JAPAN SEIZED a record 30.2 pounds of cocaine in 1989, a 64-fold increase over the preceding year, the Justice Ministry reported . . . A MODERATE EARTHQUAKE measuring 4.7 on the Richter scale struck the Canadian province of Quebec early Friday and was felt in parts of the northeastern United States, officials said . . . U.S. JET FIGHTERS intercepted two Soviet bombers flying over the Bering Sea southwest of the Alaska mainland and steered them back toward Siberia, the Air Force said Thursday. It was only the third time this year that Soviet bombers have been encountered on apparent training missions on the periphery of Alaska, an event that was almost a routine occurrence until the recent warming in U.S.-Soviet relations.