美国国家气象局：加州北部海啸活动持续增强

Core Viewpoint - The article discusses the impact of a strong earthquake off the coast of Russia on tsunami activity along the northern coast of California, highlighting the observed wave heights and ongoing warnings from meteorological authorities [1]. Group 1: Tsunami Activity - The National Weather Service reported that tsunami activity has intensified along the northern coast of California due to the earthquake [1]. - Maximum wave heights recorded include 1.1 meters in Crescent City, 0.9 meters in Arena Cove, and 0.4 meters in Humboldt Bay [1]. - The observed values in Crescent City and Arena Cove are sufficient to trigger minor coastal flooding and seawater inundation [1]. Group 2: Public Safety and Warnings - The public is advised to stay away from beaches and ports as tsunami activity is expected to continue [1]. - Following the initial tsunami waves reaching Hawaii and the West Coast, the Pacific Tsunami Warning Center downgraded the alert level for the Hawaiian Islands to "tsunami warning" [1]. - The Governor of Hawaii stated that no significant waves have been observed yet, but warned of the possibility of more tsunami waves in the future [1]. Group 3: Current Alerts - As of the morning of July 30, the National Oceanic and Atmospheric Administration (NOAA) continues to issue tsunami warnings for Alaska, Oregon, Washington, and California [1]. - The tsunami warning remains in effect for the area from Mendocino County north to the Oregon border [1].