Eocene Thermal Maximum 2

The Eocene Thermal Maximum called 2 (ETM -2), and H -1 event or Elmo event was a transient period of global warming that occurred in front of about 53.7 million years. This appears to be the second heat anomaly that marks the long warming trend from the late Paleocene through the early Eocene ( million years ago, 58-50 ).

Both heat anomalies were running in a short time in geological terms from (< 200,000 years ) and were characterized by global warming and massive carbon input into the carbon cycle. The strongest and best- studied event, the Paleocene / Eocene Thermal Maximum ( PETM and ETM -1) occurred approximately 2 million years before the ETM -2, or about 55.5 million years ago. Further heat anomalies followed ETM 2 years ago 53.6m ( H-2), 53.3 million years ( I-1) and 52.8 million years ago, referred to as K, X, or ETM -3. The number, nomenclature, the absolute age and relative global effect of the heat anomalies of the Eocene are the subject of scientific studies. In any case, the heat anomalies seem to have brought about the early Eocene climate optimum, the warmest interval of the Cenozoic. They found definitely before the Azolla event held in front of about 49 million years.

ETM -2 can be clearly recognized in sedimentary structures through analysis of stable carbon isotopes in carbon- leading material. The 13C/12C ratio of calcium carbonate or organic material falls in the course of the event decreased significantly. The events have thus similar to the PETM, although the magnitude of the negative carbon isotope excursion fails less. The timing of the disturbances of the Earth system during the ETM -2 also run differently than during the PETM. ETM -2 continued over a longer period of time than a PETM ( about 30,000 years), whereas the shorter was " recovery time " ( about 50,000 ) years. In both cases, it should be noted that the duration of the processes is very difficult to reconstruct exactly.

Also at widely separated sites featuring a lehmreiche layer ETM -2 in the marine sediments. For samples that were collected as part of the Ocean Drilling Program from the deep sea - eg, Leg 208 of the Walvis Ridge - this layer was caused by dissolution of calcium carbonates. In sections that formed on continental margins - so, for example, that show up along the Clarence River - the loam rich layers are caused by flushing of existing abound soil material that has been introduced into the ocean. Similar changes in sediment accumulation levels were found during the PETM. In sediment samples derived from the Lomonosov Ridge of the Arctic Ocean, can be used both in ETM -2 as well as in PETM signs of higher temperatures, lower salinity and lower oxygen concentration detected.

It is believed that PETM and ETM -2 have had similar causes. However, the study of the exact causes until now the subject of ongoing research. During both events, a tremendous amount of 13C - depleted carbon was spent in the atmosphere and oceans. This led to a decrease in the 13C/12C ratio of the kohlenstofführenden sediments, which explains that take place on a large scale sediment deposits on the continental slopes.

The sharp rise in atmospheric carbon dioxide concentration can explain only between one and 3.5 degrees of the observed temperature rise. According to a 2009 study published in Nature is assumed that other, as yet unknown causes. The authors point out that the potential impact of these factors should also be taken into account in the assessment today of future climate change.

H -2 event was probably an anomaly and smaller heat followed ETM -2 ( H-1) after approximately 100,000 years. This led to speculation that the two events were linked in some way and could have been caused by changes in the eccentricity of the orbit.