Blogging the Vog

Earlier today I checked the traffic statistics for this blog, and I was pleased to see an upsurge in the number of visitors over the past few weeks. Then I noticed something disheartening about that increase in traffic. Most of the traffic was coming from search, and nearly all of the search terms had something to do with Kilauea volcano and its emissions. More specifically, judging from the search terms that brought readers here, people were looking for information about the vog (i.e., volcano smog) created by Kilauea's emissions, and its potential effects on their health.

Earlier this month I published an article here called Living with Hawaii's Active Volcano Can Leave You Breathless, in which I wrote about my own experience of health problems due to vog. Over the past few weeks, there have been more visits to that one article than to all of the rest of the articles on this blog combined. The runner up, by the way, was a related article I wrote in March, called Living with Hawaii's Active Volcano: Introduction.

Since there seems to be a lot of interest, I have decided to compile a list of resources about Kilauea and the vog, which I will publish soon here on the Virtual Scratchpad. If any readers have suggestions for what should be included on the forthcoming resource page, you are welcome to leave a comment to let me know.

Meanwhile, here is an update on the current vog situation on the Big Island:

This week we have been experiencing very light winds, a condition that has allowed the vog to settle over the island and accumulate, instead of blowing out to sea. On Wednesday, April 23, 2008, the Hawaii Volcanoes National Park was closed for the second time in less than a month because sulfur dioxide (SO2) levels had reached potentially dangerous levels. Some 2,000 visitors and staff were evacuated from the park. At this writing, the park remains closed, although local news reports said earlier today that the park may be reopened by this afternoon

There were no evacuations from residential areas, however the Hawaii County Civil Defense Agency issued several Emergency Health Advisories, broadcast on the radio and posted to the agency's website, warning residents in some communities of higher than normal levels of vog, and of SO2 in particular. For example, here is an excerpt from an advisory issued early this morning [Hawaii County Civil Defense Agency - Emergency Health Advisory #17, April 25, 2008, 06:00HST]:

• Volcano Golf and Country Club Estates remains on a Color Code RED status. Under Color Code RED those in sensitive groups should avoid outdoor activity and remain indoors, healthy individuals should avoid outdoor activity, and people experiencing respiratory related health effects should consider leaving the area.
• Volcano Village, Mauna Loa Estates, Ohia Estates, Royal Hawaiian Estates, Hawaiian Orchid Island Estates and Fern Forest subdivision are on Color Code Orange status. Under Color Code ORANGE potential health effects are not expected in healthy individuals, however, those in sensitive groups should avoid outdoor activity and remain indoors.
• The district of Ka’u and the communities of Upper Puna from Keaa’u to the 19 mile marker on Highway 11 are on Color Code YELLOW status. Under Color Code YELLOW those in sensitive groups should avoid outdoor activity.
• The district of lower Puna, from Keaau to Kalapana remains in Color Code GREEN. All other districts remain in Color Code GREEN.

I would like to note that the above health advisory refers to elevated levels of sulfur dioxide, which is only one component of vog (albeit potentially the most harmful). The advisory does not fully reflect overall vog conditions. While there is no advisory specified today for the Kohala Coast, where I live, vog definitely is present and heavier than usual.

Here at home, I have my own visual vog-level scale, based on what I can see -- and what I can't. I have a view to the ocean outside the window next to my desk. On no-vog days, I can see the ocean surface clearly, all the way to the horizon. On light vog days, I can still see the ocean, but the horizon is not well-defined. On heavy vog days like today, I cannot see the ocean; I can only see a whitish haze. While looking horizontally in any direction, structures and physical features more than about a quarter to a half mile away either are shadowy, or can't be seen at all.

On days like this, it is a small relief to know that the SO2 component of the vog is not high in my district, but that doesn't mean there is no vog: The reduced visibility outside tells the story. The National Weather Service forecasts light winds and "haze through the night" tonight, with winds becoming northerly at around 10 mph tomorrow afternoon. One can only hope that will be enough wind to blow the vog back out to sea.

About the Photo: A gas-and-ash plume emitted from Halemaumau crater at the Kilauea summit blows toward the southwest, driven by trade winds. This USGS photo was taken on April 18, 2008. To view more photos of Kilauea, visit the Kilauea Images page on the Hawaiian Volcano Observatory website.