As four US volcanoes are at elevated risk or have a WATCH / ORANGE status due to recent volcanic activity, the USGS will continue to monitor them throughout this holiday weekend.

The Great Sitkin Volcano, Semisopochnoi, Pavlof, and Kilauea are the four US volcanoes. Mount Cleveland and Mauna Loa volcanoes both received an ADVISORY/YELLOW status. Other volcanoes that USGS is keeping an eye on are all currently GREEN or unrated.

According to experts, the ongoing earthquake swarms that have been occurring in South Carolina, Missouri, and Puerto Rico are not currently connected to volcanic eruptions.

Monitoring Authorities

The USGS keeps tabs on 161 volcanoes that could be active within the country. At any given time, there are typically about two dozen volcanoes erupting worldwide, according to USGS. Around 500 of the 1,500 volcanoes that are potentially active around the world have erupted in recent memory.

More than 130 volcanoes and volcanic fields can be found in Alaska. Hawaii is another location well-known for its volcanoes. The Hawaii Volcano Observatory (HVO) keeps track of the volcanoes in Hawaii, while the Alaska Volcano Observatory keeps track of the volcanoes in Alaska (AVO.) The California Volcano Observatory, Cascades Volcano Observatory, Yellowstone Volcano Observatory, and Northern Mariana Islands Volcano Observatory are additional observatories to the AVO and HVO.

Aviation Codes and Volcanic Activity Alert Levels are published by the USGS and volcano observatory units. Green, yellow, orange, or red is the different aviation codes.

The USGS also keeps track of the numerous volcanoes in the western United States. Volcano observatories have been established in Yellowstone, the Cascades, and California.

Great Sitkin Volcano, Alaska (ORANGE)

A member of the Andreanof Islands group in the central Aleutian Islands, the Great Sitkin Volcano is a basaltic andesite volcano that takes up the majority of Great Sitkin Island's northern half. It is 1,192 miles southwest of Anchorage and about 26 miles east of Adak.The volcano has a composite structure made up of a younger parasitic cone with a summit crater that is 1.8 miles in diameter and an older dissected volcano. The crater's interior is dominated by a lava dome with a steep incline that was created during an eruption in 1974. Currently, USGS warns, that explosive activity could occur with little or no warning.

Semisopochnoi, Alaska (ORANGE)

Just 9.7 miles west of Alaska's 180th Meridian, Semisopochnoi is the most easterly land in both North America and the United States. The Aleutian Islands, a group of 14 sizable volcanic islands, include Semisopochnoi. The USGS adds a warning that small explosions and related ash emissions might continue and be challenging to find, particularly when dense cloud cover hides the volcano and 55 other smaller islands.

Pavlof, Alaska (ORANGE)

A stratovolcano called Pavlof Volcano is situated on the southwest tip of the Alaskan Peninsula, less than 600 miles from Anchorage. The volcano has active vents close to the summit on its north and east sides, which have a diameter of about 4.4 miles. One of the Aleutian Arc's most frequently active volcanoes, the volcano has experienced more than 40 historic eruptions. The Aleutian Arc is located on the Pacific Ring of Fire. The progression to more significant eruptive activity can occur with little or no notice, according to the current AVO warning.

Kilauea, Hawaii (ORANGE)

The only erupting volcano in the United States that attracts tourists is Kilauea Volcano. USGS and HVO do issue warnings about the dangers present there even though Hawaii and the national park where the volcano is located are welcoming to visitors.

The current eruption at Kilauea's summit is taking place within a portion of Hawaii Volcanoes National Park that is off-limits. High volcanic gas concentrations are the main threat because they can have a significant impact downwind.

Visitors to the nearby Kilauea Volcano and Hawaii Volcano National Park are urged by HVO and USGS to always proceed with extreme caution.

Read also: Volcanic Eruption: New Study Finds Water Affects Magma Depth 

Mauna Loa, Hawaii (YELLOW)

With a height of 13,681 feet above sea level, Mauna Loa is regarded as the planet's largest active volcano. At a depth of about three miles, Mauna Loa rises from the Central Pacific ocean floor. The ocean floor directly beneath Mauna Loa is depressed by an additional 5 miles due to the volcano's size and mass.

The massive volcano, also referred to as the "Big Island of Hawaii," spans half of the Hawaiian island.

HVO warns that communities on the east and west sides of the Big Island, from Kona to Hilo, may be affected by the large, swiftly moving lava flows that frequently result from Mauna Loa eruptions.

Cleveland Volcano, Alaska (YELLOW)

A stratovolcano named Mount Cleveland or Cleveland Volcano is situated in Alaska's Islands of Four Mountains group of the Aleutian chain. It is symmetrical and 5,676 feet tall. Cleveland, one of the Aleutian Arc's most active volcanoes, has erupted at least 22 times over the past 230 years. Cloudy conditions otherwise obstructed satellite views, AVO noted, adding that Elevated surface temperatures in the summit crater were seen in satellite data over the past 24 hours. There was no discernible infrasound activity on local or regional networks, Weatherboy reports.

Related article: USGS Discovers Growing Bulge Near Three Sisters Volcano Due to Increased Seismic Activity