Volcanic Ash Advisory Centre in Montreal

Volcanic ash can present a significant hazard to aviation, particularly to aircraft that are in flight when it is present in the air. Flying through an ash cloud can result in damage to engines, airframe and electronics, potentially leading to partial or total loss of flight control and communication.

This is why the International Civil Aviation Organization has created Volcanic Ash Advisory Centres (VAACs) throughout the world, and one of those is run out of Montreal, Quebec by Environment Canada. This centre is responsible for the continuous monitoring of volcanic activity, and for issuing statements that warn users of the presence of volcanic ash and give its expected movement in the next several hours.

The VAAC Montreal is one of nine centres worldwide.  The other VAAC locations are:

• Washington DC, US
• Anchorage (Alaska), US
• Tokyo, Japan
• Darwin, Australia
• Wellington, New Zealand
• Buenos Aires, Argentina
• Toulouse, France
• London, United Kingdom

Its area of responsibility can be seen on this map. In addition to its responsibilities, VAAC Montreal provides operational support and backup to the other VAACs worldwide.

Within Canadian-controlled airspace, the primary volcanic eruption hazard exists along the area in the Pacific Ocean known as the "Ring of Fire."  This is a horseshoe-shaped area along the edges of the Pacific Ocean where large numbers of earthquakes and volcanic eruptions occur. The VAAC Montreal also monitors volcanic activity along and east of an underwater mountain range in the Atlantic Ocean known as the Mid-Atlantic Ridge, including Iceland.

So how does it work? Well, the VAAC Montreal is alerted in real-time to reports of volcanic eruption or aircraft that encounter ash. These alerts come from many international sources. However, the centre ultimately receives direct notification of a potential ash problem from three primary sources: 

• The Alaska Volcano Observatory of the US Geological Survey
• The Cascade Volcano Observatory of the US Geological Survey
• The Pacific Geoscience Center of the Geological Survey of Canada

Imagery from satellites is the main way that data is gathered for detecting the boundaries of a volcanic ash cloud (a cloud that is made up partly or entirely of volcanic ash), and for estimating the current altitude and movement of concentrated areas of ash known as “plumes.” Satellite imagery is then used in combination with computer models and other observational data to forecast the progression of a volcanic ash cloud (progression meaning where it is, how much it is growing and where it is headed). This then allows the VAAC to alert the aviation industry and warn them of the potential danger to flying in a certain area of the sky.

Volcanic ash advisory statements

When airborne volcanic ash is observed or forecast to be present in a VAAC's area of responsibility, the VAAC will issue a Volcanic Ash Advisory Statement. 

These advisories are intended to provide the following information, mainly to the airline industry, in a timely manner:

• geographic information (location, name, elevation) of the eruption source
• a summary of recent observations, including their type and time
• details of observed ash plume location, dimensions, and recent motion
• general discussion of the expected path of the ash plume
• reference to current aviation warnings known as SIGMETs (SIGnificant METeorological aviation hazard)

In addition, the VAAC Montreal routinely generates forecasts of concentrations of ash and the expected paths the ash will take through the atmosphere. These forecasts, which are shown on maps are available in real-time, on a global scale. The advisories are issued in response to volcanic eruptions or other environmental emergencies.