The most difficult natural dis­as­ters riddles

The whole process begins when hot magma is lifted by convection to the magma chamber. As the pressure in the chamber is lower than deep in Earth's crust, the gas starts to release. Since degassed magma has lower density, it may then sink and be replaced with new one. This process may build up huge pressure of gases, eventually causing explosion.

On April 13, 2029, Apophis will pass Earth within the orbits of geosynchronous communication satellites, but will come no closer than 19,400 miles (31,200 km) above Earth's surface.[12] The 2029 pass will be much closer than had first been predicted. The pass in late March 2036 will be no closer than about 23 million kilometres (14×106 mi)—and will most likely miss Earth by something closer to 56 million kilometres

Tornado Alley is a colloquial term for the area of the United States where tornadoes are most frequent. The term was first used in 1952 as the title of a research project to study severe weather in areas of Texas, Oklahoma, Kansas, South Dakota, Iowa, Illinois, Missouri, Nebraska, Colorado, North Dakota, and Minnesota.

There are no active volcanoes on the Australian mainland that have erupted since European settlement, however, some volcanoes in Victoria and South Australia are likely to have been active and witnessed by Aboriginal people several thousand years ago.

Lying mostly underwater, Campi Flegrei comprises 24 craters. It is one of the largest volcanoes in the world, capable of producing VEI 7 (super-colossal) eruptions. Its most recent eruption of 1538 created a new hill, Monte Nuovo.

At 21:22, on the evening of March 4, 1977, Bucharest was hit by an earthquake measuring a whopping 7.3 on the Richter scale. The city center suffered significant damage and many historic buildings were destroyed. The earthquake killed about 1,578 people in Romania (1,424 in Bucharest), and wounded more than 11,300.