Pollens and Diatoms Will Save the World from Danger

- What we students can do by predicting  the future sea level rise -

In recent years, the sea level rise has been caused by global warming.

We found the way of predicting prospective sea level by analyzing diatoms and pollens from stratums.

〈 Analyze pollens 〉

1）We judged 200 fossil pollens per sample, except pinus, using an optical microscope.

2）Some glycerin jelly were used as encapsulant for aprepared specimen for observation.

3）We calculated the temperature and precipitation in the past, using modern-analog method.

〈 Analyze diatoms 〉※Besides pollens

1）We analyzed 200 fossil diatoms per sample with an optical　microscope.

2）Some pleurax and water were used for prepared specimens .

3）We calculated the salinity of their habitat . They lived in sea water, fresh water, or brackish water.

 〈 Method 〉

1)  We prepare samples.           

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2)  We observe the sample.

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3)  We judge a variety of the sample by using specimen for ovservation.

〈Reveal the sea level in the past 〉

There are some autochthonous indicator species of tidal flats which can tell us how the sea level has changed. In our study, we found Tryblionella granulate in the samples. According to Sato (2014), the spots which Tryblionella granulate were found indicate the sea level of the time they died and accumulated.

We found Tryblionella granulate in

・Pseudopodosira kosugii ― Ａ

・Tryblionella granulata ― Ｂ

・Terpsinoe Americana ― Ｃ

・Giffenia(Nitzschia) cocconeiformis 　― Ｄ

〈 Predict the future 〉

According to the IPCC report in 2018, if the temperature rises 0.5°C by 2030, the temperature rises 2.1°C in 50 years, and if the temperature rises more moderately, 0.5°C by 2052, the temperature rises0.73°C in 50 years.

These facts lead us to the following conclusions;

1)((=80 cm / 500 years = 0.16 cm/years)

2)((=0.2°C /20 years = 0.01°C / years

3)((3.2cm / 0.2°C =16cm/°C )

4)((16cm/ °C ×2.1°C =33.6cm)) － the estimated maximum rise

5)(( 16cm/°C ×0.73=11.68cm)) – the estimated minimum rise

〈 Results 〉

1) Diatoms in the sample tell us about the water of their habitat, and pollens show  the paleo environment of the land.

2) The future sea level rise can be estimated by combining the analysis of  Tryblionella granulate and the calculated temperature in the past by pollen analysis.

【 References 】

Hiroshi Sato(2014)” The use of diatom analysis in reconstructing Holocene relative sea level change. 

※(2019.7.24 up)