The restriction on flights across much of Europe has saved Anglo American from a showdown with angry protesters at its annual general meeting today, but the mining giant will still be confronted over its exploration activities in Alaska.
Anglo American was bracing itself for a demonstration by native community leaders, who are angry at the group's exploration in the Bristol Bay area. The local people say that a mine would destroy fisheries, which residents rely on for their way of life.
A delegation had planned to deliver a petition, which has been signed by 100,000 people, but the spread of the Icelandic ash cloud has prevented a delegation from attending the meeting. A local representative will go to the AGM instead.
"Not even a volcano will keep us from holding Anglo American executives to promises not to build Pebble Mine over the objections of local people," said Bobby Andrew, an Alaskan native leader who was due to address Anglo's shareholders. "Our culture and the wild salmon fishery that sustains it are at stake. Anglo American is pursuing the mine despite commitments the company has made and over the clear objections of an overwhelming majority of local people."
Verner Wilson, who will deliver the petition, is an Anglo shareholder and says he will use the meeting to ask the chief executive, Cynthia Carroll, if she will keep a promise not to develop the mine in the face of local opposition.
Anglo American, and its 50 per cent joint venture partner in the exploration project, Northern Dynasty, a Canadian company, says that it has undertaken not to build a mine, "if it cannot be done in a safe and responsible way".
The Alaskans say that the mine will disrupt local fisheries in Bristol Bay, which produces about half of the world's supply of wild sockeye salmon. The UK imported $43m (£28m) worth of sockeye from the Bay last year. Mr Wilson argues that the fisheries have provided a way of life for the local people for 7,000 years.
Despite Anglo American's assurances, the protesters say that because of the amount of money already spent on the exploration, about $323m, and because the Pebble site has already uncovered significant supplies of iron ore, gold and copper, the miner is unlikely to want to give up on the project. Anglo does not dispute the amount that has already been spent on the project, but says that it is too early to make any long term decisions about the viability of the site.
It adds that the area already being excavated is on land set aside by the Alaskan authorities for mining.