363 BB tons / (1 ton / cu m) / (1 BB cu m / cu km) is the mass of a 9-km-diameter ice ball, smaller for rockier materials.
363 BB tons / 10 years = 100 MM tons / day.
By comparison, Mount St Helens (1980) and Eyjafjallajökull (2010) each produced 500 MM tons of ash. So the amount of material is about equivalent to having a similarly-sized volcano eruption every few days for ten years straight.
The Earth's surface area is 500 MM sq km. If we were to distribute 363 BB tons uniformly, that would be an average of 1000 tons per sq km. If the layer had a density of 1 ton per cu m (same as water), the resulting layer would be 1/1000 of a meter thick. This seems to be thinner than the spherule layers described.
We're assuming an even average distribution, and comparing ash to spherules - which would have different patterns of sedimentation depending on how far from epicenter one is. Although, for a large enough impact, the distribution radii overlap around the planet so there may be quite a bit of averaging as the sun+atmosphere provides a mixing medium and the energy to do so.
363 BB tons / (1 ton / cu m) / (1 BB cu m / cu km) is the mass of a 9-km-diameter ice ball, smaller for rockier materials.
363 BB tons / 10 years = 100 MM tons / day.
By comparison, Mount St Helens (1980) and Eyjafjallajökull (2010) each produced 500 MM tons of ash. So the amount of material is about equivalent to having a similarly-sized volcano eruption every few days for ten years straight.
The Earth's surface area is 500 MM sq km. If we were to distribute 363 BB tons uniformly, that would be an average of 1000 tons per sq km. If the layer had a density of 1 ton per cu m (same as water), the resulting layer would be 1/1000 of a meter thick. This seems to be thinner than the spherule layers described.