WEBVTT 00:00:00.100 --> 00:00:04.200 did you know that the Earth has a pulse ideological pulse that 00:00:04.200 --> 00:00:04.500 is 00:00:05.700 --> 00:00:09.200 Most major geological events in Earth's recent history have 00:00:09.200 --> 00:00:14.400 clustered and 27.5 million year intervals, a pattern that scientists 00:00:14.400 --> 00:00:16.400 are now calling the pulse of the Earth. 00:00:18.000 --> 00:00:21.500 Over the past 216 million years dozens of major geological 00:00:21.500 --> 00:00:25.800 events from sea-level changes to volcanic eruptions seem to follow 00:00:25.800 --> 00:00:27.100 this rhythmic pattern. 00:00:28.400 --> 00:00:32.100 The other say that geologist have wondered for really long time. 00:00:32.100 --> 00:00:35.200 Whether there's a certain cycle of around 30 million years, 00:00:35.200 --> 00:00:36.200 in the geological record. 00:00:36.200 --> 00:00:40.100 But until recently, poor dating of such events made the phenomenon 00:00:40.100 --> 00:00:42.200 really difficult to study quantitatively 00:00:43.700 --> 00:00:46.500 In a new study, the researchers conducted, 00:00:46.500 --> 00:00:49.900 a quantitative analysis to see if these events were random 00:00:49.900 --> 00:00:52.000 or if there was an underlying pattern to them. 00:00:53.900 --> 00:00:57.300 To do this, they first searched the literature and found 89. 00:00:57.300 --> 00:01:00.700 Major geological events that occurred in the past 260 million 00:01:00.700 --> 00:01:01.300 years 00:01:02.300 --> 00:01:04.200 These included extinctions. 00:01:05.000 --> 00:01:08.600 Ocean an octagon vent or times when the oceans were toxic. 00:01:08.600 --> 00:01:11.800 Do to oxygen depletion, sea level, fluctuations, 00:01:11.800 --> 00:01:16.000 major, volcanic activity, called blood by salt, 00:01:16.000 --> 00:01:19.700 eruptions and changes in the organization of earth's tectonic 00:01:19.700 --> 00:01:20.500 plates. 00:01:21.600 --> 00:01:24.000 Then the researchers put the events in chronological 00:01:24.000 --> 00:01:27.600 order and use the mathematical tool known as for your analysis 00:01:27.600 --> 00:01:30.700 to pick up spikes in the frequency of events. 00:01:31.700 --> 00:01:35.200 They discover that most of these events clustered into 10 separate 00:01:35.200 --> 00:01:39.900 times that were on average 27.5 million years apart. 00:01:41.900 --> 00:01:43.800 So that number may not be exact. 00:01:43.800 --> 00:01:46.400 It's probably a pretty good estimate the researchers 00:01:46.400 --> 00:01:51.600 say. However, they only looked at the past 216 million years, 00:01:51.600 --> 00:01:53.900 when the dating of such events is most accurate. 00:01:54.800 --> 00:01:58.000 Still, they think the results likely extend further back in our 00:01:58.000 --> 00:01:58.500 planet's history. 00:02:00.600 --> 00:02:03.500 It's not clear what's causing such a pulse and geological 00:02:03.500 --> 00:02:06.400 activity, but the researchers have several hypotheses, 00:02:06.400 --> 00:02:09.400 it could be internally driven by plate, 00:02:09.400 --> 00:02:13.500 tectonics and movement inside the mantle, or it could have something 00:02:13.500 --> 00:02:16.400 to do with the movement of Earth in the solar system in the galaxy. 00:02:18.300 --> 00:02:21.300 The researchers hope to get even better data on The Dating 00:02:21.300 --> 00:02:24.300 of certain geological events and plan to analyze a longer 00:02:24.300 --> 00:02:27.400 time. To see if the pulse extends further back in time. 00:02:29.300 --> 00:02:32.700 They also hope that if one day they can get better numbers 00:02:32.700 --> 00:02:35.200 in the astronomical movements of Earth through the solar system 00:02:35.200 --> 00:02:38.100 in the Milky, Way they can see if there's any correlation 00:02:38.100 --> 00:02:40.400 in the astronomical and geological cycle. 00:02:41.900 --> 00:02:44.800 In any case, if such a pattern exists, 00:02:44.800 --> 00:02:49.000 the last cluster was about 7 million to 10 million years ago. 00:02:49.000 --> 00:02:52.900 So the next one would likely come and 10 million to 15 million 00:02:52.900 --> 00:02:53.400 years.