It will almost certainly take several tens of thousands of years, if the growth rate for L'ihi is comparable to that of other Hawaiian volcanoes (about 0.1 foot per year averaged over geologic time).
A: The Richter scale is used to quantitatively measure the magnitude of an earthquake. This tool was devised by the seismologist Charles F. Richter in 1935. Full Answer >
In other words, a magnitude 7 earthquake would produce seismogram waves 10 x 10 = 100 times as high and release energy 32 x 32 = 1024 times as great as a magnitude 5 earthquake. The Richter scale is open-ended, meaning there is no limit to how small or large an earthquake might be.