How to Read the Display. The seismograms displayed are from a few of the seismograph stations routinely recorded by the Northern California Seismograph Network. Each is a record of how the ground moved at a particular seismograph station in Northern California during a 24-hour period.he height of the recorded waves on the seismogram (wave amplitude) is a greatly magnified representation of the actual ground motion. A recording of an earthquake has recognizable characteristics.
View Full Profile. There are three main causes of retinal detachment, each with its own set of risk factors. The most common type is called a ârhegmatogenousâ detachment, and is caused by a tear or hole in the retina. The retina is the thin, light-sensitive tissue that lines the back inside wall of the eye.
Retinal detachment can progress quickly. Because retinal detachment affects side (peripheral) vision first, you may not notice the vision loss right away. If not treated, detachment can spread to the center of the retina (macula) and damage central vision. Retinal detachment requires urgent care. Without treatment, vision loss from retinal detachment can progress from minor to severe or even to blindness within a few hours or days. Retinal tears and holes, though, may not need treatment. The retina sometimes develops small, round holes as it ages, and many of them will not lead to retinal detachment.