“Vog”的意思、由来-开放百科全书

Vog is created when volcanic gases (primarily oxides of sulfur) react with sunlight, oxygen and moisture. The result includes sulfuric acid and other sulfates.^[2] Vog is made up of a mixture of gases and aerosols which makes it hard to study and potentially more dangerous than either on their own.^[3]

Vog, which originates from volcanic vents, differs from laze, created when lava enters the ocean.^[3]

Vog in Hawai{{okina}}i

In Hawaii, the gas plumes of Kīlauea rise up from three locations: Halema{{okina}}uma{{okina}}u Crater, Puʻu ʻŌʻō vent, and from along the coastline where lava flows from the East Rift zone enter the ocean. The plumes create a blanket of vog that can envelop the island. Vog mostly affects the Kona coast on the west side of the Island of Hawai{{okina}}i, where the prevailing trade winds blow the vog to the southwest and southern winds then blow it north up the Kohala coast.

Prolonged periods of southerly Kona winds, however, can cause vog to affect the eastern side of the Island on rare occasions, and affect islands across the entire state as well.^[4] By the time the vog reaches other islands, the sulfur dioxide has largely dissipated, leaving behind ash, smoke, sulfates, and ammonia.^[5]

Comparing vog and smog

Vog and smog are different. Vog is formed when sulfur oxides emitted by a volcano react with moisture to form an aerosol. The aerosol scatters light, thus making the vog visible. Smog is formed largely from the incomplete combustion of fuel, reacting with nitrogen oxides and ozone produced from carbon monoxide by reactions with sunlight. The result is also a visible aerosol.

When smog levels are high, the sky appears yellowish-grey because nitrogen oxides are yellow. In contrast, sulfur oxides are colorless and vog looks grey. Once the vog layer dissipates, grey spots of vog in the sky may, for a time, remain trapped in the inversion layer.

Several chemicals emitted from cars are not emitted from volcanoes. Similarly, some chemicals emitted from volcanoes, such as hydrogen sulfide, hydrogen chloride, and hydrogen fluoride, are not created by traffic pollution. Moreover, smog generated by factories has its own unique mix of contaminants.

Health hazards

Most studies of vog have been in areas where vog is naturally present and not in controlled conditions. Vog contains chemicals that can damage the environment and the health of plants, humans and other animals. Most of the aerosols are acidic and of a size where they can remain in the lungs to damage the lungs and impair function. Headaches, watery eyes, sore throat, breathing difficulties (including inducing asthma attacks), flu-like symptoms and general lethargy are commonly reported. These effects are especially pronounced in children and in people with respiratory conditions. Vog generally reduces visibility, creating a hazard for road, air and ocean traffic.^[1]

Recent events

Several studies are underway to measure the air quality near volcanoes more carefully.^[6]

Sulfur dioxide emissions increased on March 12, 2008, when a new vent opened. The increased vog level has caused evacuations and damaged crops. In the summer of 2008 and in 2012, the County of Hawai{{okina}}i received a disaster designation due to the agricultural damage.^[7]

A recent multi-year computer-modeling feasibility study, known as VMAP, designed to predict the location and concentrations of vog from Kīlauea was conducted by the University of Hawaii.^[8]

See also

References

1. ^¹{{cite web|url= http://hvo.wr.usgs.gov/hazards/FAQ_SO2-Vog-Ash/P1.html |title=Frequently Asked Questions about Air Quality in Hawaiʻi |work= on USGS web site |publisher= U.S. Geological Service|accessdate= 2009-12-29 }}
2. ^"Sulfur Dioxide" on US Environmental Protection Agency web site
3. ^HOW VOG IS MADE: A PHOTOGRAPHIC PERSPECTIVE, Vog and Laze Seminar (July 29, 1991)
4. ^¹"Vog: A Volcanic Hazard" on USGS web site
5. ^{{Cite web |url=http://www.mauiweekly.com/page/content.detail/id/9344/Vog-Taints-Maui-Skies.html |title=Vog Taints Maui Skies |access-date=2009-12-29 |archive-url=https://web.archive.org/web/20110321000537/http://www.mauiweekly.com/page/content.detail/id/9344/Vog-Taints-Maui-Skies.html |archive-date=2011-03-21 |dead-url=yes |df= }}
6. ^Hawaii Air Quality Conditions & Forecasts on "Airnow" US Government web site
7. ^"Vog: Important Information and Facts" on State of Hawaii Office of the Governor web site
8. ^{{cite journal | url=http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-14-00150.1 | title=Observing and Forecasting Vog Dispersion from Kīlauea Volcano, Hawaii | author=Businger, S., Huff, R., Pattantyus, A., Horton, K., Sutton, A. J., Elias, T. and Cherubini, T. | journal=Bulletin of the American Meteorological Society | year=2015 | volume=96 | pages=1667–1686 | doi=10.1175/BAMS-D-14-00150.1| bibcode=2015BAMS...96.1667B }}