Manizales, Colombia — Beneath a bank of windows looking out on the cloud-shrouded Nevado del Ruiz volcano, seismographs squiggle out a message that has scientists here increasingly concerned for thousands of Colombians living in the shadow of this Andean peak. The volcano, responsible for mud flows that killed more than 20,000 people in Armero last November, may be on the verge of another major eruption -- perhaps within days, say scientists here at the Volcanological Observatory of Colombia.
And it is not clear that the lesson of Armero has made this region much more prepared for a similar disaster.
In the few areas where alarms have been installed, tests last week showed that many were not working. Observers say Colombia has only a partial system of sirens in the area around the volcano. Many are battery-operated and prone to failure.
``It's inconceivable that after six months there is no effective alarm system here,'' says Joe Jack Hartmann, mayor of Mariquita, a town just 12 miles from Armero. Mr. Hartmann gave up waiting for a government alarm network to be installed and rigged a siren outside his office with wires running through a window to a switch on his desk. In the event of an eruption, he would have 40 minutes before the mud flows hit town to sound the alarm and call 19 other siren owners to sound warnings throughout the town.
Where test evacuations have been attempted on a large scale, they have been confused at best. And, even if lives can be saved in the event of a major eruption, there is apparently little preparation for providing food and shelter for survivors.
Scientists here admit their forecasts can be inexact regarding timing and magnitude of an eruption. Forecasts can vary by as much as several weeks, says Hans-J"urgen Meyer, a University of Valle seismologist on loan to the observatory. Predicting an eruption depends largely on knowing the idiosyncrasies of an individual volcano, he says. But that backlog of information doesn't exist for Nevado del Ruiz, since most seismologists had never even heard of the mountain before last October. Seismographs were installed here only last July.
The consensus among scientists observing the volcano here and abroad is that, if the forecast is right, not enough has been done to protect Colombians living downstream from the mountain from a disaster similar to the one in November. That eruption melted 5 percent of the volcano's icecap and sent waves of hot mud flowing down mountain rivers, killing people on at least two sides of the mountain.
Today in Mariquita, citizens in the line of a potential mud flow are uncertain about the situation.
Whipsawed between memories of Armero, the alarming scientific forecasts, and the government's low-key approach to the situation, the people don't know what to do. Many hike to high ground to sleep at night. Others, such as a city hall secretary, say they don't believe the scientific forecasts, because they aren't exact.
Observatory scientists began warning government and emergency agencies two weeks ago of a steady increase in harmonic tremors -- a continuous seismic disturbance indicating fluid movement underground and considered the most certain precursor of an eruption.
One scientist familiar with the situation says the Colombian government has ``a tendency to play down the situation, and whatever they are doing is too slow and doesn't reach the general population.''
``It's very rare that a volcano levels out at a high rate of activity like this for two weeks . . . a government normally doesn't have this kind of time for delay,'' says Jim Zollweg, a seismologist with the United States Geological Survey assigned to the observatory.
Dr. Zollweg put his assessment of the situation on record last week in a US Embassy bulletin: ``. . . harmonic tremor and earthquake levels observed at Nevado del Ruiz in the month of May 1986 indicate that a new eruption will be forthcoming in the immediate or near future, probably in a matter of a few days to several weeks . . . I believe that an explosive eruption, possibly of significant volume, is to be expected . . .
``Since an explosive eruption may generate pyroclastic flows over the glaciers, I urge that prompt and vigorous attention be paid to the possibility of renewed mud flows similar in magnitude of those of 13 November 1985.''
Putting this on record may have pressured the Colombian government to heed what is essentially the same warning the observatory issued two weeks ago. That warning, which was not acted upon, recommended the government prepare for evacuation. After Zollweg's report, the government called for a voluntary evacuation of residents living high on the mountain.
``The truth is that the risk [of a disaster worse than November's] exists, and that it is necesary to learn to coexist with it, and that it could produce at one moment or another a catastrophe,'' says Victor Ricardo, a presidential adviser who coordinates the National Disaster Committee. (After starting an interview, he informed the Monitor he would respond only to written questions on the subject.)
There are difficulties on all sides, says one US Embassy official. The government is criticized for taking a ``political'' position regarding the safety of Colombians, he says. ``Yes, it's political. When you make a decision to evacuate, you'd better be aware you're disrupting people and paralyzing an area for a time . . . they want to be sure it's really worth it.''
There have been three smaller eruptions since last year in addition to the November disaster. On Jan. 4, a scientifically forecast eruption led to the evacuation of 40,000 people. But all that occurred was a small eruption of ash.
This, says the embassy official, is an example that ``too many false warnings . . . is like crying wolf.''
``Nobody can rationally say that in Colombia we are ready, because we just don't know the magnitude that the tragedy could be. We've improved considerably in controls and alarms, although surely many things are left to be done,'' says Joach'in Caicedo, financial director of Resurgir (Spanish for ``to rise again''), a new government agency formed to administer volcano programs.
The advantage the average Colombian in this region has is the knowledge that an Armero-type disaster can occur. This alone keeps many citizens watchful, says Mariquita mayor Hartmann.