Landers Quake

This particular quake was scientifically significant because it was the first documented case of one quake being causal to another (the Big Bear quake which occured a short time later).

(1) What can I say? I just like helicopters.
(2) Looks vaguely like me and Gail, but younger, thinner and (in my case) hairier.
(3) Nothing to do with the earthquake, this was an early SCE solar power test plant (collector tower with concentric rings of focusing mirrors).
(4) Ground rupture – vertical displacement three to four feet.

(5) Near center of rupture zone, displacement of six or more feet, I think. Note low eroded hills on high side of fault, flatter ground on low side. Classic example of previous uplift and subsequent erosion.
(6) Rupture zone extends from lower left to upper right. Note lateral displace of road where crossed by fault. Hills in previous photo at upper right.
(7) Close-up of road displacement. Probably a USGS truck at site. Lateral displacement occurs over a distance of 100 feet or more in a series of surface ruptures, as opposed to one clean break. Actually easier to see from a distance. This is because the actual rock fracture is below many feet of sand alluvium. (It occurs to me that this could be recreated in the classroom with a tray of moist sand and a split sliding base).
(8) Another shot near area in Photo 5. Note small branch rupture trending toward upper left.

(9) Another angle of road displacement. Darker band angling is main fracture and involved some vertical displacement as well.
(10) Another road displacement, photo taken from low side of fault. Near side is now several feet lower than far side. Example of simultaneous vertical and lateral displacement.
(11) Surface rupture is just above houses at intersection, thin dark line.
(12) Another view of valley floor rupture in Photo 6.

(13) Note road displacement. Look closely and you can see a collapsed steel power transmission tower between the two temporary power poles. Unfortunate placement!
(14) Another angle on Photo 10.
(15) Close-up of collapsed tower. That dirt road used to be straight.
(16) Rupture traverses pocket of soft sand in dry wash. Notice how surface disturbance is dispersed in loose material.

(17) I suspect there was a lot of damage in these homes!
(18) Main rupture at center of photo. Several minor ruptures can be seen branching away from the main rupture, diverging toward right.
(19) Emergency road repair where surface rupture broke the pavement.
(20) Wow! On a more analytical note, I expect that the slope to the right of the fracture is the total fault scarp, the result of many such quakes.

(21) Displacement visible on both fence and road.
(22) Quake really trashed this house – no, wait, it was like that before!