Srednii volcano is a mostly submarine volcano in the central Kurile Islands between Rasshua and Ushishir Islands. Only a few rocks and islets breach the surface of the sea, including flat-topped Khitraya Rock, which could be a young lava dome or the rim of an old caldera.
The volcano with its reefs and small surfacing rocks is a hazard to ships in the strait.
Steamboat Springs is a volcanic field of rhyolitic lava domes located 20 km SSE of Reno, Nevada. It is between 2.5 and 1.1 million years old and consists of lava domes and flows.
There are no recent eruptions, but it is hydrothermally very active, and contains about 50 hot springs, steam vents, and fumaroles.
An swarm of small earthquakes occurred 25 km NE of the Steamboat Springs in May 2008.
Steve Axford is a full time photographer based in Melbourne Australia. He joined VolcanoDiscovery on many trips in Indonesia and in Africa and became a team member in 2006. -> See whole entry
Stromboli, a small island north of Sicily, is one of the most active volcanoes in the world and famous for its normally small, but regular explosions throwing out glowing lava from several vents inside its summit crater. This activity has been going on for at least 2000 years, as long as there is written memory of the activity, which Stromboli lended its name to, the so-called strombolian activity. -> See whole entry
Suiyo is an active submarine volcano forming one of the Shichiyo Seamounts, which are named for the 7 days of the week and are located south of Sofugan volcano. Suiyo ("Wednesday") is an basaltic-to-dacitic submarine volcano with a caldera and lava dome that rises about 1400 m from the sea floor to within 1418 m of the sea surface.
The summit caldera is 1.5 km wide and about 500 m deep. Major hydrothermal activity was observed in July 1991, with temperatures reaching more the 290 degrees C, and the volcano was reclassified as active by the Japan Meteorological Agency.
Sukaria is a poorly known caldera in central Flores Island, NE of Iya volcano. The caldera measures 8 km in diameter and has 750-m-high northern walls, rising above the village of Sukaria, which lies in the center of the caldera.
The southern caldera walls are irregular. Fumaroles and small geysers occur on the western flank.
Sumaco is an active stratovolcano east of Antisana, ca. 100 km east of Quito. It is an isolated mountain about 50 km east of the main volcanic range and rises 2800 m above the western Amazon basin. The volcano contains a 300 x 400 m wide summit crater with a central cone inside. There are 3 reports of eruptions in historic times, but only one eruption around 1895 is believed to actually have taken place. -> See whole entry
The large Sumbing volcano in Central Java west of Merapi dominates the landscape between Yogyakarta and the Dieng plateau. It is not certain wether the volcano has erupted in historic times, but it is considered one of Indonesia's active volcanoes. The summit of Sumbing contains an 800 m wide crater breached to NE where a geologically young lava dome was built feeding a lava flow down to 2400 m elevation.
Note: another volcano called Sumbing is found on Sumatra. -> See whole entry
Sumiyoshi-ike volcano refers to 2 maars 2 km apart located in the coastal lowland north of the Aira caldera: Sumiyoshi-ike (500 m diameter) and Yonemaru (1.2 km).
The maars erupted when sea level was rising about 8,000 years ago (Sumiyoshi-ike) and 6500 years ago (Yonemaru). The larger of the two, Yonemaru, produced pyroclastic surges that traveled 4 km from the crater.
Sunset Crater in northern Arizona is one of the youngest volcanoes in the USA. It is named for its brilliantly colored scoria deposits on the cone and only one of more than 550 vents of the vast San Francisco volcanic field.
The last eruption took place sometime between about 1080 and 1150 AD.
In the late 1920s, a Hollywood filmmaker planned to use Sunset Crater as movie set and use dynamite to simulate an eruption, but local resistance stopped these plans. -> See whole entry
Suwanose-jima (諏訪之瀬島) volcano is Japan's and one of the world's most active volcanoes. It has been in a state of near-continuous strombolian-type eruption since 1949.
The volcano forms the 8 km long spindle-shaped island of the same name in northern Ryuku Islands, Japan. The remote island is home to about 50 residents only.
Suwanose-jima consists of an andesitic stratovolcano with 2 historically active summit craters. Intermittent to continuous strombolian activity began from On-take (Otake), the NE summit crater, in 1949 and has been going on since. After 1996, occasional periods of inactivity have become more frequent. -> See whole entry
