The google trend chart is logical, since the event is periodical, and thus attracts way more attention around the time when the events take place, being pretty flat the rest of the time.
An interesting comparison is that of contrasting the searches for 'Bitcoin' against 'Bitcoin halving'. Unfortunately, the former drowns the latter on the chart (as expected) so we cant really see anything meaningful.
Nevertheless, charting each term on a separate window, and extending the period to a 5 year window, we can compare, in relative terms, the searches for both terms both in the days running up to the current halving, and that of four days ago:
Bitcoin Halving:
https://trends.google.com/trends/explore?date=today%205-y&q=Bitcoin%20HalvingBitcoin:
https://trends.google.com/trends/explore?date=today%205-y&q=BitcoinTaking as a reference the 9th of July 2016 and today:
- 'Bitcoin' search term has gone from 3 points to 18 points currently.
- 'Bitcoin Halving' search term has gone from 17 points to 100 points currently.
Both charts are on different scales, so that cannot be compared when viewed independently as above, but the ratios can be compared. While the searches for 'Bitcoin' are 6 fold between halving dates, the searches for 'Bitcoin halving' is basically also x6, leading me to infer that the Bitcoin Halving is just as popular now between the Bitcoin community (including casuals) as it was back in the previous halving. What we do have now is a way larger community (thus the interest has gone x6).
All the above yada yada yada subject the fact that Google Trends displays information in relative terms, not absolute terms (i.e. compared to all internet searches of any term, and then relativized to 100 on the best ratio between searched term vs all searches at a given point in time).