spiegazione incendi los angeles cause

Fires in Los Angeles, all the possible causes: electrical failures, drought, Santa Ana winds

They have been going on for 6 days now fires in Los Angeles in California that began last Tuesday: the number of victims is at least 24 peopleat least 180,000 evacuated and were burned – which was distributed in 5 serious fires163km2 of land, an area slightly larger than the city of Palermo. The two main fires, Palisades and Eaton they reached an extension of 9600 hectares and 5700 hectares respectively, with containment percentages of 13% and 27% respectively. The map of fires also currently shows Hurst (323 hectares), 89% tamed.

What caused the fires in Los Angeles? The electricity grid hypothesis

A hypothesis that is gaining ground regarding the triggering cause of the fires in Los Angeles is that of malfunctions in the electricity grid of the metropolis. Second Bob MarshallCEO of Whisker Lab (a company that monitors energy supplies), the sensors available to the company would have identified an unusually high number of faults and stress on the lines in the vicinity of the places where the fires started, moreover just a few hours after their beginnings, particularly for the Hurst fire. Of course this it’s just a hypothesis which will have to be verified or denied by investigations.

Santa Ana winds, drought and water shortages

As for the conditions that made the fires so extensive and difficult to put out deserve further investigation Santa Ana winds which are expiring these days in Southern California. These are twenty intense, hot and dry typical of these areas, which form in the desert hinterland of the western United States and blow towards the coast, accelerating and heating when they descend from the mountains surrounding Los Angeles: a behavior not too different from that of the winds of favonius (foehn) on our Alps. They can be seen perfectly in satellite images, which show the winds pushing the smoke from the fires into the ocean:

These are winds that often blow in autumn-winter, when anticyclonic structures impose themselves over the Mojave or Nevada desert.

These winds are a very important ingredient in the formation of fires in Southern California, for several reasons:

  • being warm and dried they remove humidity from the vegetation, which therefore becomes more likely to catch fire;
  • being fast they transport the flames effectively.

These days the Santa Ana winds are blowing with peaks of even 120 km/h and a humidity around the 10% during the day. That’s exactly what Not we want in the presence of forest fires. If to this we then add a extremely dry soil after six months with practically no rain And scarcity of water in reservoirs due to the drought itself, the perfect recipe for large fires is created even though we are in the middle of winter.