NEWS SCOOP: By comparing the news (aerial coverage photos), I was able to locate on Google Maps the location of ground zero of the explosion crater (Glenview Dr./Earl Av. intersect): http://maps.google.com/maps?hl=en&i...622541,-122.441934&spn=0.000264,0.000431&z=21 There appears to be "freshly-paved**" excavations at the location (both in the "Earth" and "Satellite (new 45 degree)" mode photos. **(Depending on the dates of when the photos where taken, that is, to determine how fresh the excavations are). You heard it first at : SciForums
They have already said that it was a underground natural gas pipe that blew up so we know what caused the explosion. The reason it exploded isn't known as yet but I'll bet someone didn't repair the pipe at that intersection correctly. Only time will tell and we may never hear of the results of the investigation into why this pipe ruptured and blew. What is strange is that people there should have smelled a gas oder in the air and they should have reported that oder when they did smell it.
Its was stunning to see planes/helicopters dropping water on this residential area. You usually only see it over forests
EARTHQUAKE ON SITE OF GAS LEAK AT TIME OF EXPLOSION Magnitude: 1.1 Date-Time:Thursday, September 09, 2010 at 06:11:12 PM at epicenter Location: 37.623°N, 122.442°W Depth: 0 km (~0 mile) (poorly constrained) Distance: 1 km (1 miles) WSW (258°) from San Bruno, CA** http://earthquakes.usgs.gov/earthquakes/recenteqsus/Quakes/nc71453305.html **courtesy: U.S. Geological Survey Another SciForums exclusive
Good questions. According to USGS: "...An earthquake cannot occur at depth of 0 km. In order for an earthquake to occur, two blocks of crust must slip past one another..." From the same source: "...Analysis of local seismic recordings (within a couple of miles) of nuclear tests at the Nevada Test Site shows that some tectonic stress is released simultaneously with the explosion. Analysis of the seismic wavefield generated by the blast shows the source can be characterized as 70-80 percent dilational (explosive-like) and 20-30 percent deviatoric (earthquake-like)..." The seismic reading gives an interesting "timing stamp" of the time of explosion, but a follow-up of further activity in that area of the San Andreas fault zone verifies no further activity following the event: http://earthquakes.usgs.gov/earthquakes/recenteqscanv/FaultMaps/122-37.html