Question 3. (2 marks) An organic sample from a Chinchorro mummy was found to con- tain 54.29% of the relative proportion of carbon-14 found in living matter and the atmosphere. Approximately how long before the carbon-14 measurements were made had the mummy been buried? (The half-life of carbon-14 is 5730 years.) Question 4. (3 marks) Earthquake magnitude, M, on the Richter scale is defined by: M = log10 where I is the corresponding intensity of the earthquake in cm according to seismograph readings taken 100 km from the epicentre of the earthquake and S = 10-* cm is the intensity associated with a standard earthquake. The most desctructive earthquake in contemporary Australian history occurred in Newcastle, NSW, in 1989. The earthquake had a magnitude of 5.6. (a) Assuming seismograph readings were taken 100 km from the epicentre of the earthquake, what was the corresponding intensity of the earthquake (measured by the amplitude of a seismograph reading in centimetres)? (b) The 1960 Valdivia earthquake was the most powerful earthquake ever recorded. Its approximate intensity was 3.1623 x 10" cm. What was the magnitude of this earthquake on the Richter scale? (c) How many times more intense than the 1989 Newcastle earthquake was the Valdivia earthquake