic eruptions can trigger El Niño events, which can affect the global climate. Some studies have found that volcanic eruptions increase the likelihood of El Niño events, and are also related to the state of the ocean before the eruption.
In addition, the geographical location of the eruption is also an important factor affecting El Niño events. However, there is still a lot of controversy in the current research on this area, and further research is needed.
In addition to cooling the world, volcanic eruptions can bring significant changes in rainfall to many parts of the world. Historically, many high-intensity and large-scale drought events have been associated with volcanic eruptions. After a volcanic eruption, there is a decrease in rainfall due to a decrease in water vapor due to the decrease in surface temperature, so on a global average.
Volcanic eruptions are a double-edged sword for agriculture
Volcanoes are considered by many to be the most devastating force on earth, but there is life in the dead air, especially in agriculture.
Generally speaking, when volcanic eruptions reach a certain intensity, they naturally put three "mountains" on agricultural production in the area of influence.
Source: Beijing News International News Department
The first mountain is called "Fire". The extreme temperature of lava flowing on the surface of the earth, leaving no grass, let alone crops, is the most direct and powerful effect, and it can shatter and burn any life in its path.
The second mountain is called "Ash". Although it is called "ash", volcanic ash is not a light dust, but a huge amount of volcanic debris born in magma. A few tens of centimeters of volcanic ash can crush a building, and for crops in the grain-filling stage, even 0.1 millimeters of mulching can lead to a dead harvest.
Volcanic ash can have an impact on the respiratory system of humans and animals, and this fine particulate matter may cause heart disease, lung disease, respiratory disease, and reduce lung function.
Data schematic screen Source: CCTV Finance "First Time" column channel
The third mountain is called "Qi". Volcanoes emit high concentrations of carbon dioxide gases that can suffocate crops and livestock, and more frighteningly, the sulfur dioxide gas released by the eruptions rises into the stratosphere, forming sulfate aerosols that can persist in the stratosphere for years, affecting global climate change by scattering and absorbing solar radiation.
In addition, sulphur dioxide gas can form acid rain in the downwind area of the volcano, leading to reduced crop yields.
Of course, if you stretch the time scale a little longer, years, decades or even hundreds of years, the volcanic ash will settle and decompose to form fertile soil, which contains a large amount of phosphorus, potassium and other components needed by crops.
The volcanic lava erupted from the depths of the ocean expands the territory, cools to form hard rock, and piles up until it is exposed to the surface of the sea and becomes an island. A large amount of hot water and hot gas generated by active volcanoes is stored underground, providing a steady stream of heat for aquaculture and agricultural greenhouses.
Produced by China Meteorological News
Author: Huang Yiting, Luo Lan, Wu Peng, Ye Yihong, Tang Miao
Editor: Huang Yiting
Review: Cui Guohui Ye Haiying