Tag: explosions

The Eruption Of Kilauea Could Be So Terrifyingly Deadly

A “short-lived explosion” on May 9, 2018, caused by rocks falling into the lava lake. The lava lake is still above the water table at this point.

Hawaii’s Kilauea volcano has already shocked the world by sending massive walls of lava into houses and eating up cars, and spreading acid rain across the island. But that might just be the beginning.

Experts fear that the complex system underneath the volcano could be about to reach a new stage, which could see a blanket of ash and boulders the size of fridges thrown out of the volcano.

If those things are thrown out, they could easily kill the people below them. As such, people are being advised to stay out of closed areas of the national park that surrounds the volcano, where they should be safe.

If it goes up, it will come down,” said Charles Mandeville. “You don’t want to be underneath anything that weighs 10 tons when it’s coming out at 120 mph (193 kph).

The explosion will be so dramatic because of the structure of the volcano. Recent events have been changing the make-up of the volcano – and bringing about the explosive situation.




The lava lake in the volcano is in a rapid retreat – as shown in pictures released by the USGS this week. If it keeps going down, as it has done quickly, then it could trigger a run of events that would bring about ballistic effects.

In little more than a week, the top of the lava lake has gone from spilling over the crater to almost 970 feet (295 meters) below the surface as of Thursday morning, Mandeville said.

The lava levels in the lake are dropping because lava is spewing out of cracks elsewhere in the mountain, lowering the pressure that filled the lava lake.

The fear is that it will go below the underground water table — another 1,000 feet further down — and that would trigger a chain of events that could lead to a “very violent” steam explosion, Mandeville said.

At the current rate of change, that is about six or seven days away.

Once the lava drops, rocks that had been superheated could fall into the lava tube. And once the lava drops below the water table, water hits rocks that are as hot as almost 1,200-degrees Celsius and flashes into steam.

When the water hits the lava, it also steams. And the dropped rocks hold that steam in until it blows.

A similar 1924 explosion threw pulverized rock, ash and steam as high as 5.4 miles into the sky, for a couple of weeks.

If another blast happens, the danger zone could extend about 3 miles around the summit, land all inside the national park, Mandeville said.

Please like, share and tweet this article.

Pass it on: Popular Science

How Fireworks Work? Here Is The Chemistry Behind A Firework Explosion

fireworks

It’s Independence Day, and that means it’s time for controlled explosions in the sky. No, not Texas post-rock, the great scientific display that is a fireworks show.

“Fireworks are an application of chemistry and engineering: you need good chemistry to get the effects up in the sky and good engineering to make sure they get to the right altitude and burst at the right time,” John Conkling, the former director of the American Pyrotechnics Association.

Firework shows last between 15 to 20 minutes on average, but the amount of planning and preparation that goes into producing these displays can take up to two years.




Designers need ample time to determine the right colors and shapes they want to use, and to time the explosions to the soundtrack.

There are limits on the types of chemicals you can use, however. For one, they can’t be agents that collect moisture, or else they won’t burn properly when lit.

So from its initial lighting to its final spectacular explosion, a firework’s life begins with a lit gunpowder fuse, followed by a gunpowder-boost into the sky, and finishes with an explosion of a chemical medley of fuels, oxidizers, colorants, and binders.

As you enjoy these fiery tributes this weekend, remember how much science is involved behind the rockets’ red glare.

Please like, share and tweet this article.

Pass it on: Popular Science

The Collision: What Caused The Halifax Explosion?

The Imo came to rest against the Dartmouth shore on the other side of the harbor.

The Halifax Explosion was caused when two ships collided in the narrowest part of Halifax Harbor on the morning of Thursday, December 6, 1917.

The SS Mont Blanc, a French ship was arriving from New York City filled with munitions for World War I in Europe.

In addition to the 2,925 tons of explosives in its hold, it carried barrels of highly flammable benzol and picric acid on the deck.

Unable to travel with its scheduled convoy across the Atlantic, the Mont Blanc went to Halifax so it could travel with a new group.

It arrived the night before and had to wait outside the anti-submarine net that protected the harbor. At dawn, it began to move into the harbor.




Normally a munitions ship would fly a red flag to warn others of the dangerous cargo, but the Mont Blanc did not raise its warning flag.

Meanwhile, the SS Imo, a Norwegian ship carrying Belgian relief supplies that had been held up in the harbor for several days, began to move down the harbor toward the Atlantic.

The Imo’s captain was angry because he had been delayed and so he put to sea without the harbor master’s permission.

The two ships were maneuvering for position as they met in the Narrows between Halifax on the southern shore and Dartmouth on the northern shore.

Halifax harbor before the explosion.

Initially, the Imo refused to give way. Once it began to turn out of the Mont Blanc’s path, it could not move fast enough to avoid a collision.

Barrels on deck broke loose with the impact, and sparks from the scraping metal ignited the benzol that had spilled across the deck.

The Mont Blanc’s captain recognized the terrible danger of these fires and abandoned ship, rowing with the crew to the Dartmouth shore.

The damaged and burning Mont Blanc drifted to shore in the heavily populated wharf area of Halifax.

Halifax harbor after the explosion.

Crowds gathered on the shore and at windows to watch the burning ship run aground. Barrels of benzol began to shoot into the air like fireworks and explode. More people gathered to watch.

Approximately 20 minutes after the collision—at 9:04 a.m.—the fires ignited the 2,925 tons of munitions on the Mont Blanc and the ship exploded.

The ship was vaporized instantly, a huge area of Halifax was destroyed, and an enormous debris cloud rose over the city.

Please like, share and tweet this article.

Pass it on: Popular Science