Bear Stearns was an investment bank that crashed during the subprime mortgage crisis. Although there were subtle signs of a potential economic crisis, the Bear Stearns bankruptcy brought the underlying financial problems to the public's eye. Considering Bear Steans went bankrupt on March 16, 2008, it would make sense that there would be a spike in the search queries for this company.
There were a series of investment banks, insurance companies and commercial banks to go bankrupt in September which can be visualized through the search trends of these companies:
The Lehman Brother's Crash on Sept. 15, 2008
AIG Bankrupt on Sept. 16, 2008
The popping of the housing market bubble next led to the stock market crash on September 29, 2008:
When the nation realized that the entire financial system was falling apart, there was a sharp increase in searches such as "Great Depression" and "global financia crisis". Interestingly enough, we are able to see the geographical distributions of these two search terms. The everyday person would be comparing this crisis to that of the "Great Depression", whereas financial experts(such as those working on Wall Street) would be searching more advanced terminology, such as "global financial crisis". Therefore, in the example of New York, it makes sense that the search words for "global financial crisis" are located in New York, NY, and "Great Depression" was searched throughout the entire state.