UPDATE: Cyclone Idai May Be ‘One of the Worst’ Disasters in the Southern Hemisphere

Officials with global aid groups and in Mozambique, where the storm hit hardest, are only beginning to reckon with its destruction. Potentially 1.7 million people were in the direct path of the cyclone, the United Nations estimated on Tuesday, and rain is forecast to continue in parts of the region for several days.

Cyclone Idai, the storm that has killed hundreds of people, submerged homes and battered cities in southeastern Africa, may prove to be one of the worst weather-related disasters ever in the Southern Hemisphere, a United Nations official said on Tuesday.

Herve Verhoosel, a spokesman for the United Nations World Food Program, said in an interview that the agency’s workers had described seeing “water and water for miles and miles” – flooding so severe it resembled an inland ocean where homes and towns had stood.

The situation remained dire, he said, for potentially hundreds of thousands of people in need of food, clean water and evacuation.

What happened

Cyclone Idai made landfall last Thursday into Friday on the coast of Southeast Africa, striking Mozambique, Malawi and Zimbabwe. (Like hurricanes and typhoons, a cyclone is a low-pressure circular storm system with winds greater than 74 miles per hour, each termed according to where it forms.)

In addition to the 1.7 million people potentially affected in Mozambique, the World Food Program estimated that 920,000 people were affected in Malawi and 15,000 in Zimbabwe.

Because of the flooding, most roads and bridges are closed, and many regions have no power – shutting down communications and airports that could be used to bring in supplies and evacuate people. Mr. Verhoosel said that people were stranded on rooftops and climbing into trees to escape the water, and were without food, safe water or medicine.

President Filipe Nyusi of Mozambique said in a televised statement on Tuesday that the cyclone had killed more than 200 people, Reuters reported. In Zimbabwe, state news media reported that more than 100 people had died.

Earlier Mr. Nyusi had reportedly said he feared as many as 1,000 people could be found dead. Mr. Verhoosel said the death toll was expected to climb into the hundreds.

“If these reports, these fears, are realized, then we can say that this is one of the worst weather-related disasters – tropical cyclone-related disasters…Pin the Southern Hemisphere,” said Clare Nullis, a spokeswoman for the World Meteorological Organization, citing the president’s figure.

__________________

Science Of Cycles keeps you tuned-in and knowledgeable of what we are discovering, and how some of these changes will affect our communities and ways of living.

 

Shiveluch Volcano (Kamchatka, Russia): Continuing Activity, Frequent Small Glowing Avalanches

The activity at the volcano has been a bit lower during the past days, although overall similar to the past weeks. The lava dome continues to grow steadily.

During the past nights, we observed frequent, but mostly small glowing avalanches from the active dome as well as small ash emissions and intense steaming. The upper third of the dome, now over 800 m high, seems to be active with many incandescent spots visible.

No larger events (pyroclastic flows traveling beyond the base of the cone or explosions with significant ash emissions) have been observed since our arrival on 16 Mar. According to the volcano observatory, internal activity remains elevated, and the risk of a major dome collapse continues to increase.

Never Seen So Much Rain’: Zimbabweans Struggle With Storm floods

Chipinge, Zimbabwe – The death toll from Cyclone Idai continues to rise as southern African countries struggle to deal with the devastating aftermath of the torrential downpours.

The powerful storm has killed at least 64 people in Zimbabwe in recent days, government officials say, while in neighbouring Mozambique the death toll has jumped to 48.

Idai made landfall in Mozambique on Thursday evening before proceeding to Zimbabwe and Malawi, causing flash floods, wrecking infrastructure and leaving communities without electricity.

More than a million people have been affected, including tens of thousands who have been displaced, according to the International Federation of Red Cross and Red Crescent Societies.

In Zimbabwe’s Eastern Highlands, the heavy rains had died out by Sunday – but only after causing widespread destruction.

In Chipinge, an eastern town some 450km southeast of the capital, Harare, transport links were cut off after a road was damaged due to water pressure.

A bus carrying passengers bound for Harare was stuck in a mush of soft tar and mud. A few small cars managed to bypass the sludge when volunteers and soldiers laid down a makeshift path made of wooden planks.

Transport engineers told Al Jazeera that the works to repair the damaged road could take up to a day, leaving locals trying to leave the flooded town stranded.

Gladys Nyandoro, a 58-year-old Chipinge resident whose home had been flooded, said she would seek alternative transport to continue her journey with her son to a temporary shelter in Harare.

“I could only leave with a few clothes, but my house is full of water. I have never seen so much rain since we moved back here,” she said of her husband’s communal home.

“I just want to go back to Harare; this area is too much for me.”

Anesu Chitepo, a 22-year-old shopkeeper, said his grocery store had been affected by erratic power outages caused by the heavy rains.

“We can’t be happy to think this rain is a blessing when everything it touches is destroyed,” he said. “This will only bring us more trouble, than the real water we wanted.”

Zimbabwe’s government has declared the torrential storm a disaster and dispatched members of the military and national youth service to help evacuate stranded villagers.

Meanwhile, the country’s Civil Protection Unit has been using helicopters to gain access to the remote town of Chimanimani, on the northeastern border with Mozambique.

Local aid groups have yet to access the area where dozens are thought to be missing and hundreds more are in urgent need of humanitarian aid.

According to Joshua Sacco, a local member of parliament, all four bridges leading to the mountainous town have been damaged.

“We have people stranded in this area, but the access roads to this area have landslides,” he said.

“There is nothing, we don’t have any road accessible,” added Sacco.

“The best form of help we need is an excavator or a grader to clear the roads.”

The cyclone has brought torrential rains and winds thought to be worst in decades since Cyclone Eline struck the region in 2000.

Astronomers Discover 83 Supermassive Black Holes In The Early Universe

Astronomers from Japan, Taiwan and Princeton University have discovered 83 quasars powered by supermassive black holes in the distant universe, from a time when the universe was less than 10 percent of its present age.

“It is remarkable that such massive dense objects were able to form so soon after the Big Bang,” said Michael Strauss, a professor of astrophysical sciences at Princeton University who is one of the co-authors of the study. “Understanding how black holes can form in the early universe, and just how common they are, is a challenge for our cosmological models.”

This finding increases the number of black holes known at that epoch considerably, and reveals, for the first time, how common they are early in the universe’s history. In addition, it provides new insight into the effect of black holes on the physical state of gas in the early universe in its first billion years. The research appears in a series of five papers published in The Astrophysical Journal and the Publications of the Astronomical Observatory of Japan.

Supermassive black holes, found at the centers of galaxies, can be millions or even billions of times more massive than the sun. While they are prevalent today, it is unclear when they first formed, and how many existed in the distant early universe. A supermassive black hole becomes visible when gas accretes onto it, causing it to shine as a “quasar.” Previous studies have been sensitive only to the very rare, most luminous quasars, and thus the most massive black holes. The new discoveries probe the population of fainter quasars, powered by black holes with masses comparable to most black holes seen in the present-day universe.

The research team used data taken with a cutting-edge instrument, “Hyper Suprime-Cam” (HSC), mounted on the Subaru Telescope of the National Astronomical Observatory of Japan, which is located on the summit of Maunakea in Hawaii. HSC has a gigantic field-of-view — 1.77 degrees across, or seven times the area of the full moon — mounted on one of the largest telescopes in the world. The HSC team is surveying the sky over the course of 300 nights of telescope time, spread over five years.

The team selected distant quasar candidates from the sensitive HSC survey data. They then carried out an intensive observational campaign to obtain spectra of those candidates, using three telescopes: the Subaru Telescope; the Gran Telescopio Canarias on the island of La Palma in the Canaries, Spain; and the Gemini South Telescope in Chile. The survey has revealed 83 previously unknown very distant quasars. Together with 17 quasars already known in the survey region, the researchers found that there is roughly one supermassive black hole per cubic giga-light-year — in other words, if you chunked the universe into imaginary cubes that are a billion light-years on a side, each would hold one supermassive black hole.

The sample of quasars in this study are about 13 billion light-years away from the Earth; in other words, we are seeing them as they existed 13 billion years ago. As the Big Bang took place 13.8 billion years ago, we are effectively looking back in time, seeing these quasars and supermassive black holes as they appeared only about 800 million years after the creation of the (known) universe.

It is widely accepted that the hydrogen in the universe was once neutral, but was “reionized” — split into its component protons and electrons — around the time when the first generation of stars, galaxies and supermassive black holes were born, in the first few hundred million years after the Big Bang. This is a milestone of cosmic history, but astronomers still don’t know what provided the incredible amount of energy required to cause the reionization. A compelling hypothesis suggests that there were many more quasars in the early universe than detected previously, and it is their integrated radiation that reionized the universe.

“However, the number of quasars we observed shows that this is not the case,” explained Robert Lupton, a 1985 Princeton Ph.D. alumnus who is a senior research scientist in astrophysical sciences. “The number of quasars seen is significantly less than needed to explain the reionization.” Reionization was therefore caused by another energy source, most likely numerous galaxies that started to form in the young universe.

The present study was made possible by the world-leading survey ability of Subaru and HSC. “The quasars we discovered will be an interesting subject for further follow-up observations with current and future facilities,” said Yoshiki Matsuoka, a former Princeton postdoctoral researcher now at Ehime University in Japan, who led the study. “We will also learn about the formation and early evolution of supermassive black holes, by comparing the measured number density and luminosity distribution with predictions from theoretical models.”

Based on the results achieved so far, the team is looking forward to finding yet more distant black holes and discovering when the first supermassive black hole appeared in the universe.

Probability Of Catastrophic Geomagnetic Storm Lower Than Estimated

Three mathematicians and a physicist from the Universitat Autònoma de Barcelona (UAB), the Mathematics Research Centre (CRM) and the Barcelona Graduate School of Mathematics (BGSMath) propose a mathematical model which allows making reliable estimations on the probability of geomagnetic storms caused by solar activity.

The researchers, who published the study in the journal Scientific Reports (of the Nature group) in February, calculated the probability in the next decade of a potentially catastrophic event for the Earth’s telecommunications, such as the one which occurred between the end of August and beginning of September 1859, known as the “Carrington Event.” That year, astronomer Richard C. Carrington observed the most powerful geomagnetic storm known up to date. According to this new research, the probability of a similar solar storm occurring in the following decade ranges from 0.46% to 1.88%, far less than the percentage estimated before. “In 2012, the results reported in scientific literature estimated the probability to be around 12%, ten times more than our more pessimistic estimation,” David Moriña, first author of the study and postdoctoral researcher explains. “Our model is more flexible than previous ones and it also includes the model used for the previous estimations as a specific case,” Moriña adds.

The intensity of solar surface perturbations such as flares and coronal mass ejections affecting the Earth’s magnetosphere has been measured since 1957 using the “Dst” index, which centralises the values collected every hour in stations located across the globe. Normally, the value of this parameter ranges from -20 to +20 nT (nanoteslas, one billionth of a tesla unit; a tesla unit can be compared to the magnetic flux density generated by a powerful loudspeaker). It is estimated that the Dst index associated with the Carrington Event had a value of approximately -850 nT.

Geomagnetic storms are responsible for spectacular phenomena such as the aurora borealis observed at the Earth’s highest latitudes, which depending on their intensity can interfere drastically with different aspects of human activity. Examples of severe disruptions occurring in past decades are the interruption of electrical and navigation systems, and satellite communications. “In Carrington’s time, the only infrastructure affected was the global telephone network,” says one of the authors of the study, mathematician Isabel Serra. “Now, a storm of such intensity could have catastrophic effects on our society. According to a 2013 study conducted by the Lloyd’s of London insurance company and Atmospheric and Environmental Research, the duration of these effects could last longer than a year, and costs could rise to 2.5 trillion dollars. These are number that should make us think,” Isabel Serra insists.

“A probability close to 2% which is what we have calculated for a highly intense storm should not be looked over if we take into account the consequences of such an event,” says Professor Pere Puig, one of the authors of the paper. “Governments should have action protocols to react to such disasters, in order to inform and calm the population left without electrical energy and no way to communicate. We cannot forget that there will be very little time of reaction before the unforeseen arrival of this type of storm.”

What Scientists Found After Sifting Through Dust In The Solar System

Just as dust gathers in corners and along bookshelves in our homes, dust piles up in space too. But when the dust settles in the solar system, it’s often in rings. Several dust rings circle the Sun. The rings trace the orbits of planets, whose gravity tugs dust into place around the Sun, as it drifts by on its way to the center of the solar system.

The dust consists of crushed-up remains from the formation of the solar system, some 4.6 billion years ago — rubble from asteroid collisions or crumbs from blazing comets. Dust is dispersed throughout the entire solar system, but it collects at grainy rings overlying the orbits of Earth and Venus, rings that can be seen with telescopes on Earth. By studying this dust — what it’s made of, where it comes from, and how it moves through space — scientists seek clues to understanding the birth of planets and the composition of all that we see in the solar system.

Two recent studies report new discoveries of dust rings in the inner solar system. One study uses NASA data to outline evidence for a dust ring around the Sun at Mercury’s orbit. A second study from NASA identifies the likely source of the dust ring at Venus’ orbit: a group of never-before-detected asteroids co-orbiting with the planet.

“It’s not every day you get to discover something new in the inner solar system,” said Marc Kuchner, an author on the Venus study and astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “This is right in our neighborhood.”

Another Ring Around the Sun

Guillermo Stenborg and Russell Howard, both solar scientists at the Naval Research Laboratory in Washington, D.C., did not set out to find a dust ring. “We found it by chance,” Stenborg said, laughing. The scientists summarized their findings in a paper published in The Astrophysical Journal on Nov. 21, 2018.

They describe evidence of a fine haze of cosmic dust over Mercury’s orbit, forming a ring some 9.3 million miles wide. Mercury — 3,030 miles wide, just big enough for the continental United States to stretch across — wades through this vast dust trail as it circles the Sun.

Ironically, the two scientists stumbled upon the dust ring while searching for evidence of a dust-free region close to the Sun. At some distance from the Sun, according to a decades-old prediction, the star’s mighty heat should vaporize dust, sweeping clean an entire stretch of space. Knowing where this boundary is can tell scientists about the composition of the dust itself, and hint at how planets formed in the young solar system.

So far, no evidence has been found of dust-free space, but that’s partly because it would be difficult to detect from Earth. No matter how scientists look from Earth, all the dust in between us and the Sun gets in the way, tricking them into thinking perhaps space near the Sun is dustier than it really is.

Stenborg and Howard figured they could work around this problem by building a model based on pictures of interplanetary space from NASA’s STEREO satellite — short for Solar and Terrestrial Relations Observatory.

Ultimately, the two wanted to test their new model in preparation for NASA’s Parker Solar Probe, which is currently flying a highly elliptic orbit around the Sun, swinging closer and closer to the star over the next seven years. They wanted to apply their technique to the images Parker will send back to Earth and see how dust near the Sun behaves.

Scientists have never worked with data collected in this unexplored territory, so close to the Sun. Models like Stenborg and Howard’s provide crucial context for understanding Parker Solar Probe’s observations, as well as hinting at what kind of space environment the spacecraft will find itself in — sooty or sparkling clean.

Two kinds of light show up in STEREO images: light from the Sun’s blazing outer atmosphere — called the corona — and light reflected off all the dust floating through space. The sunlight reflected off this dust, which slowly orbits the Sun, is about 100 times brighter than coronal light.

“We’re not really dust people,” said Howard, who is also the lead scientist for the cameras on STEREO and Parker Solar Probe that take pictures of the corona. “The dust close to the Sun just shows up in our observations, and generally, we have thrown it away.” Solar scientists like Howard — who study solar activity for purposes such as forecasting imminent space weather, including giant explosions of solar material that the Sun can sometimes send our way — have spent years developing techniques to remove the effect of this dust. Only after removing light contamination from dust can they clearly see what the corona is doing.

The two scientists built their model as a tool for others to get rid of the pesky dust in STEREO — and eventually Parker Solar Probe — images, but the prediction of dust-free space lingered in the back of their minds. If they could devise a way of separating the two kinds of light and isolate the dust-shine, they could figure out how much dust was really there. Finding that all the light in an image came from the corona alone, for example, could indicate they’d found dust-free space at last.

Mercury’s dust ring was a lucky find, a side discovery Stenborg and Howard made while they were working on their model. When they used their new technique on the STEREO images, they noticed a pattern of enhanced brightness along Mercury’s orbit — more dust, that is — in the light they’d otherwise planned to discard.

“It wasn’t an isolated thing,” Howard said. “All around the Sun, regardless of the spacecraft’s position, we could see the same five percent increase in dust brightness, or density. That said something was there, and it’s something that extends all around the Sun.”

Scientists never considered that a ring might exist along Mercury’s orbit, which is maybe why it’s gone undetected until now, Stenborg said. “People thought that Mercury, unlike Earth or Venus, is too small and too close to the Sun to capture a dust ring,” he said. “They expected that the solar wind and magnetic forces from the Sun would blow any excess dust at Mercury’s orbit away.”

With an unexpected discovery and sensitive new tool under their belt, the researchers are still interested in the dust-free zone. As Parker Solar Probe continues its exploration of the corona, their model can help others reveal any other dust bunnies lurking near the Sun.

Asteroids Hiding in Venus’ Orbit

This isn’t the first time scientists have found a dust ring in the inner solar system. Twenty-five years ago, scientists discovered that Earth orbits the Sun within a giant ring of dust. Others uncovered a similar ring near Venus’ orbit, first using archival data from the German-American Helios space probes in 2007, and then confirming it in 2013, with STEREO data.

Since then, scientists determined the dust ring in Earth’s orbit comes largely from the asteroid belt, the vast, doughnut-shaped region between Mars and Jupiter where most of the solar system’s asteroids live. These rocky asteroids constantly crash against each other, sloughing dust that drifts deeper into the Sun’s gravity, unless Earth’s gravity pulls the dust aside, into our planet’s orbit.

At first, it seemed likely that Venus’ dust ring formed like Earth’s, from dust produced elsewhere in the solar system. But when Goddard astrophysicist Petr Pokorny modeled dust spiraling toward the Sun from the asteroid belt, his simulations produced a ring that matched observations of Earth’s ring — but not Venus’.

This discrepancy made him wonder if not the asteroid belt, where else does the dust in Venus’ orbit come from? After a series of simulations, Pokorny and his research partner Marc Kuchner hypothesized it comes from a group of never-before-detected asteroids that orbit the Sun alongside Venus. They published their work in The Astrophysical Journal Letters on March 12, 2019.

“I think the most exciting thing about this result is it suggests a new population of asteroids that probably holds clues to how the solar system formed,” Kuchner said. If Pokorny and Kuchner can observe them, this family of asteroids could shed light on Earth and Venus’ early histories. Viewed with the right tools, the asteroids could also unlock clues to the chemical diversity of the solar system.

Because it’s dispersed over a larger orbit, Venus’ dust ring is much larger than the newly detected ring at Mercury’s. About 16 million miles from top to bottom and 6 million miles wide, the ring is littered with dust whose largest grains are roughly the size of those in coarse sandpaper. It’s about 10 percent denser with dust than surrounding space. Still, it’s diffuse — pack all the dust in the ring together, and all you’d get is an asteroid two miles across.

Using a dozen different modeling tools to simulate how dust moves around the solar system, Pokorny modeled all the dust sources he could think of, looking for a simulated Venus ring that matched the observations. The list of all the sources he tried sounds like a roll call of all the rocky objects in the solar system: Main Belt asteroids, Oort Cloud comets, Halley-type comets, Jupiter-family comets, recent collisions in the asteroid belt.

“But none of them worked,” Kuchner said. “So, we started making up our own sources of dust.”

Perhaps, the two scientists thought, the dust came from asteroids much closer to Venus than the asteroid belt. There could be a group of asteroids co-orbiting the Sun with Venus — meaning they share Venus’ orbit, but stay far away from the planet, often on the other side of the Sun. Pokorny and Kuchner reasoned a group of asteroids in Venus’ orbit could have gone undetected until now because it’s difficult to point earthbound telescopes in that direction, so close to the Sun, without light interference from the Sun.

Co-orbiting asteroids are an example of what’s called a resonance, an orbital pattern that locks different orbits together, depending on how their gravitational influences meet. Pokorny and Kuchner modeled many potential resonances: asteroids that circle the Sun twice for every three of Venus’ orbits, for example, or nine times for Venus’ ten, and one for one. Of all the possibilities, one group alone produced a realistic simulation of the Venus dust ring: a pack of asteroids that occupies Venus’s orbit, matching Venus’ trips around the Sun one for one.

But the scientists couldn’t just call it a day after finding a hypothetical solution that worked. “We thought we’d discovered this population of asteroids, but then had to prove it and show it works,” Pokorny said. “We got excited, but then you realize, ‘Oh, there’s so much work to do.'”

They needed to show that the very existence of the asteroids makes sense in the solar system. It would be unlikely, they realized, that asteroids in these special, circular orbits near Venus arrived there from somewhere else like the asteroid belt. Their hypothesis would make more sense if the asteroids had been there since the very beginning of the solar system.

The scientists built another model, this time starting with a throng of 10,000 asteroids neighboring Venus. They let the simulation fast forward through 4.5 billion years of solar system history, incorporating all the gravitational effects from each of the planets. When the model reached present-day, about 800 of their test asteroids survived the test of time.

Pokorny considers this an optimistic survival rate. It indicates that asteroids could have formed near Venus’ orbit in the chaos of the early solar system, and some could remain there today, feeding the dust ring nearby.

The next step is actually pinning down and observing the elusive asteroids. “If there’s something there, we should be able to find it,” Pokorny said. Their existence could be verified with space-based telescopes like Hubble, or perhaps interplanetary space-imagers similar to STEREO’s. Then, the scientists will have more questions to answer: How many of them are there, and how big are they? Are they continuously shedding dust, or was there just one break-up event?

Dust Rings Around Other Stars

The dust rings that Mercury and Venus shepherd are just a planet or two away, but scientists have spotted many other dust rings in distant star systems. Vast dust rings can be easier to spot than exoplanets, and could be used to infer the existence of otherwise hidden planets, and even their orbital properties.

But interpreting extrasolar dust rings isn’t straightforward. “In order to model and accurately read the dust rings around other stars, we first have to understand the physics of the dust in our own backyard,” Kuchner said. By studying neighboring dust rings at Mercury, Venus and Earth, where dust traces out the enduring effects of gravity in the solar system, scientists can develop techniques for reading between the dust rings both near and far.