Yorkshire volcanic ash helps to improve flight safety forecasts

Dr Graeme Swindles on a fieldwork trip at Malham Tarn Moss, Yorkshire Dales, where microscopic ash layers from prehistoric eruptions in Iceland were found. Credit: Paul J. Morris

Predictions of where planes can safely fly following volcanic eruptions could be improved, thanks to fresh discoveries about ash clouds.

To study the size of ash grains and how far they can travel, scientists at the Met Office and the Universities of Leeds, Edinburgh and Iceland, compared grains recovered from recent Icelandic eruptions – including samples recovered in Yorkshire – with satellite measurements of ash clouds.

Their findings, published today in Atmospheric Measurement Techniques, will help to improve methods of mapping ash concentration in order to identify zones where it is safe to fly during future eruptions.

Hundreds of flights were cancelled in 2010 and 2011 following volcanic activity in Iceland because of the danger that volcanic ash posed to aircraft and their engines.

In the new study, researchers studied volcanic ash recovered in the UK from the recent Eyjafjallajökull and Grímsvötn eruptions, as well as prehistoric samples from peat bogs in Yorkshire, Scotland and Ireland. Another sample, from an 1875 eruption, had been in a museum for 140 years.

The researchers found that grains were much larger than what had been typically estimated by satellite measurements of ash clouds – even moderately-sized eruptions could disperse large grains as far as the UK.

Volcanic ash particles from Icelandic eruptions extracted from peat bogs in Malham, Yorkshire, (pictures ‘a’ and ‘d’) and the Shetland Islands, Scotland (pictures ‘b’ and ‘c’). Credit: Atmospheric Measurement Techniques

Study co-author Dr Graeme Swindles, from the School of Geography at the University of Leeds, said: “Microscopic volcanic ash layers preserved in Yorkshire peat bogs and mud at the bottom of lakes, far from volcanoes, are providing much needed information on the characteristics of ash clouds. These records show us that Europe was hit by volcanic ash clouds very frequently in the past.”

The group also used computer models to simulate how clouds of various ash particle sizes would appear to satellite sensors. They found that sensors can underestimate the size of larger particles.

Dr John Stevenson, of the University of Edinburgh’s School of GeoSciences, who led the study, said: “Mapping volcanic ash clouds and their risk to aircraft is hard. Large regions of airspace can be contaminated by particles that are invisible to the naked eye. Combining the expertise of volcanologists and atmospheric scientists should help improve forecasts.”

Further information

The study was supported by the Scottish Government and Marie Curie Actions via the Royal Society of Edinburgh.

The research paper, ‘Big grains go far: understanding the discrepancy between tephrochronology and satellite infrared measurements of volcanic ash’, is published online in the journal Atmospheric Measurement Techniques on 19 May 2015.

Dr Graeme Swindles is available for interview. Please contact Sarah Reed, Press Officer at the University of Leeds, on 0113 34 34196 or email s.j.reed@leeds.ac.uk.


Disaster Charter activated for Villarrica volcano


A Red Alert has been declared in southern Chile after an eruption at Villarrica Volcano this morning.

Over two thousand people were evacuated from Pucon, and another thousand from Panguipulli, two communities close to the volcano.

While no one has been harmed in the eruption, the situation will continue to be monitored for any further eruption. The ash from the volcano could also pose a hazard to health. Meteorologists currently expect the ash cloud to be blown south and across remote parts of Argentina.

disaster_charterThe Disaster Charter is an agreement between international satellite and remote sensing agencies to provide free access to data and resources to help mitigate the effects of disasters on human life and property.

The Charter can be activated by any national disaster management authority. The activation for Villarrica was requested by the  Chilean agency responsible for civil protection (ONEMI, Oficina Nacional de Emergencia del Ministerio del Interior y Seguridad Pública).

For updates of the ongoing activity check the latest status reports from ONEMI, Chile. Also, follow #Villarrica on twitter for social media updates and more images of the current activity.

Chile’s Villarrica volcano spews fountains of lava

Chile’s Villarrica volcano erupted last night (Tuesday 3rd March) sending fountains of lava shooting into the sky. The eruption began at around 3am local time and is still ongoing.

Locals updated twitter with pictures of spectacular columns of lava and ash spewing out of the volcano crater. The Chilean agency responsible for civil protection (ONEMI, Oficina Nacional de Emergencia del Ministerio del Interior y Seguridad Pública) has declared a red alert indicating the volcano is still active and dangerous.


Villarrica is a pgmaps_Volcopular tourist destination and is one of the most active volcanoes in southern Chile. It has been producing gas almost constantly for 30 years since its last eruption in 1984. This recent eruption was preceded by signs of increased unrest around mid-February, which included increased seismicity and explosions around the crater. During an overflight on 16 February volcanologists observed a lava lake and recorded temperatures near 800 degrees Celsius.

The major hazard from this eruption to the local town of Villarrica is from lahars. These are extremely hazardous mudslides and form by the melting of snow and ice from the summit glacier by the intruding or erupting magma.

For status updates of the ongoing activity check the latest status reports from ONEMI, Chile. Also, follow #Villarrica on twitter for social media updates and more images of the current activity.


Webcam catches Colima volcano eruption

Earlier this week another big eruption occurred at the Colima volcano in western Mexico. The volcano has been erupting for the past few weeks, but this latest eruption was caught on a webcam.

The video has been sped up but shows the power of the eruption as it spews out ash some 2000m into the atmosphere above the summit.