c# decode qr code IV V in Visual C#

Decoder QR Code in Visual C# IV V

50 59

60 69

The Richter Magnitude Scale was developed in 1935 by Charles F Richter of the California Institute of Technology to compare earthquakes Using high-frequency data from nearby seismograph stations, Richter could measure an earthquake s magnitude (size) Each logarithmic magnitude rise in the Richter scale represents a tenfold increase in energy Table 52 lists increasing earthquake magnitudes and effects Earthquakes with a magnitude of 20 or less are often called microearthquakes Most people don t feel them and only nearby seismographs record their movement Earthquakes of 45 or greater magnitudes (thousands each year) are recorded by sensitive seismographs worldwide On average, one large earthquake of >80 occurs somewhere in the world yearly The 2004 Sumatra undersea earthquake had a magnitude of 92

Today s digital monitoring instruments use waveforms to record and analyze seismic data The 2004 Sumatra deep ocean earthquake caused seismographs to record seismic waves traveling all around the Earth in free oscillation Resulting from a 1,200 km long section of the Indian

Before quake Primary wave starts (lasts ~20 seconds)

Ocean floor sliding under the Southeast Asian Continental Plate, the seismic waves rattled the Earth for days Over 300,000 people from 40 nations were reported dead or missing from the resulting tsunamis that hit Indonesia, India, and western Africa Millions were homeless

There are two types of seismic waves, body waves and surface waves Body waves travel through the Earth s interior, while surface waves travel the top surface layers Most earthquakes take place at depths of less than 80 km below the Earth s surface Body waves are further divided into P waves and S waves Figure 55 shows a typical earthquake tracing Primary waves Primary (P) waves, which bunch together and move apart like an inchworm, are the fastest seismic waves, moving 5 km/s (14 times faster than sound waves move through air) to arrive at a monitoring station P waves are longitudinal compression waves Like sound waves, they travel through rock or buildings, causing squeezing and expanding parallel to the direction of transmission The speed of a P wave depends on the types of matter through which it moves Generally, the denser the matter, the faster the P wave travels Secondary waves Secondary (S) waves travel around 60% of the speed of P waves and arrive at monitoring stations later S waves are transverse shear waves They cause a shearing, side-to-side motion perpendicular to their travel direction Because of this, they can only travel through material (eg, rock) with shear strength Liquids and gases have no shear strength, so S waves can t travel through water, air, or molten rock

Since a seismogram indicator jumps wildly with P wave action, it can be tricky to spot lower frequency and longer wavelength S wave arrival A sudden wavelength increase and amplitude jump indicates an S wave However, when a large earthquake occurs, this isn t obvious, because P wave action hasn t slowed to the point where S waves overwhelm it

Surface waves are further divided into Love waves and Rayleigh waves These waves travel along the Earth s surface and produce distinct types of motion Love waves produce motion at a 90 degree angle to the wave s direction This causes the horizontal shearing that wipes out building foundations Rayleigh waves produce a lazy rolling motion, causing buildings to experience a bobbing motion transverse to or parallel to a wave s direction of travel This rolling, elliptical action is extremely hard for non-earthquake-proof buildings to withstand

Magnitude measures the energy released at the earthquake s source and is determined by seismograph measurements Magnitude is the same no matter where you are or how strong or weak the shaking is in different locations In the Richter Magnitude Scale, the amount of movement (amplitude) caused by seismic waves determines its magnitude