Do Trains Help Relieve Stress From Earthquake Faults?

Posted by on November 9, 2011 No comments

The other day, I was talking to a geologist in our area, and I live near the San Andreas Fault in California. We talked about the challenges with liquefaction because there is quite a bit of sand around here with groundwater underneath. It could be quite problematic if there were a 10.0 earthquake. It is doubtful that the entire San Andreas Fault would go all at once, but the fault is long enough to produce a magnitude 9 earthquake.

That’s scary stuff when you think about it. Now then, I have a non sequitur, and thought I’d like to share with you today if you have a few moments.

Since trains produce vibrational energy which can be viewed on a Richter scale, often in the neighborhood of 1.2 to 2 magnitude, then essentially that is creating lots of little earthquakes, let’s call them swarms of earthquakes every time the train goes by. The train runs up and down the San Andreas Fault in California in some parts. In doing so it jiggles the Earth, and allows the sand to settle. As the sand settles it becomes more compacted with less space in between the granulars, over time this would cause the ground elevation to lower. Interestingly enough many of the cities near where I live are around 10 feet less in elevation than they were 30 years ago. Read more »

Action Potential and Neurotransmission

Posted by on March 9, 2011 No comments

Nearly all cells maintain a voltage difference between their interior and exterior environment. The voltage of the cell is measured in milli volts (mV). The voltage of a typical animal cell is -70 mV. In majority of cells very little voltage fluctuations are known to occur but in some cells this is a usual feature. Some cells also show up and down cycles as the voltage increases and declines. The duration of these potentials vary over a wide range. In brain cells, the up and down cycle of action potential are completed in less than thousandth of a second while in other types of cells the cycles may take several seconds. The electrical property of an animal cell is dependent upon the membrane structure. Cell membrane is made up of a layer of lipids and proteins. The lipid layer acts as an insulator.

Generation of action potential within a neuron

All animal cells are electrically polarized as they maintain a voltage difference known as membrane potential. In case of neurons, axons, dendrites and cell body have different electrical properties. The most excitable part of a neuron is the axon hillock but axon and cell body also become excited. At the axon hillock the resting potential is -70 mV and the threshold potential is -55 mV. Synaptic inputs to the neuron result in depolarization causing the membrane potential to rise or fall. Action potential is produced when enough depolarization accumulates and the membrane potential reaches a threshold value. Read more »