Quake - East of Sacramento

[GalvestonDuck]

At 05:23 PST USGS reporting a 4.5 quake 160 miles east of Sacramento, CA.

[Josephine96]

Lot of earthquakes the last few days

[Tornado_Chaser2005]

Ive been studying this section of quakes Galvstonduck, and Ive noticed that all of them are in the general area of Mammoth Mountain. I well known volcanic area near the CA/NV border in Northern Central California. just 2 weeks ago this area had a 5.0 magnitude! Something is going on under mammoth I think.

[Rainband]

Mother nature has sure been active this year!!

[Brent]

Hmmmmm..........

[CaptinCrunch]

USGS responds to Volcano Activity and New Unrest in Alaska, Washington, and Hawaii

Scientists are responding to several volcanoes in the United States that are erupting or showing signs of restless activity in order to provide up-to-date hazard assessments and warnings of potential eruptions to the public. See current updates for the latest.

A small explosive eruption of Mount St. Helens on October 1—the first in more than a decade—followed a week of increasing earthquake activity beneath the volcano and deformation of the lava dome. This eruption sent a steam and minor ash plume to an altitude of about 10,000 feet above sea level. Two days earlier on September 29, scientists of the USGS Cascades Volcano Observatory and University of Washington Geophysics Program issued a Volcano Advisory. See the current update for the latest information on the status of the volcano.

In Alaska, a swarm of earthquakes 2 to 3 km beneath the summit cone of Mount Spurr volcano, located 130 km west of Anchorage, was first noticed in early July by scientists of the Alaska Volcano Observatory (AVO). Aerial reconnaissance in mid-July and early August revealed recent small flows of mud and rock and a new "ice cauldron" in the summit ice cap. The ice cauldron is a collapse feature possibly caused by an increase in heat coming from deep beneath the summit. Scientists have also measured volcanic gases escaping from the summit cone. See current information about Spurr. The most recent eruption of Spurr occurred in 1992 (see summary of the 1992 eruption precursors and the eruption warnings and public statements issued by AVO.

AVO scientists are also monitoring closely the continuing eruption and restless activity at Veniaminoff and Shishaldin volcanoes.

The ongoing eruption of Kilauea Volcano, Hawaii, continues to capture the attention of scientists from the USGS Hawaiian Volcano Observatory as lava flows spread from the active vent, Pu`u `O`o (see eruption update). In late July, a swarm of deep (>40 km) earthquakes beneath nearby Mauna Loa volcano was detected by HVO scientists. Beginning in April or early May 2002, a GPS network on the volcano showed definite lengthening of the lines across the summit caldera, indicating the volcano was inflating after nearly 10 years of slight deflation. Scientists infer that the volcano's magma reservoir is swelling with new magma. This past summer, HVO scientists have worked to install new GPS instruments and upgrade seismic stations on the volcano. See Mauna Loa current activity from HVO.

[CaptinCrunch]

ABBREVIATED COLOR CODE KEY (contact AVO for complete description):
GREEN volcano is dormant; normal seismicity and fumarolic activity
occurring
YELLOW volcano is restless; eruption may occur
ORANGE volcano is in eruption or eruption may occur at any time
RED significant eruption is occurring or explosive eruption expected at any
time

[CaptinCrunch]

Mount St. Helens Update, October 9, 2004, 5:30 p.m, PDT

Current status is Volcano Advisory (Alert Level 2); aviation color code ORANGE

Seismic activity has remained at a moderate, but variable rate. Currently earthquakes up to magnitude 2 are occurring at a rate of about 1 every two to three minutes minutes. No visual observations of the crater, the 1980-86 lava dome, or the intensely deforming and uplifting area on the south side of the dome were possible today due to low clouds. No scientists worked in the field today.

Additional analysis of lidar and photographs of the intensely uplifting area on the south side of the lava dome suggests that the total volume change represented by the deformation between late September and October 6 is about 16 million cubic meters (21 million cubic yards). The average rate of change is about 2 million cubic meters per day (2.6 million cubic yards per day). If this figure represents the rate of intrusion of magma into shallow levels of the dome and(or) underlying crater floor, it is an intrusion rate about twice that measured during dome-building eruptions at Mount St. Helens in the 1980s.

As a result of the intense unrest of the past 11 days, we infer that magma is at a very shallow level. During times of unrest, Mount St. Helens and similar volcanoes elsewhere typically go through episodic changes in level of unrest over periods of days to weeks, or even months. Such changes are in part driven by variations in the rate of magma movement. We expect fluctuations in the level of unrest to continue during coming days. Escalation in the degree of unrest and perhaps an eruption could occur suddenly or with very little warning. There may be little time to raise the alert level before a hazardous event occurs. Therefore, we continue to monitor the situation closely and will issue additional updates and changes in alert level as warranted.

[Wnghs2007]

Lordie Mercy, This year has been quite the year hasnt it.