SEATTLE - Officials plan to upgrade a volcanic mudflow warning system for Mount Rainier.

Scientists say the upgrades could detect trouble sooner and give southeastern Puget Sound residents more time to evacuate.

Scott Heinze of Pierce County's emergency-management department tells the Seattle Times in a story on Monday that projections show up to 500 million cubic meters of debris could break loose.

Officials say a significant mudflow 5,600 years ago filled the valleys of the White River up to 300 feet with sediment in the area that now includes Sumner, Enumclaw and Auburn.

Officials say they want to increase the number of places with detection technology as well as install a volcanic-monitoring network that could provide weeks or months of advance warning.