Volcanic Lightning
`Great Surtur with his flaming sword,
Southward at Muspel`s gate kept ward.
And flashes of celestial flame
Life giving from the fire world came`
Valhalla, J.G.Jones
The old Norse creation story tells of a world of ice fed from a spring and separated from a world of fire by a chasm illuminated by sparks from the sword of the giant Surtur.
My birthday present in 1963 emerged from the sea at 6.30 am on the morning of November 14th. Clouds of ash and sparks, lava boiling the sea and dense clouds of steam; all illuminated by flashes of lightning , a new island off Iceland which was named for the legendary fire giant - Surtsey! Surtsey was to initiate studies into volcanic lightning via sea water charging, but, as Kipling used to say `That is another story`, reserved for later chapters.
Herbert of Clervaux (1178) in his Liber Miraculorum (Book of Miracles) tells of islands bursting from the depths of the sea. Even earlier St. Brendan sought to comfort his terrified sailor monks in their oxhide boat off Iceland as bombs of lava fell from the ash darkened skies,"Soldiers of Christ, be strong in Faith unfeigned and in the armour of the Spirit, for we are now on the confines of Hell."
`There were thunders and lightnings and a thick cloud upon the mountain.... A pillar of cloud by day and a column of fire by night.` Book of Exodus.
The innocent tree rings and silent, dark core samples of seabed from near Santorini confirm a terrible volcanic explosion of the volcano Thera in 1628 B.C. One thousand billion cubic feet of rock ended Minoan Crete under 22 feet of ash and affected oaks in Ireland, damaged Arizona Bristlecone Pine trees with frost as the world climate was changed. A Hebrew prophet called again on the ruler of Eygpt, "Let my people go". This time he agreed and the exodus began into the wilderness of Sinai guided by the pillar of cloud and fire from the Thera explosion. Plato would write of a civilisation which in a night and day sank into the depths of the sea leaving men to ponder on the mystery of Atlantis.
The volcanic lightning of this event lived on into the writings of such as Hesiod in his Theogany (c735BC) `The heat of thunder and lightning and of fire from such a monster, the heat of the fiery storm winds and flaming thunderbolt. And the whole earth and sea boiled.` And in Pindar`s Paean (c460BC) `The heavy sounding war between Zeus and Poseidon with thunderbolt and trident.`
Lucretius wrote of `The fire of Etna to overflow, the heaven to be in flames; for that too is seen and the heavenly quarters are on fire` - volcanic lightning?
At about one in the afternoon of August 24th 79A.D., there was a `most intense darkness rendered more appalling by the fitful gleam of torches at intervals obscured by the transient blaze of lightning`(Pliny). Vesuvius was in eruption. Pompeii and Herculaneum were about to be destroyed and the dormant ash would, two thousand years later pour as mud into Italian towns near the volcano.
Again it erupted in 1707 with lightning issuing from the mouth of the crater and described as `resembling that seen in tempests but assuming a more twisted and serpentine form.`
Brave Palmieri made the first attempt to investigate electrical charge in the steam clouds, in the eruption of Vesuvius in 1872. He detected positive charge in steam clouds, negative in ash clouds and both polarities in mixed clouds.
On April 6th 1906 a new, possibly electrical, phenomenon appeared among `St.Elmo`s fire and lightning`. A `yellowish ionised light which flashed at `lightning speed from the crater at the height of the eruption` was named the Flashing Arc`.
The Italian people call the ejectamenta cloud issuing from Vesuvius, The Pine. `In the column, but more frequently in the cloud above it, flashes of forked lightning are seen every moment in all directions and are accompanied by thunder`.
Official U.S. Air Force Photo
Vesuvius in Eruption March 1944
Molten lava on the sides beneath the glow from the crater and spectacular volcanic lightning in the cloud.
Wing Commander Shore flew through the twenty thousand foot high cloud on March 27th and reported that lightning forked at a height of eight thousand feet.
Captain Woolridge commanding the Sir Robert Sale entered in the ships log at 4a.m., on August 26th 1883, ` The cloud has the appearance of an enormous pine tree the stem and branches formed with violent lightning. An immense wall with bursts of forked lightning at times like large serpents rushing through the air.` The Sir Robert Sale was standing off the island off Krakatoa in the Straits of Sunda. A ship lying forty five miles off was struck five times on the mainmast conductor.
The Royal Society expedition reported `A terrible storm of a strictly local character, which raged during the whole time of the eruption. The electrical disturbances, resulting in vivid lightning, fireballs, corposants.(Corona glows).
zigzagzigzagzigzagzigzagzigzagzigzagzigzagzigzagzigzagzigzagzigzagzigzag
Other instances
When Katla in Iceland erupted from beneath its glacial ice in 1755,` Zig-zag lightning from the steam cloud killed eleven horses and two men and pierced cylindical holes in some rocks in the way of the group`.
At 7.50 a.m., May 8th 1902 the side of Mount Pelee opened and a horizontal black cloud emitting noises like gunfire, from continuous lightning, reached the town of St.Pierre, five miles away, within seconds and thirty thousand people perished (one survived - a convict in an underground cell).
The lightning in the cloud above Paracutin, the volcano which came up in a Mexican cornfield, occurred at intervals of about one to five minutes.
Captain Tillard sailing North West of San Miguel on June 13th 1811 saw a column of smoke rising from the sea. Flashes of lightning in this cloud were followed by thunder which sounded like,`the continual firing of guns and muskets`. By July an island had emerged from the sea to a height of three hundred feet and a mile in circumference. Sea water poured into a large crack through the island, `from which water in a high state of ebullition(boiling) was continually and rapidly flowing`.
Ing. F. Penalba
The Eruption of Cerro Negro in Nicaragua 1971
This violent eruption of Cerro Negro in which electrical phenomena was recorded, `inside the cloud, between the cloud and the crater or main cone of the volcano` and the lightning photographed in a time exposure - the trails to the left are those of stars.
Ice and Fire
Thorarinsson searched Icelandic literature for accounts of volcanic lightning. Katla erupted in 1625 from beneath 500m of glacial ice and produced electrical corona described as `enveloping people and cattle in one continuous blaze or fire. On hats and garments there was seen so much glowing fire as if we were enveloped with flame or glowing coals. Yet it was not the colour as of our natural fire, but rather had the appearance of the shimmer on newly caught fish or that which some call corpse light or carrion flame. The said fire or flame swept or flew along the ground as well as through the air, so that all seemed aflame at the moment when it appeared`.
St. Elmo`s Fire streamed `like flames from weathercocks on farms and iron poles on churches - without the poles being warmed.`
Sigurgeir Jonasson
Lightning in Clouds over Surtsey
Surtsey may be said to have launched an intensive investigation of volcanic lightning mainly with respect to phreatic (water involved) eruptions.
Heimey in 1973 at one stage poured one hundred cubic metres of lava per second into the sea. Measurements were made of potential gradients of 7,000 volts per metre from positive steam clouds. Lightning photography proved poor due to the rain of tephra and snow and earth tremors, which shook the camera.
Comment
The above is distilled from my thesis, notes, reprints of the 1970s and, as I mentioned earlier, without references, measurements of charges or proposed charge sources.
What I have tried to convey is the magnetism of a little known natural phenomena which like all such draws us into its dreadful presence by its awesome power. Since the 1970s there have been many eruptions and lightning captured on film/videotape. Wider, faster communication along with vastly improved technology for recording natural phenomena has brought volcanic eruption into our homes via the television and videos.
Perhaps you may care to take up the subject which seems to have been set aside after 1978 when my thesis: -
Investigation of a Reproducible Boiling Phenomenon with Relevance to Volcanic Lightning
was presented to the Open University and papers from the investigation published in scientific journals.