A powerful hydrothermal explosion rocked Yellowstone National Park’s Biscuit Basin on Tuesday morning, sending a geyser of steam, rock, and mud high into the air and prompting visitors to flee in panic. The unexpected eruption occurred around 10:19 a.m. local time near Sapphire Pool, a popular hydrothermal feature located about two miles northwest of the iconic Old Faithful geyser. Eyewitness videos captured the dramatic scene as the ground rumbled and a dark column of debris shot skyward, raining down on the surrounding boardwalk and trails. Park officials confirmed that no injuries were repo…