VENEZUELA: Lightning in the Sky Fed by Underground Methane
CONGO MIRADOR, Venezuela -- A red, yellow and orange flash illuminates a slice of the sky and Lake Maracaibo in Venezuela. For a fraction of a second after, lightning of incandescent white move left to right and right to left between small clouds like dark silhouettes.
By Humberto Márquez*, IPS/IFEJ
Seconds later the phenomenon repeats, with different tones and intensity and new shapes of neighbouring clouds, lasting for hours, with a distant and muted rumour of thunder, until the charged convective clouds cease their pyrotechnic game and turn into a regular storm. It rains -- a deluge that lasts six hours.
The lightning of the Catatumbo -- over the delta of the river of the same name, which begins in north-eastern Colombia and flows among marshes and lagoons into Lake Maracaibo, in western Venezuela -- is a cloud-to-cloud electrical storm, linked to a permanent low pressure in the area, rich in methane that is set alight and glows.
"This is the place in the world with highest average time with electrical storms per year," says Venezuelan environmentalist Eric Quiroga, promoter of Sep. 16 as International Day for Preservation of the Ozone Layer.
The Catatumbo has lightning 140 to 160 nights per year, lasting about seven hours, in two cycles just before and after midnight, for about 980 hours annually, with an average of 28 strikes per minute, for a grand total of 1,646,000 per year, according to Quiroga.
The sites with greatest occurrence of electrical storms in the world are El Bagre, in Antioquia, Colombia (270 days per year); Tororo, Uganda (251 days), and Bogor, in Java, Indonesia (223 days). In Tororo and El Bagre, the lightning lasts about two hours, usually occurs during the day, and between clouds and land.
The cloud-land electrical charges have an intensity of 10,000 to 50,000 amperes, while cloud-cloud charges are between 100,000 and 300,000 amperes. "Each bolt could light all the bulbs of South America. An average of 1.6 million strikes per year and an average intensity of 150,000 amperes make the Catatumbo the leading source in its type of electrical generator on the planet," Quiroga said in an interview for this report.
It is the glow that one sees as night falls, watching from the fishing boats, from Puerto Concha to Ologá and Congo Mirador, villages built on stilts on the south side of the lake, which at moments becomes a mirror of light.
Where does the methane come from that feeds the flashes? For years, the predominant thesis was that it emanated from decomposing organic material nourished by the torrential rains in the southern lake watershed, some 600 km southwest of Caracas, where winds from the northeast and southwest collide.
But researcher Angel Muñoz, of the regional University of Zulia, suggests that there is kerogen (a mixture of organic compounds found in sedimentary rocks) in the subsoil of the lagoons of dark waters between the neighbouring Bravo and Catatumbo rivers.
"The substrata of the lake are rich in petroleum deposits and share with the river marshes the same geological history. The accumulation of methane in the atmosphere could be favored by leaks of this gas through fissures in the rocky mantle and into the marshes and lagoons," says Muñoz.
That would explain the mysterious disappearance of the lightning or the increase in its frequency and intensity after earthquakes in the area.
The lightning "appears above La Estrella lagoon and its dark waters, a little to the west of here. That is where I have best seen it on summer nights with clear skies," says the oldest resident of Congo Mirador, José del Carmen Guerrero, a 79-year-old fisherman and community activist.
His wife, María Díaz, 65, recalls that "when I was young, the lightning was bigger and stronger. In my opinion it has diminished."
Quiroga says that "perhaps the methane emissions have varied," and the intensity over the lagoons is explained because "those waters absorb more energy, and the south of the lake is one of the sites with most solar radiation in the world: by day, the light dissolves the methane, but at night, on currents of warm air, it rises quickly to the high clouds."
While water vapor goes to the lower clouds to create rain, the methane ascends up to seven or eight kilometres in the sky, and when the ice particles in the enormous convective clouds are ionized it produces electrical discharges sometimes seen as far away as 400 km, from the islands of the southern Caribbean.
"I am very proud. The lightning produces ozone, and the ozone protects life on all the planet," says fisherman Alexis Vega, 49, standing on the narrow strip of sand between Lake Maracaibo and Ologá lagoon, after listing the things the town lacks. Half of the houses, made of metal sheeting, are on the coast, half are built on stilts.
Quiroga picks up again on the explanations: "At more than six kilometres high, the lightning is a generating source of ozone. It could be that the Catatumbo is the leading source of its type in the world," although the electrical storms produce just 10 percent of the ozone in the stratosphere that protects Earth from the Sun´s harmful rays.
The lightning is also shown proudly on the shield and the flag of the oil-rich state of Zulia, in spite of the misery of the "water villages", some 800 residents in Congo Mirador, 200 in Ologá, and dozens more spread in other settlements.
The inhabitants present a list of complaints because there are shortages of electricity, potable water, fuel, food, medical care, education and other services and opportunities. Some see it as governmental disdain.
In late October and early November, about 20 young artists, participants in a course of the Caracas Museum of Contemporary Art, faced the inclement weather seeking compensation with the orange, yellow and white light show.
Meanwhile, the Wayúu Indians, who watch the lightning from the north side of the 12,000-square-km lake, see in it the spirits of their dead loved ones, whose souls glow in the clouds.
For the indigenous Barí, on the southwest side of the lake, and whose language gave rise to the names Catatumbo and Zulia, the lightning is a concentration of millions of fireflies who gather at night to pay tribute to the creators.
(*This story is part of a series of features on sustainable development by IPS-Inter Press Service and IFEJ-International Federation of Environmental Journalists.)
Published by: Magne Ove Varsi