In April 1815, the most powerful volcanic blast in recorded history shook the planet in a catastrophe so vast that 200 years later, investigators are still struggling to grasp its repercussions. It played a role, they now understand, in icy weather, agricultural collapse and global pandemics — and even gave rise to celebrated monsters.

Around the lush isles of the Dutch East Indies — modern-day Indonesia — the eruption of Mount Tambora killed tens of thousands of people. They were burned alive or killed by flying rocks, or they died later of starvation because the heavy ash smothered crops.

More surprising, investigators have found that the giant cloud of minuscule particles spread around the globe, blocked sunlight and produced three years of planetary cooling. In June 1816, a blizzard pummeled upstate New York. That July and August, killer frosts in New England ravaged farms. Hailstones pounded London all summer.

A recent history of the disaster, “Tambora: The Eruption that Changed the World,” by Gillen D’Arcy Wood, shows planetary effects so extreme that many nations and communities sustained waves of famine, disease, civil unrest and economic decline. Crops failed globally.