2023-05-23 19:01:02
Incandescent materials, ash and smoke are expelled by the Popocatépetl volcano.
In Mexico, a huge ash fall from the Popocatépetl volcano is causing great concern. More than 25 million people would be threatened by an eruption.
The volcano popocatepetl It currently lives up to its name in Nahuatl: “the hill that smokes”. In recent days it has repeatedly emitted ash, steam and gas. Located in the center of Mexico, between Mexico City and Puebla, Popocatépetl is considered one of the most dangerous volcanoes in the world, since an estimated 25 million people live within a radius of 100 kilometers around it. The civil protection agency of Mexico declared on Sunday (21.05.2023) a “yellow phase three” alert.
The Mexican early warning system for volcanic activity basically works like a traffic light, with the colors green, yellow and red, Hugo Delgado, a researcher at the UNAM Institute of Geophysics, explained in an interview with DW, before the alert level was raised. current.
The yellow level consists of three phases. In the second, the current one, they begin, for example, the maintenance activities of temporary shelters, as well as the revision of emergency exits and evacuation routes. In the third yellow phase, civil protection personnel are enlisted with the support of the Army, and the population begins to be prepared for a possible evacuation. In addition, food, blankets and beds are provided to the different shelters. At the red level, evacuations would begin.
Is there immediate danger?
After a long period of inactivity, Popocatépetl has been active again since 1994, and since then it has shown phases of increased activity, explains Thomas Walter, geologist and volcanologist at GeoForschungszentrum Potsdam. But in his opinion, the greatest danger to the population does not come from Popocatépetl, but from the monogenetic volcanic field on which the capital, Mexico City, sits. A monogenetic field typically contains between ten and one hundred volcanoes. “That does not mean that tomorrow there will be a volcanic eruption. We do not know. The problem with this monogenetic field is that it is not known where and when it will erupt,” says the volcanologist.
Thomas Walter has traveled to Mexico several times and has participated in research projects on various Mexican volcanoes, including the second largest in Mexico, Popocatépetl, 5,452 meters high.
Increased activity since the 1990s
On December 21, 1994, Popocatépetl produced its first ash emissions in 70 years, after a year of increasing seismic activity and sulfur dioxide emissions. Several towns (about 50,000 inhabitants) on the northeast flank of the volcano were evacuated immediately, but most of the inhabitants were able to return after a week. Episodic ash eruptions continued at low altitudes until 1995. In March 1996, a new round of activity began, with increased ash emissions and the growth of a lava dome in the summit crater. On April 30, 1996, an eruption killed five climbers who had ignored warnings to stay off the mountain.
under satellite observation
The current increase in activity at Popocatépetl is not entirely surprising, according to German researcher Thomas Walter: “It is one of the most permanently active volcanoes we know of and is therefore closely monitored.” This detailed observation includes not only the usual cameras and seismographs, but also two German Earth observation satellites: TerraSAR-X and TanDEM-X.
“We were able to see the crater from above with these satellites and realized that the floor had been rising and falling regularly for about two to three years,” says Walter. Seen in profile, the volcano would always look the same, but seen from above you could clearly see the many nested craters and their movement.
What can be observed especially well in Mexico at this time, says the volcanologist, are the so-called “volcanic bombs.” These are particles of more than 64 mm in diameter that are ejected by the volcano. Especially at night, these incandescent projectiles constitute an impressive natural spectacle. However, due to their relatively high weight, these particles fall to the ground in the immediate vicinity of Popocatépetl and, therefore, cause relatively little damage.
“These processes already show that Popocatépetl is significantly more explosive at this time, and that we have to be very vigilant. You shouldn’t downplay the activity, but you shouldn’t sow panic either,” says the Potsdam volcanologist.
(cp)
#Mexico #dangerous #Popocatépetl #volcano