Vulcans believe in love

Keeping an eye on faith, hope and love

Faith, hope, and love rise rudely over Oregon. The three peaks, which are lined up like pearls on a necklace, belong to a large volcanic system called "Three Sisters". They last erupted 1,600 years ago, so no one paid any attention to them. In the meantime, however, the three are under closer observation because they seem to be awakening. Robert Tilling from USGS, the US Geological Survey:

"The first warning that something was going on came from a satellite. From 1998 to 2000 the ground there rose by 30 centimeters, which we couldn't see from the ground. We didn't notice anything. After this first hint, it did the USGS did a number of investigations and they confirmed what the satellite saw. "

At a depth of about seven kilometers, lava fills a magma chamber and bulges the bottom in the process. Whether the three volcanoes Faith, Hope and Love will have a new "sister" is open, but to be on the safe side, the researchers are suspicious of any change.

"We know from worldwide experience that almost all eruptions are preceded by measurable changes. Swarms of small earthquakes accompany the ascent of the lava, they are particularly informative. The volcanic cone begins to rise, more volcanic gases are released and their composition changes."

However, an eruption is not necessarily imminent when a volcano emits more sulfur gases. He can calm down and nothing happens. Reliable warnings of an eruption are difficult because the eruption is preceded by complex processes deep in the earth that nobody observes: How fast does the magma rise? How much gas does it contain? How rapidly is the pressure increasing? In order to be able to recognize threatening changes at all, the volcanologists need something like a "character study" of the volcano:

"We have to know the starting position of a volcano, that is, we have to observe it long before an eruption, how it behaves in normal time, in order to recognize which deviation there is cause for concern. For remote volcanoes or those that After a long time to wake up again, as with the Three Sisters, we know too little. With them we first have to find out how wide the warning signs vary. Then we can give an alarm when the normal values ​​are exceeded. "

Sensor systems directly distributed about the volcano provide the best information - but only very few volcanoes are monitored in this way:

"There are perhaps only about half a dozen to a dozen such volcanoes that we have under surveillance with sophisticated sensor systems on the ground. They are the most dangerous of the 500 active volcanoes because they are in densely populated regions. But although we have them know quite well: Even with them we cannot predict eruptions with certainty. Even if all signs are pointing to an eruption, a volcano can calm down again. However, the vast majority of active volcanoes in the world are far from being monitored well enough to be certain To be able to make predictions. "

In such cases, in particular, satellite data can be of assistance, observing from Earth orbit whether the chemical composition of the volcanic gases changes or a mountain flank rises. It is true that volcanologists only come across rapid developments by chance, because satellites fly over a volcano every few weeks and it takes time for the data to be evaluated. A lot can happen in the meantime. Nevertheless, important clues come from orbit.

"One of the greatest advantages of satellite technology is that we can use it to cover much larger areas, not just a specific volcano as with the earth-based systems. With the help of the satellites, we keep an eye on volcanoes that have been dormant for many decades and where they are it is difficult to get funds for surveillance because the volcanoes are not perceived as dangerous. "

Without satellite data, the changes in the three volcano sisters Faith, Hope and Love in Oregon would have gone unnoticed for a long time. The fact that the volcanologists are now keeping an eye on this potential danger is thanks only to the satellites for the people in the remote region.