Radio Vulcano trasmette la voce dei fulmini eruttivi

Spaceweather.com parla di una missione scientifica che in Islanda sta studiando un fenomeno poco conosciuto (e dalle cause ancora misteriose) associato alle eruzioni vulcaniche: nelle nuvole incandescenti di lava, ceneri e gas si accendono le scariche di veri e propri fulmini. Considerando la difficoltà di osservare questi lampi in normali condizioni di ripresa, gli scienziati del politecnico New Mexico Tech stanno costruendo intorno all'Eyjafjallajokull (nessuna relazione con il Faiallo) una rete di sensori RF che "ascoltano" le scariche ricostruendone la mappa tridimensionale.

It is well known that volcanic eruptions produce strong lightning. Less well known is why? Ordinary lightning in thunderstorms is not fully understood; volcanic lightning is even more of a mystery.To investigate, a team of researchers from New Mexico Tech has traveled to Iceland to monitor the Eyjafjallajokull volcano--and they have found it crackling with electricity. Photography is one way to monitor volcanic lightning, but the technique has limits: Ash clouds are able to hide the flashes; lightning is not always visible in daylight; glowing lava competes for attention; and so on. Radio receivers can do a better job. Lightning emits impulsive radio bursts which can be measured and counted, day or night, even through clouds of ash. "We are deploying a six-station lightning mapping array around the Eyjafjallajokull volcano," says Harald Edens. Their analysis of the radio "crackles" could reveal much about the inner workings of volcanic lightning.