Impact specifics
The impactor's estimated size was about 10 km (6 mi) in diameter and is estimated to have released 4×1023 joules of energy (95,602,294,455 kilotons of TNT on impact). By contrast, the most powerful man-made explosive device ever detonated, the Tsar Bomba, had a yield of only 50 megatons, making the Chicxulub impact 2 million times more powerful. Even the largest known explosive volcanic eruption, which released approximately 1021 joules and created La Garita Caldera, was substantially less powerful than the Chicxulub impact.
Effects
The impact would have caused some of the largest megatsunamis in Earth's history, reaching thousands of feet high. A cloud of super-heated dust, ash and steam would have spread from the crater, as the impactor burrowed underground in less than a second. Excavated material along with pieces of the impactor, ejected out of the atmosphere by the blast, would have been heated to incandescence upon re-entry, broiling the Earth's surface and possibly igniting global wildfires; meanwhile, colossal shock waves would have effected global earthquakes and volcanic eruptions.The emission of dust and particles could have covered the entire surface of the Earth for several years, possibly a decade, creating a harsh environment for living things. The shock production of carbon dioxide caused by the destruction of carbonate rocks would have led to a sudden greenhouse effect. Over a longer period of time, sunlight would have been blocked from reaching the surface of the earth by the dust particles in the atmosphere, cooling the surface dramatically.