Magnetic Plasma Pulses Excited By UK-Size Swirls In The Solar Atmosphere

An international team of scientists led by the University of Sheffield have discovered previously undetected observational evidence of frequent energetic wave pulses the size of the UK, transporting energy from the solar surface to the higher solar atmosphere.

Magnetic plasma waves and pulses have been widely suggested as one of the key mechanisms which could answer the long-standing question of why the temperature of the solar atmosphere rises dramatically, from thousands to millions of degrees, as you move away from the solar surface.

There have been many theories put forward, including some developed at the University of Sheffield — for example, heating the plasma by magnetic waves or magnetic plasma — but observational validation of the ubiquity of a suitable energy transport mechanism has proved challenging until now.

By developing innovative approaches, applied mathematicians at the Solar Physics and Space Plasma Research Centre (SP2RC) in the School of Mathematics and Statistics at the University of Sheffield, and the University of Science and Technology of China, have discovered unique observational evidence of plentiful energetic wave pulses, named after the Nobel laureate Hannes Alfvén, in the solar atmosphere.

These short-lived Alfvén pulses have been found to be generated by prevalent photospheric plasma swirls about the size of the British Isles, which are suggested to have a population of at least 150,000 in the solar photosphere at any moment of time.

Professor Robertus Erdélyi (a.k.a. von Fáy-Siebenbürgen), Head of SP2RC, said: “Swirling motions are everywhere in the universe, from sinking water in domestic taps with a size of centimeters, to tornadoes on Earth and on the Sun, solar jets and spiral galaxies with a size of up to 520,000 light years. This work has shown, for the first time, the observational evidence that ubiquitous swirls in the solar atmosphere could generate short-lived Alfvén pulses.

“The generated Alfvén pulses easily penetrate the solar atmosphere along cylinder-like magnetic flux tubes, a form of magnetism a bit like trees in a forest. The pulses could travel all the way upward and reach the top of the solar chromospheric layers, or, even beyond.”

Alfvén modes are currently very hard to observe directly, because they do not cause any local intensity concentrations or rarefactions as they make their journey through a magnetised plasma. They are hard to be observationally distinguished from some other types of magnetic plasma modes, like the well-known transversal magnetic plasma waves, often called kink modes.

“The energy flux carried by the Alfvén pulses we detected now are estimated to be more than 10 times higher than that needed for heating the local upper solar chromosphere,” said Dr Jiajia Liu, postdoctoral research associate.

“The chromosphere is a relatively thin layer between the solar surface and the extremely hot corona. The solar chromosphere appears as a red ring around the Sun during total solar eclipses.”

Professor Erdélyi added: “It has been a fascinating question for the scientific community for a long while — how the Sun and many other stars supply energy and mass to their upper atmospheres. Our results, as part of an exciting UK-China collaboration, involving our very best early-career scientists like Drs Jiajia Liu, Chris Nelson and Ben Snow, are an important step forward in addressing the supply of the needed non-thermal energy for solar and astrophysical plasma heating.

“We believe, these UK-sized photospheric magnetic plasma swirls are also very promising candidates not just for energy but also for mass transportation between the lower and upper layers of the solar atmosphere. Our future research with my colleagues at SP2RC will now focus on this new puzzle. “

Water Discovered For First Time In Recorded History Inside Halemaumau Crater

A small pond of water has been discovered inside the summit crater of Hawaii’s Kilauea volcano for the first time in recorded history, possibly signaling a shift to a more explosive phase of future eruptions.

The U.S. Geological Survey says that after a week of questions about a green patch inside Kilauea’s Halemaumau crater, researchers were able to confirm the presence of water on Thursday.

USGS scientist Don Swanson says the pond has grown in size over the past week.

Swanson says the bottom of the crater, which once housed Kilauea’s famed lava lake, is now below the water table and researchers believe the pond is coming from that groundwater.

Lava interacting with the water table can cause explosive eruptions.

Francisco to Strike Southern Japan Monday Night; Lekima Could Be a Threat to East Asia Late This Week

Tropical Storm Francisco is closing in on landfall in southern Japan, and that could be followed by Tropical Storm Lekima taking aim at eastern Asia later this week.

Francisco to Strike Japan First

Francisco’s top sustained winds Monday local time were about 70 mph, according to the U.S. Joint Typhoon Warning Center (JTWC).

The JTWC forecasts that Francisco will reach the southernmost of Japan’s large islands, Kyushu, Monday night into early Tuesday local time.

Francisco will then go on to make landfall in South Korea as a weakening tropical storm around Tuesday or Wednesday.

The main threat from Francisco will likely be heavy rain in parts of southern Japan, including Kyushu, Shikoku and southwestern Honshu. Flooding and landslides are possible threats, particularly in higher-terrain locations.

Heavy rain will also be a concern in eastern sections of South Korea.

Lekima a Possible Threat to Japan, Taiwan and Eastern China Later This Week

Tropical Storm Lekima has joined Francisco in the Western Pacific and could go on to impact parts of southern Japan’s Ryukyu Islands, Taiwan and eastern China later this week.

Lekima is currently centered several hundred miles south-southeast of Kadena Air Base in Okinawa.

The forecast for Lekima is still uncertain, but it’s predicted to gradually move northwestward over the next few days as it slowly intensifies. It’s possible Lekima could impact Japan’s southern Ryukyu Islands and Taiwan as a strong tropical storm late in the week ahead.

Lekima is currently forecast to make a final landfall in eastern China as tropical storm by this weekend.

Typhoons in the Northwest Pacific are equivalent to hurricanes in the Atlantic and Northeast Pacific. Both names apply to tropical cyclones that have sustained winds of at least 74 mph.

Check back to weather.com in the week ahead for additional details on the forecast for Lekima.

A Quiet Typhoon Season So Far

This year has been uncommonly calm to date for typhoon activity in the Northwest Pacific, which is normally the most active region on Earth for tropical cyclones. The only typhoon recorded in 2019 so far was Wutip, the first Category 5 super typhoon on record in February. Wutip passed south of Guam and Micronesia as a Category 4 storm, producing more than $3 million in damage.

In JTWC records that go back to 1945, only one other year, 1998, has gone from the end of February to the beginning of August without any typhoons, as noted by Dr. Phil Klotzbach of Colorado State University.

In a typical season (1981-2010), the Northwest Pacific sees about eight named storms and five typhoons by Aug. 2. This year has brought just five named storms and one typhoon so far.

The amount of accumulated cyclone energy in the Northwest Pacific – which is calculated based on how strong tropical cyclones get and how long they last – was only a little over half of average for the year as of Aug. 2, according to data compiled by Colorado State University.

Japan is accustomed to typhoons. In a typical year, three typhoons strike Japan, according to data from the Japan Meteorological Agency analyzed by nippon.com. Landfalls are most common in August, but the most destructive typhoons tend to be in September.

6.3-Magnitude Earthquake Struck Off The Coast Of Japan Near Fukushima

The earthquake rattled the same region of Japan where an earthquake triggered a nuclear power plant disaster in 2011.

Graphic shows large earthquake logo over broken earth and Richter scale reading

A 6.3-magnitude earthquake struck offshore of Japan near Fukushima on Sunday. People reported feeling the quake in the capital, Tokyo, approximately 250 km (155 miles) away.

There were no were immediate reports of damage, and no tsunami alert was issued.

The epicenter of the earthquake, which struck at 7:23 p.m. local time, was off the coast of Fukushima prefecture and measured at a depth of 50km, the Japan Meteorological Agency said.

Public broadcaster NHK TV reported that utility companies were checking on the nuclear reactors in the area.

No abnormalities were found at nuclear power plants in the region, including both Fukushima Daiichi and Daini, according to their operators, the Mainichi reported.

In 2011, Fukushima was hit by a 9.0-magnitude earthquake, which sparked a monster tsunami causing three nuclear meltdown, hydrogen explosions and radioactive contamination.

Drop Of Ancient Seawater Rewrites Earth’s History

The remains of a microscopic drop of ancient seawater has assisted in rewriting the history of Earth’s evolution when it was used to re-establish the time that plate tectonics started on the planet.

Plate tectonics is Earth’s vital — and unique — continuous recycling process that directly or indirectly controls almost every function of the planet, including atmospheric conditions, mountain building (forming of continents), natural hazards such as volcanoes and earthquakes, formation of mineral deposits and the maintenance of our oceans. It is the process where the large continental plates of the planet continuously move, and the top layers of the Earth (crust) are recycled into the mantle and replaced by new layers through processes such as volcanic activity.

Where it was previously thought that plate tectonics started about 2.7 billion years ago, a team of international scientists used the microscopic leftovers of a drop of water that was transported into the Earth’s deep mantle — through plate tectonics — to show that this process started 600 million years before that. An article on their research that proves plate tectonics started on Earth 3.3 billion years ago was published in the high impact academic journal, Nature, on 16 July.

“Plate tectonics constantly recycles the planet’s matter, and without it the planet would look like Mars,” says Professor Allan Wilson from the Wits School of Geosciences, who was part of the research team.

“Our research showing that plate tectonics started 3.3 billion years ago now coincides with the period that life started on Earth. It tells us where the planet came from and how it evolved.”

Earth is the only planet in our solar system that is shaped by plate tectonics and without it the planet would be uninhabitable.

For their research, the team analysed a piece of rock melt, called komatiite — named after the type occurrence in the Komati river near Barberton in Mpumalanga — that are the leftovers from the hottest magma ever produced in the first quarter of Earth’s existence (the Archaean). While most of the komatiites were obscured by later alteration and exposure to the atmosphere, small droplets of the molten rock were preserved in a mineral called olivine. This allowed the team to study a perfectly preserved piece of ancient lava.

“We examined a piece of melt that was 10 microns (0.01mm) in diameter, and analysed its chemical indicators such as H2O content, chlorine and deuterium/hydrogen ratio, and found that Earth’s recycling process started about 600 million years earlier than originally thought,” says Wilson. “We found that seawater was transported deep into the mantle and then re-emerged through volcanic plumes from the core-mantle boundary.”

The research allows insight into the first stages of plate tectonics and the start of stable continental crust.

“What is exciting is that this discovery comes at the 50th anniversary of the discovery of komatiites in the Barberton Mountain Land by Wits Professors, the brothers Morris and Richard Viljoen,” says Wilson.

Italy’s Etna Volcano Erupts On Sicily, Disrupting Flights

Europe’s biggest active volcano, Mount Etna, erupted early Saturday with fiery explosions and lava flows, the Italian National Institute of Geophysics and Volcanology said (INGV).

Plumes of ash prompted authorities on the island of Sicily to close the Fontanarossa and Comiso Airports in the city of Catania, local media reported.

La Repubblica newspaper said a Ryanair flight from Rome was diverted to Palermo on Friday night, while several flights were delayed from landing or taking off on Saturday.

Airport authorities said flights had returned to normal at 11 a.m. local time (0900 UTC), but stressed that there may still be disruptions and delays.

According to the INGV, the lava was spurting from one of the craters on the volcano’s desert-like southeastern face, and then traveling around 1.5 kilometers (1 mile) down a barren escarpment called the Valle del Bove (Ox Valley).

The most recent Etna activity follows an eruption in December as well as “lively spattering” recorded by the institute in June.

At 3,300 meters (10,826 feet), Etna is the largest active volcano in Europe.

‘Crystal Clocks’ Used To Time Magma Storage Before Volcanic Eruptions

The molten rock that feeds volcanoes can be stored in the Earth’s crust for as long as a thousand years, a result which may help with volcanic hazard management and better forecasting of when eruptions might occur.

Researchers from the University of Cambridge used volcanic minerals known as ‘crystal clocks’ to calculate how long magma can be stored in the deepest parts of volcanic systems. This is the first estimate of magma storage times near the boundary of the Earth’s crust and the mantle, called the Moho. The results are reported in the journal Science.

“This is like geological detective work,” said Dr Euan Mutch from Cambridge’s Department of Earth Sciences, and the paper’s first author. “By studying what we see in the rocks to reconstruct what the eruption was like, we can also know what kind of conditions the magma is stored in, but it’s difficult to understand what’s happening in the deeper parts of volcanic systems.”

“Determining how long magma can be stored in the Earth’s crust can help improve models of the processes that trigger volcanic eruptions,” said co-author Dr John Maclennan, also from the Department of Earth Sciences. “The speed of magma rise and storage is tightly linked to the transfer of heat and chemicals in the crust of volcanic regions, which is important for geothermal power and the release of volcanic gases to the atmosphere.”

The researchers studied the Borgarhraun eruption of the Theistareykir volcano in northern Iceland, which occurred roughly 10,000 years ago, and was fed directly from the Moho. This boundary area plays an important role in the processing of melts as they travel from their source regions in the mantle towards the Earth’s surface. To calculate how long the magma was stored at this boundary area, the researchers used a volcanic mineral known as spinel like a tiny stopwatch or crystal clock.

Using the crystal clock method, the researchers were able to model how the composition of the spinel crystals changed over time while the magma was being stored. Specifically, they looked at the rates of diffusion of aluminium and chromium within the crystals and how these elements are ‘zoned’.

“Diffusion of elements works to get the crystal into chemical equilibrium with its surroundings,” said Maclennan. “If we know how fast they diffuse we can figure out how long the minerals were stored in the magma.”

The researchers looked at how aluminium and chromium were zoned in the crystals, and realised that this pattern was telling them something exciting and new about magma storage time. The diffusion rates were estimated using the results of previous lab experiments. The researchers then used a new method, combining finite element modelling and Bayesian nested sampling to estimate the storage timescales.

“We now have really good estimates in terms of where the magma comes from in terms of depth,” said Mutch. “No one’s ever gotten this kind of timescale information from the deeper crust.”

Calculating the magma storage time also helped the researchers determine how magma can be transferred to the surface. Instead of the classical model of a volcano with a large magma chamber beneath, the researchers say that instead, it’s more like a volcanic ‘plumbing system’ extending through the crust with lots of small ‘spouts’ where magma can be quickly transferred to the surface.

A second paper by the same team, recently published in Nature Geoscience, found that that there is a link between the rate of ascent of the magma and the release of CO2, which has implications for volcano monitoring.

The researchers observed that enough CO2 was transferred from the magma into gas over the days before eruption to indicate that CO2 monitoring could be a useful way of spotting the precursors to eruptions in Iceland. Based on the same set of crystals from Borgarhraun, the researchers found that magma can rise from a chamber 20 kilometres deep to the surface in as little as four days.

The research was supported by the Natural Environment Research Council (NERC).