LIVE UPDATES: Tsunami warnings, watches, advisories were given to 1/4 of the Earth after 8.8 quake

U.S. Secretary of Homeland Security Kristi Noem said the threat of a major tsunami hitting the United States "has passed completely."

Noem, speaking in Chile where she is attending meetings with officials, told reporters in the capital, Santiago: "We're in really good shape right now. We were fully deployed and ready to respond if necessary, but grateful that we didn't have to deal with the situation that this could have been."

The Tsunami danger appeared to also be lessening with authorities in Hawaii and parts of Japan and Russia downgrading their warnings.

Russian authorities on the Kamchatka Peninsula and Kuril Islands have canceled their tsunami warnings but say the risk of aftershocks and waves remains.

The regional branch of Russia's Emergency Ministry on Kamchatka warned that scientists expect aftershocks at magnitudes of up to 7.5. It said that more tsunamis are possible in the Avacha Bay where the regional capital of Petropavlovsk-Kamchatsky is located.

If you have a flight to Hawaii on Wednesday, check the status before you go.

Honolulu International Airport is recovering from all flights being stopped temporarily Tuesday night after the tsunami was triggered.

According to Flight Aware, two United flights from SFO and a Southwest flight from San Jose were turned around and returned to the Bay Area.

Honolulu's airport is reporting multiple delays and cancellations on Wednesday morning.

Tsunami waves reached the San Francisco coast early Wednesday morning, according to the National Weather Service, as California coastal communities continue to monitor rising wave activity following a massive offshore earthquake off Russia.

The initial tsunami activity in San Francisco was detected at 1:12 a.m., the NWS said on social media posts.

The Northern California tsunami activity began in Crescent City and Humboldt Bay around 12:45 a.m. Tsunami waves then reached Monterey at 12:50 a.m.

Forecasters warn that waves will likely build through the night and become more dangerous near high tide. No major damage has been reported, as of 1:30 a.m.

The National Tsunami Warning Center issued a Tsunami Advisory on Tuesday evening after a powerful 8.7 magnitude earthquake struck off the coast of Russia's Kamchatka Peninsula. The advisory covers coastal areas from Mendocino County to Monterey County.

The California Governor's Office of Emergency Services has deployed rescue teams to Del Norte and San Luis Obispo counties.

Tsunami activity continued to build in northern California as high tide approached Wednesday morning with maximum confirmed heights along the coast of 3.6 feet in Crescent City, 3.0 feet in Arena Cove and 1.2 feet in Humboldt Bay, according to the National Weather Service office in Eureka.

The measurements in Crescent City and Arena Cove were high enough to create minor coastal flooding and inundation, the weather service said on social media, adding that tsunami activity will persist and people should avoid beaches and harbors.

Crescent City officials warned on social media that higher surges could arrive around high tide and could affect lower-lying areas.