A strong 6.4-magnitude earthquake struck off Papua New Guinea on Monday but there were no immediate reports of casualties or damage, a spokesman for Geoscience Australia said.

A 5.9-magnitude earthquake shook Iran's central areas on Monday, and there was no immediate reports of casualties or damage, state media reported.

The epicenter of the tremor, which occurred at 17:59 local time (1429 GMT), was 19 km from Qom, about 150 km south of Tehran, the official IRNA news agency reported.

Climate models are reliable tools that help researchers better understand the observed record of ocean warming and variability.

That's the finding of a group of Livermore scientists, who in collaboration with colleagues at Scripps Institution of Oceanography, had earlier established that climate models can replicate the ocean warming observed during the latter half of the 20th century, and that most of this recent warming is caused by human activities.

The observational record also shows substantial variability in ocean heat content on interannual-to-decadal time scales. The new research by Livermore scientists demonstrates that climate models represent this variability much more realistically than previously believed.

Using 13 numerical climate models, the researchers found that the apparent discrepancies between modeled and observed variability can be explained by accounting for changes in observational coverage and instrumentation and by including the effects of volcanic eruptions.

The research, which will appear in the June 18 early online edition of the journal Proceedings of the National Academy of Sciences, casts doubt on recent findings that the top 700-meters of the global ocean cooled markedly from 2003-2005.

"Our analysis shows that the 2003-2005 'cooling' is largely an artifact of a systematic change in the observing system," said Krishna AchutaRao, previously of Livermore's Program for Climate Model Diagnosis and Intercomparison (PCMDI), now at the Indian Institute of Technology Delhi and the lead author of the paper. "The previous research was based on looking at the combined ocean temperature observations from several different instrument types, which collectively appear to have a cooling effect. But if you look at the observational instruments individually, there is no cooling."

But the prayer rituals carried out at the water's edge may not last forever -- or even another generation, according to scientists and meteorologists. The Himalayan source of Hinduism's holiest river, they say, is drying up.

In this 3,000-year-old city known as the Jerusalem of India for its intense religious devotion, climate change could throw into turmoil something many devout Hindus thought was immutable: their most intimate religious traditions. The Gangotri glacier, which provides up to 70 percent of the water of the Ganges during the dry summer months, is shrinking at a rate of 40 yards a year, nearly twice as fast as two decades ago, scientists say.

A number of retailers in Qatar have been forced to shut up shop as high temperatures have hit fish catchments.

The Peninsula reports on June 18th that the combined effects of warm seas and cyclonic winds have hit the available supply of fish, including King Fish and Hamur.

Purdue University could play a role in hardening European honeybees, the bees agriculture most depends on, against threats they face.

Greg Hunt, an associate professor of entomology at Purdue, sees great potential in uncovering secrets of bee behavior, then breeding lines of bees with traits that help preserve their bee colonies.

The National Meteorology Administration issued a yellow code warning indicated prolonged heat and heat discomfort for 22 counties across Romania on Tuesday.

It warned that a heat wave would affect the Romanian provinces of Crisana and Banat in western Romania, Oltenia and Muntenia in the south, as well as the southern part of Moldova (east) and locally in Dobrogea (south east) between Thursday June 21 and Sunday June 24.

Temperatures in the regions are expected to rise as high as 38 degrees Celsius during the period.

"Where did the water go?" asks Ted Shalifor, manager of a marina and campground on Lake Superior's Chippewa Indian Reservation.

The whiteleg shrimp, which is native to the eastern Pacific Ocean and farmed in South America for food, is the first creature ever identified whose male has a monthly reproductive cycle (or "period.") This startling discovery, by researchers at Ben-Gurion University of the Negev, sheds new light on the widespread belief that males are always ready to mate.

Known in Latin as Litopenaeus vannamei, the creature is not really a shrimp, but a prawn that is caught from Sonora in Mexico to northern Peru. A small amount is also farmed off the waters of Texas.

The males of the species produce two "packets" of sperm that are stuck to the female during intercourse. If the male does not use these packets, they are liable to become so hard that the male is unable to ejaculate them. As a result, the sperm in effect have a "use-by" viability date, after which the male becomes impotent.

In the Earth's cold and icy far north, the harsh winters are giving way to spring weeks earlier than they did just a decade ago, researchers have reported in the June 19th issue of Current Biology, published by Cell Press. The finding in the Arctic, where the effects of global warming are expected to be most severe, offers an "early warning" of things to come on the rest of the planet, according to the researchers.

"Despite uncertainties in the magnitude of expected global warming over the next century, one consistent feature of extant and projected changes is that Arctic environments are and will be exposed to the greatest warming," said Dr. Toke T. Høye of the National Environmental Research Institute, University of Aarhus, Denmark. "Our study confirms what many people already think, that the seasons are changing and it is not just one or two warm years but a strong trend seen over a decade."